Thread: 3.8L SC Random stalls, faulty intermittent start!

Notice:

If your engine/vehicle is or was ever affected by the engine compartment fire hazard recall this tip is for you!

Background

I'm a 55 yr old accomplished EET who's worked for (Veeder)-KBR, Philips, IBM, Atari, Williams Electronics and a number of high end Hi Fidelity and AV stores, and as a pinball video distributer Service Mgr. and ace troubleshooter, for many years, now a semi-retired web programmer and webmaster/designer.

I studied this seemingly random stalling problem for over a year with my 2000 GTP 4DR 3.8L V6 Supercharged (L67) with 140 KM on it, it worked fine after I bought it 2 yrs ago all fall, winter and spring but started acting up on me last summer usually always on a hot day. The problem just progressively gets worse and worse in any sort of slow traffic and/or hot weather. It now has 196K on it, gets 24-26 MPG, burns no oil, (but still leaks around the heads and valve covers) and goes like madd. Otherwise I really love this car.

The former owner, a truck driver friend of mine (who also had a 2001 2DR for his daughter) told me he had only ever had this problem in the summer a few times and (on this one) the dealer had replaced two of the three HV modules, the MAF sensor, the Fuel Pressure regulator switch, and the Throttle Position potentiometer, but the problem was finally solved (he said) when they put a new CPS sensor and ICM (the driver board under the ignition modules).

It has also had the resistor mod for the fuel pump done. The idiot dealer tech put it over the hot back manifold on the rear firewall I moved it over to the passenger side fender wall which is a much cooler location.

This car also has a new catalytic, new EGR valve, new O2 sensor, and i cleaned out the IAC and tested the purge solenoid, but the odd intermittent behavior continued getting worse and worse.

Due to the incompetence and idiocy of a RapidLube monkey my fuel filter went unreplaced while the moron had twisted the fuel line like a pretzel obviously by not having gripped it properly, they said I should get a new fuel line, because it was "rusted"! This damage to the fuel line by them resulted in the failure of my fuel pump which I (my lawyer) forced them to change and repair the fuel line they had damaged.

I got my recall notice read the report and pulled off the flammable plastic ignition wire holder thingy scraped off all the leaked oil tar crud from the front valve cover dripping out over the front exhaust headers, and rerouted the ignition wires out over closer to the rad, not having time to risk some dealer screwing up something else, I'm still waiting to get my (only one?) new valve cover gasket replaced, just can't be without the car! (My lawyer is interested too)

Symptoms:

Engine runs perfect, great mileage, no engine lights save for odd loose gas cap occurrence. but often it just stalls in city driving and won't restart for a while or won't start after a short trip and park on a hot day.

Problem(s):

Stalls suddenly on hot day usually at a traffic light (brake idle) or immediately after a long traffic light, occasionally will also intermittently stall out in very heavy bumper to bumper traffic, usually under 25 MPH, or after exiting from a highway at/to a light.

Engine may also stall out if the car is parked for 15-20 minutes restarted and run a short time, or may not start 'till engine has totally cooled, never cuts out on the highway over 45MPH

In all cases the engine has no spark, good gas pressure and only a period of cooling time is necessary before it comes back on and runs like a charm again, problem is also worse or likely to happen whenever the car is left parked on a slight uphill incline.

Fire Hazard Problems

Due to TIAE (Totally Incompetent Amateur Engineering) these engines are ill equipped with any actual engine temperature sensing telemetry. The electronic temperature sensor only measures the circulating coolant temperature (what you see on the dash) which is normally around 84˚ to 86˚ C (185˚ F) it will go up appreciably with low octane fuel or on hot days or when the A/C is on. The ECM has only that belated information as a past clue to how hot the block might actually really be.

On Pontiac GTP there is barely no airflow due to the tiny grilles and the low hood design concentrates engine manifold heat under the cowl due to passenger air intake seals and compartment-top can-pressurization the only convective air escape is through the side slots of the hood. A small amount of air escapes under the firewall, wheel wells which is barely adequate when the car is moving over 35 MPH.

Even though the rad is equipped with two dual speed fans, they hardy ever run unless the ECM detects some really high temperature nearing 100˚C (212˚F) in the coolant (only) or if the A/C is on (auto-low). In fact I have never gotten this engine hot enough for the stupid ECM to ever turn on fans for engine heat! The standard program fan trip points are obviously FAR, FAR too high, totally inadequate and outrageously defective! (86˚C would be much better for low, 92˚C for high)

This GROSS TIAE factory defect (no block/head temperature sensor) doubtlessly results in oil damage, oil thinning and burning (IAC evidence), CAT and EGR oil-tar corruption and the serious oil seal valve and cylinder head gasket damage that also resulted in the fire recall !!

Meanwhile there is a horrific low RPM and Parked heat riser build-up in the cylinder heads that normally exhibit 95-98˚C (205˚F) atrociously high cylinder head temperatures even when you use premium gas! . (much worse with regular)

At any rate, I totally hated that heat so put a 90˚C (192˚F) old wall furnace blower thermostat I had hanging around on the rad wedged behind the fan and wired back to ground out the two required fan relays to make the fans come on auto-magically whenever the engine compartment/top of the rad reached that temp. Surprisingly the fans came on quite a bit even in the cooler early summer weather city traffic, though never did the temp indicate anywhere near such on the dash!

In the meantime my stalls became far fewer though still happened especially on hot days, heavy traffic or after parking uphill.

Most interesting was the heat build up after the engine was shut down. Even on a cool day when the fans never ran while the engine was running, after 15 minutes parked they would start up and run 5-8 minutes. But not just once! After ANOTHER 25-32 minutes they would come on again and run for 25 minutes! This indicates heat sinking from the headers back into the unventilated block and heads with no coolant flow !

TDE (Totally Defective Engineering)

Now that I understood what the temperature fatigue cooling defect situation was with this car I got out my remote recording thermometers for a few test ride/sessions. I was sorely tempted to change the CPS and ICM (also reading tips here) but got out the schematics and noticed the "fail-safe" daisy chain configuration. One electonic engineering friend of mine who'd had an old Grand Am told me he was sure it was just the ICM (driver board and ADC (analog timing signal to digital chip and some darlington transistors in a flat pack under the HV coils), and just couldn't be the Hall Effect sensors.

Hall Effect sensors are the most reliable semiconductor switches ever developed they are impervious to wear, not near any heat down low there. and other than physical damage are susceptible to only three types of problems, metal dust/ferrous rust build up, overvoltage, or overdrain-current loading. None of those things could ever happen to them.

Moreover I was looking for a better (stabler) engine block temperature sensing position to relocate my auxiliary fan thermostat to, and that was when I had a revelation! I measured the temperatures on the ICM mounting platform....

The huge cast iron tray that holds the ICM and the HV modules over the fanbelts is bolted to the damned cylinder head! It is baking your ICM! Moreover even though it produces piss-all heat, the ICM is heat sink-coupled DIRECTLY to the engine block's #1 fire hazard producer!

When I measured the fire hazard ICM platform's temperatures they ranged from 199-238˚F!! It is higher than the heads and totally uncooled so cylinder head heat convects UP into it with nowhere to ever go!!! This outrageous heat changes the analog input sensing characteristics of the integrated circuit that receives and converts the CPS engine timing signals from the Hall Effect sensors (also cam one) and in turn directly computes (based on ECM ratiometric and control instructions) and outputs the spark signals to it's high gain darlington output transistors which drive the coils plugged into it! Even without ANY HEAT SINK other than it's own, (hanging loose) the ICM would never EVER get hotter than 125˚F!!

Due to TDE the ICM is being used to cool your overheating cylinder heads! What happens is that when heat rises up into the ICM it's IC gets totally screwed up and it's input buffer is also naturally filtered for both low and high frequency "noise" rejection. When it heats up the resistance values change the filter characteristics especially for low ranges which causes it to lock up and be unable to reliably read the Hall Sensors signals below 1khz (800 hz idle and below especially) The CPS and Cam Sensor are connected directly to it. It's integrator sends the RPM to the Dash/ECM, while it also directly controls ignition sparks.

When the car is parked on a grade uphill the heat rises into the grossly defective ICM mounting "heater plate" even more, requiring a much longer time to cool off! Yhe ICM's mounting platform is an oven-baking component heater, stressing, disabling and and destroying the ICM!


The FIX (ignore the materials mentioned here use the newer improved method in my later post below!)

This will get the car working well enough to drive a while again, but it is not the best solution! Still lets too much heat up into the ICM

One must put a heat shield (or airspace) between the ICM and it's aluminum (so-called-"heat sink" ROTFLMAO) mounting hotplate which is bolted to it's cast iron cylinder head "heat-radiator" platform!

Obtain two approx 3" X 7" pieces of foil (silver or gold metal looking) Arborite phenolic (not truly effective enough, not doing it this way any more! see BELOW)

(Rest here is OK, just that six special washers must be used instead of the two Arborite sheets mentioned above - see below!)

Disconnect the battery positive and set safely aside.

Remove the 6 screws holding the coils and ICM to the hot block platform. You may have to temporarily take off one spark wire boot to get the socket in there on the HV side, replace it loosely immediately so as not to mix them up.

Unplug the HV coil modules and set aside in order (use tape and number them 1.2.3)

Lift the ICM from the heater, you don't need to unplug it but watch out for the passenger side wire near the sharp center bolt-head holding the connector in, bend the (blue) wire down so it doesn't get it's insulation scraped on the stupid connector bolt-head.

Take your six special washers (see below) and place them around the stud-bolts (6 threaded studs) of the heater plate

Lightly re-bolt the ICM to the heater plate with the heat shields in place using the long screws on the lower HV module. (just to hold temporarily)

Get some removable grade Lock-Tite (a dab of Krazy Glue is fine) and permanently remount the upper two HV Modules being careful not to over tighten the bolts (snug-fit and hand tight is good, the glue will hold them! DO NOT OVER TIGHTEN THEM you might crack the HV modules!

Repeat for the bottom HV Module, recheck all cables and HV plugs and reconnect the battery!

Your ICM will now operate at it's own temperature and never cause you a problem again!

Smile and wonder how they stay in business....

Your car will never stall or not start on you again!

PS I relocated my auxiliary fan thermostat to the little 3/4" X 3/4" exposed corner of exposed iron on the upper left corner of the ICM heater plate, the fans function perfectly now as well. The car has run daily over a month now with absolutely no further problems!

After performing the mod above my GTP which was stalling out and not re-starting up to three or four times every single afternoon trip into the city and once or twice on the way home in the later evenings completely stopped misbehaving and has never stalled or not started since.

When I originally added the auxiliary fan thermostat to run one fan (the drivers side fan) at high speed it was noisy (people were saying your car is still running lol) and made no difference in failures. When I chose the relay that runs both fans at low speed, however, I immediately noticed that the wait to restart the engine was much, much shorter! This is because the passenger side fan that is by the ICM platform cools it off!

The ICM heat shield lowers the ICM temperature by about 60˚F which is adequate to solve the defect that makes it unreliable and/or inoperable. An asbestos sheet would be much better heat insulation but that material is a serious health hazard!

For the sake of my battery I chose to let the auxiliary button-type thermostat, now located on the ICM heater platform to run both fans on low, activating R12

Doesn't the Casper's High Speed Fan Switch or changing the fan speeds on HPT/DHP PT make that happen all the time anyway without going through all of that work?

The problem is you need to know the engine's forward (not back firewall) cylinder head (bank 0 I think) temperature! These cars (like most) have no "head" temperature sender, only the one that measures the temperature of the circulating coolant liquid.

At low RPM not enough coolant is circulating quickly enough to prevent heat spikes in the heads nor to measure the true head temperature, especially the front bank head which has no air cooling headroom up to the hood, (header heat is trapped there by the plastic engine cover thingy) due to the low hood-line.

Just like in water and air, in an engine (cast iron, steel or aluminum) HEAT ALWAYS RISES!

If you heat a bar of steel with a torch it melts more quickly with the torch flame applied at the top than it will if you try to heat (melt) the bottom! You have to get the whole thing red hot (saturated sink) to start melting the bottom.

So what is happening here is "heat riser sinking" up into the cylinder heads (valve covers, blower) and the ICM mounting platform! We need to add some added auxiliary air cooling for this riser heat that may not show up in the coolant temperatures until AFTER the (water pumped) RPM rises! Also when the coolant is not circulating with ignition off the ECM has no clue how hot the engine (particularly the forward cylinder head) gets afterwards AFTER the car is parked. (we are talking 45 minutes of serious 200˚+ oil-after-baking, even with fans)

All you need is a piece of wire connected to the upper right terminal (2000 GTP) of Relay 12 to activate both fans on Low. Simply ground the wire (turns on Relay 12) through a switch or thermostat on the head or ICM platform! (will not interfere with ECM should it ever need to activate Both/High Mode either)

Even for regular daily use in heavy summer city traffic I would recommend adding an ignition powered relay to turn the fans on Low (Ground Relay 12 return) FULL TIME (if you don't have or can't find a suitable button thermostat to only do so automatically) while the engine is running, especially if you use lower grades of gas and wish to keep the decorative top plastic cover thingy fitted, blocking upper over the engine airflow convection from the front cylinder bank/headers. These 185˚ button thermostat switches can be grabbed at any HVAC dealer, look up Hunter (cottage/RV) wall furnace "Blower Kit". Those cooling (close on high temp) button thermostat switches are around $15 so a $3 relay might be cheaper but wont help you (or your oil) when the car is parked. We need a furnace "forced-air heat exchanger blower motor" type thermostat switch that only turns "on" when the temp rises above it's value/setting.

Since the ECM only has two transistor outputs dedicated to running the fan relays, one does what I mentioned above (grounds Relay 12) and the other turns on (grounds) both Relay 9 and Relay 10 (hard wired together, so grounding either does both) for high speed mode. Note the polarity use of pins 85 and 86 on GM/Siemens relays is reversed on some relays! Use a meter to find out which side has 12v before adding-in a wire to ground the other coil "return" terminal pin! (to test or activate it)

The big Siemens relay's coil pins are at the lower left and the upper right socket holes. (which is the coil power and which is coil return varies - see above)

To run the fans on high with a switch all you need are 2 IN4005 'blocking" diodes connected to the one wire (again) connected so that the wire can ground 2 (all 3) relays at once as the ECM does (with 2 outputs). The two "blocking" diodes prevent the ECM from ever having to risk running ALL 3 relays with only one of it's output transistors. (Probably not any big deal, but worth noting and paying attention to, do not "jumper" Relay 12's coil return to either Relay 9 nor Relay 10's coil return(s) - use 10 cent diodes!)

This way, (with diodes) even though you have all 3 relays effectively "jumped" for your "fans on high" grounding wire/switch, the ECM can still turn on Relay 12 alone (Low speed) whenever your thermostat switch is not also "calling for" High speed mode (if you wish) cooling! No diodes are necessary to run Relay 12 (both fans Low) alone.

The fans can run in 3 possible modes: (ECM uses 2 fans/both together only!)

Relay 12 ON - both fans on Low (series connected 6v Mode)
Relays 9+10 ON - ONLY driver's side fan runs on High (!2v Mode) (#error - very bad, see below#)
All 3 Relays ON - Relay 12 runs passenger side fan on High (12v Mode)

The middle "driver's fan only" on High mode (R9+R10) above is bad/useless! It just blows (and traps) BOTH THE CYLINDER HEADS HEAT over to the ICM/Belt Battery passenger side and slightly cools the transmission and one cylinder a bit. If you're stuck in bumper to bumper traffic, one fan alone is useless, it just blows heat around like a convection oven, trapped across the rad/grille clearances.

Doubtless even if this was reversed so the passenger/ICM side fan was the single (R9+10) default fan, we'd be "convection baking" the ATC/ABS, tranny and cruise control, it was not a good idea either! You always need both fans on Low or High ONLY, creating positive air pressure sucking/blowing in cold air evenly and forcing the coolest hot air out the bottom of the engine compartment.

Running both fans on High is noisy and definitely not easy on your battery for post-cooling after you've parked the car!

Dude. This is some pretty good info. Do you have any pics of what you did to the coil and fan relay area? Better yet wanna come mod my car since you live near me? Id pay ya.

Important Update:

Seems I spoke too soon, but it's not all bad news!

Using the lower grades of Sunoco Premium, after half hour rides on hot days I'm still having the odd stall, but the engine restarts almost immediately or within a minute! Oddly this happens while the ICM platform is less than 185˚F (or because my temp sensor wasn't too well mounted) and thus the fans are still off

This indicates to me that while I was close to a perfect solution, the problem is still not completely beaten, by the instructions above. Sorry everyone!

This Improved Fix (using the instruction above) addresses two issues with the original "heat shield" mod:

A: Still too much heat is passing up into the ICM
B: There may be an electrical harness EMF spike resonance grounding issue!


The Electrical concern is that the ICM's ground wiring itself (the one wire in the harness) may be inadequate to fully and properly solely ground it properly, especially with regard to "spike generated" HV discharge counter-currents! This may cause excessive power spike/ripple! The ICM still needs a definite physical case to engine electrical ground, even if it's heat sink is not being "cooled" by the engine.

What I have gone to is instead of using the Arborite strips as a full width "heat shield" to just cutting standard industrial Fibreglass composite electronics PCB (printed circuit board) material into 6, 3/4" X 1/2" squares with 3/8" holes drilled in them and using all 6 of them as washers around the studs for the two rows of 3 ICM mounting screws! This creates an air circulation gap between the ICM's own bottom heat sink and the ICM-heater "support/mounting" plates! It thermally isolates the ICM heat sink from the "heater" platform and also takes advantage of air turbulence from the belts to cool the ICM (creating a 3/16" air gap open on all sides) independent of the fans airflow. (see photos to come)

Wrap one edge of each of the 6 drilled PCB "spacer washers" with a single piece of electrically conductive copper or aluminum foil tape so that the ICM's metal case is still certainly well-grounded to ICM heater platform! Note: originally I just assumed contact with any of the 6 locating nut-studs should do this, but just to be sure we aren't insulating the thing, add a ground path with foil tape on one outer edge of each spacer. Use some sandpaper to remove any baked-on salt crystal crud that may have grown on the two pieces of aluminum, this is due to cold saltwater from snow in winter seeping in the edges and then being baked and crystallizing at high temperatures, it may cause the same harness ground-wire only, Counter EMF reactance faults (ignition spike voltage ripples in the 5 volts regulated to the IC) we are trying to eliminate with the foil tape on each washer! Make sure this "krazy 6 output-tazer" thing is physically well grounded to the engine block/mounting platform! (we cannot rely on it's little ground wire in the engine harness alone)


Seems like the mounting/locating threaded nut studs still duct considerable heat into the ICM, and that the solid, full-width two layers of Aluminum/Arborite (the stuff I was using was 60% solid aluminum - DOH!) was still putting WAY too much heat from the ICM "heater" mounting platform into the ICM! When I took it apart, the paper thin Arborite layers had laminated to each other due to the heat! LOL I had imagined the stuff just had a thin foil layer but it was like 80% solid aluminum!

This is an attempt at a line drawing may not look right, basically everything is stacked there and bolted together with the six screws.

Code:

              |   |
       _______|   |_
      |             |       
      |             |
      |             |        
      |             |
  _ _ |             |__ __         
 |_  _________________  __|          < HV module
 |                        |
 |_  _________________  __|          < ICM module
  =  =   air gap     =  =      < Fibreglass PCB washers (3 each side)
TTTTTTTTTTTTTTTTTTTTTTTTTTT          < ICM "Heater" Platform

Edge View (bottom or top)

Using just six fibreglass or phenolic washers around the base bolt-studs wrapped on one edge with conductive tape seems to be the most perfect solution since normal steel washers would just bring the heat up, Try to center the ICM over the 6 heated positioning studs (with just one HV module lightly tightened) so they have minimal contact with the ICM's aluminum heat sink!

Photos for above post:

The ICM support "heater" platform (top of the separate aluminum ICM baseplate shown)

Note the brass colored backs of the three mounting bolts that connect it to the cast iron platform below, that cast iron platform is bolted to the front cylinder head and also part of the engine mount.

Note the salt water seepage and crystallization.



Bottom of the ICM itself showing it's integral heat sink, similar encrustation from salt water.


My original Arborite/Aluminum "heat shield" they were 80% metal sheets, yet the thin Arborite backs melted together by the bottom! (A BAD IDEA-sorry again!)


Top of the ICM showing the location of it's Integrated Circuit heat producing parts (the metal can) note it is down nearest the exhaust manifold but at least on the lower part of the platform. We are now going to allow cooler air from the rad fans to inflow under the bottom and bottom right edges of it!


The piece of spare old printed circuit board (PCB) I used to make the washers


6 cut pieces of PCB being 3/8" drilled


The finished 6 PCB spacer-washers


Applying the grounding tape to one edge


Three completed heat-spacer washers with conductive strips

Placement of the washers in place on the 6 threaded nut-studs on the baseplate before sanding the salt-corrosion crud COMPLETELY OFF, both the ICM and baseplate. ANY grey, calcified aluminum oxide discoloration (aluminum rust) must not remain where you need the 6 contacts it is electrically resistive!

The red and yellow clip leads and my thermostat are also shown, the new, thicker spacer-washers also now allowed me to catch it's ear there to keep it in contact with the cast iron heater. This is the exposed cast iron spot where I first measured the 233˚F with my Tek scope's multiple thermal probes, though the dash/ECM coolant temp read 183˚F (normal).

The ICM placed back on the spacers, it holds in place fine, the studs are much thicker. We're only adding 3/16" of height, still plenty of bolt thread length,



Side view of the ICM and lower two HV coils assembled showing the air gap now produced. On the lower left note the bolt that holds the platform to the cylinder head, on the lower right the harness split where the wires run down to the CSPS and CPS. I'm not really concerned with the ICM failing at 230˚F normal electronic components are usually rated for steady operation only to 90˚C (195˚F), so it's a nice safety feature for the cylinder heads! A new ICM may work for a few months at 230˚F but it will degrade with such artificial heat-aging!

If I have any further temperature issues first thing i'll do now is just add some normal steel washers under the special heat isolating ones! But this fixed the low grade High Octane fuel issue, as well, in 30˚C outdoor weather and busy rush-hour city driving. Note: looking at the passenger side view of the dual-HV-coils here, NOTICE the rusty bolt heads (and on the embedded "third wire" ground washer inside the coil itself) scrape/LCR these three bolts and the coil contact washer to remove all rust from them! They must be very tight and corrosion free for a good "coil ground" 3rd terminal connection to the heater block! Only dribble some Loctite over them afterwards as a sealing varnish to keep water out of that important third common-ground electrical coil connection.


Blue/white "ground me" wire here to the upper right terminal of fan Relay 12 for low speed fan operation, the black wire to the fuse is for ignition power to my HHO cell and a fluorescent grill blacklight. (They get let out the side of the relay box lid by a small filed-out channel above the rad overflow hose)



My auxiliary automatic low speed fan thermostat reconnected with clip wires that run through the gap under the top HV coil.


NOTE": with such an auxiliary fan thermostat wired as shown. the fans really will start "at any time" even when the engine/ignition is off if the engine is hot!

Thanks agentbluescreen. My car is a N/A 3.8 2001 GT, and I do not have stalling, but I was looking at doing this as a preventative measure. I do appreciate the pics, I will be tackling this myself very soon.

Do you think the high temps of the ICM/coil area is whats causing the fires?

Good job!!!

This explains some of the behavior issues with my old retired 1991 olds 98 with 276k on it.

My 06 grand prix appears to have the same design, how many makes / models / engines does this effect anyway?

Originally Posted by SuperSport

Do you think the high temps of the ICM/coil area is whats causing the fires?

That the 3800 community was getting recalls for? No...it was oil leaking onto the manifold and sparking a small fire which led to electrical stuff and that...goes up quick engulfing the whole motor...

Originally Posted by bluegtp91

That the 3800 community was getting recalls for? No...it was oil leaking onto the manifold and sparking a small fire which led to electrical stuff and that...goes up quick engulfing the whole motor...

Kinda hard to imagine oil spontanoulsly combusting...but if thats the case, then so be it. Just kinda thought it would be something electrical overheating shorting out and causing a fire, like the ICM area...

Originally Posted by SuperSport

Thanks agentbluescreen. My car is a N/A 3.8 2001 GT, and I do not have stalling, but I was looking at doing this as a preventative measure. I do appreciate the pics, I will be tackling this myself very soon.

Do you think the high temps of the ICM/coil area is whats causing the fires?

No extraordinarily high oil damaging temperatures, primarily caused from using lower grade premium or regular gas (in city driving) cause the overheating of the confined front cylinder head and the warpage/melting of the plastic valve cover and failure/damage to the frontmost edge of the valve cover and it's gasket, which cause a slow but steady oil leak (that gets worse after parking) out over the center of the cylinder head, that drips oil onto the front exhaust manifold. On factory engines a flammable, decorative snap-on (two lower tabs - one on the drivers side will be already melted) plastic "ignition wire hiding thingy" catches fire (there is not another one on the rear cylinder head, this was just a front-view decorative-dress-up ignition wire guide-hider) from the burning oil, thereafter igniting the flammable decorative top plastic intake manifold cover and then the gas lines. (Supercharged Series II engine covers)

The oil fire ignition danger is especially bad if the car is thus driven for a significant (20 minute distance on such poor fuel) trip on very hot days in slow stop and go traffic and then parked in a garage. The fire will start after about 20 minutes, as soon as the header heat has sinked back up into the now-uncooled cylinder heads opening the small (running) oil leak further.

As I pointed out before the ECM/dash temp indicator NEVER has any/much clue about how hot the cylinder heads ever get, except when the motor is running! It is mis-located way, way down in the coolest middle part of the V block on the nice cold transmission side, down under the rad thermostat-coolant port. Thus the ECM (and you) merely deduces an ASSUMED average running-engine temperature by guessing how hot it might be from the re-circulating coolant fluid's temperature!

As a result of this defect, (poor/improperly too cool location of the coolant temperature sender) the ECM will never turn your cooling fans on when the engine is off and the car is parked even if the engine is literally on fire, not even to blow the little initial flames (starting on the wire guide) out! If you haven't gone in for the recall remove and discard this front HV ignition wire guide immediately, use some tie wraps to hold your longest two front bank HV ignition wires out from the block hanging loosely off the Rad harness! (just a temporary anti-fire fix)

GM will not replace the thus easily damaged/melted plastic valve covers but do freely install and supply a fatter more temperature resistant front valve cover gasket and they remove and discard the dangerous plastic front bank ignition wire guide/hider with some new standoff clips of some sort, that keep those two wires from also being so close to the manifold heat problems. They also do not replace baked wires.

Their excuse for these recall heat damage repair limitations is that "you must have deliberately used bad gas".

I maintain it was a poor design, poorly tested that failed to take into account real long term everyday daily driving situations and conditions beyond the owner or driver's control that inevitably results in damages and deteriorations that they are avoiding responsibility for.

My gas lid does not specify premium fuel only!

The first thing I would do to soup up this engine for racing would be to look into some sort of a set of six (X3) ceramic (like space shuttle tiles) header mounts and ceramic bolt and concentric-nut ceramic washers with a wider set of drilled-out bolt flange custom header mounts designed for the ceramic head-header ceramic heat isolator distances. With such headers it would be possible to cool the cylinder heads 70% more, reduce oil deterioration, thinning and consumption and all the attendant plug and EGR/IAC fouling problems, and guarantee safer cool-downs.

It used to be common to find ceramic transistor to heat sink mounting washers cast in elaborate concentric "wide-brim top hat" shapes to allow screws to be tightened to hold power transistors plated-copper tabs to mica plates against aluminum heat sinks without putting power/voltages onto the metal heat sinks. The thin mica sheets between the transistors and the heat sinks are excellent heat conductors but don't conduct electricity, whereas the ceramic washers conduct neither heat nor electricity, allowing the screw to fasten the transistor to the heat sink with good pressure, yet without making any electrical contact. such flat ceramic "wide-brim top hat" type washers would allow exhaust header flanges to be tightened with their normal metal bolts and nuts through enlarged (drilled out) header-flange mounting holes, and they, coupled with a ceramic "donut" for the exhaust gas port couplings themselves, would completely isolate exhaust temperatures from the all-important combustion chambers/heads, making cooling the engine childsplay..

Get it? No metal to metal contact between the cylinder heads/studs and the exhaust headers! This way you can cool the heck out of the cylinder heads/mixture and blow all the destructive heat you want right out the exhaust ports and be certain it's gone (never to return) forever!

Granted you'd probably need heat sink fins and electric fans to air-cool the headers, but your Catalytic converter would be smiling and you could probably multiply the horsepower by double. It seams that more than half of this "cooling the engine" business is really using it to cool the exhaust headers through the cylinder heads.