Thread: How to Mod a LIM

I did the cleaning the LIM, coolant passage block, and the porting out of the LIM passage at the endcap. I went and ahead did this today while I was in there for: New Valve cover gaskets, NEW LIM Gaskets with metal gaskets (not faulty plastic anymore, and it came with the tube of black RTV sealant), new dorman UIM with reinforced/aluminum chimney for the Exhaust Gas Recirculation port, new PVC valve (came with the dorman UIM), new fuel injector O-Rings (6 came with the dorman UIM, and 6 came with the LIM Gaskets), new thermostat gaskets (came with the LIM Gaskets), new map sensor seal came with the LIM Gaskets), new water pimp, new heater hose fittings that connect into the LIM and block, thread sealant for all LIM bolts and water pump long bolts, and cleaning/detailing everything including all bolts (one LIM bolt was so corroded I had to buy a new one).

Here's my ADDITIONAL NOTES for the mods:
Cleaning the LIM:
It's been proven that engines run cooler and better when clean. When an engine runs cooler, it makes more power, it doesn't wear down, and has more tolerance to the abuse you give it. Really this goes for everything in life, something clean runs/lasts/looks better than something dirty.
Coolant passage block:
Use a 7/16" drill bit to make the hole large enough to start the tap. Next, take your time with the tap, that's the key. I thought I needed a special holder for the tap, but no, just the tap. I went to an autoparts store, asked for the 1/4" NPT tap and two 1/4" NPT brass plugs, no problem... OK, I confess it was more a bolt store, than an autoparts store, but similar.
Porting out of the LIM passage at the endcap:
I didn't need any special GM Gasket. I simply purchased a roll of Felpro gasket Material for $3 (aka karropak 3045, O'Reilly carries it), and tapped out the gasket I needed with a ball peen hammer. Now I have plenty of gasket material for anything else I may need in the future... and it was cheaper/closer than driving to the dealer.
Next, I used a [right-angle] grinder and a cutting wheel and very careful grinded out the interfering area.
slap it back together, and voila! Well, OK, it was easy for me, since I happen to have these things lying around.

Above: Motor runs better when warm, its designed to be at the right tolerances when warm. Cooler means you're wasting more power heating the ambient air.

Bill: For the IAT sensor, your info is wrong.

Try an 86 Camaro with a 2.8

^Exactly. "It is designed to be at the right tolerance when warm." The engine when dirty has to work harder at keeping the engine warm, and not HOT. Side Note: Even if you are in frozen over Canada (while I am almost in the tropics), the climate doesn't matter(to an extent), once an engine gets hot then that's what the cooling system is for. The cooling system does a better job when it's not fighting trapped heat. Does an engine every overheat? Yes, it does. Why? Many reasons, being dirty affects those reasons and makes it more prone. Keep it clean. This is mostly likely what matt, above, is saying... not to beat a dead horse.

STANDARD MOTOR PRODUCTS Part # AX1
DELPHI Part # TS10077
AIRTEX / WELLS Part # 5S1007

What size tap is used with this? Will the plugs recess far enough in an l32 manifold to be flush? and can you do this with the LIM on the car?

You can do it on the car if you don't mind aluminum chips in your coolant!

Well i was thinking to vaccuum the coolant out of the port's after i drilled/tapped it to avoid this. Would that be suffifienct enough?

Originally Posted by Maximum Gnarnage

Well i was thinking to vaccuum the coolant out of the port's after i drilled/tapped it to avoid this. Would that be suffifienct enough?

You realize its not much more work to pull the lim once you're this far in right? Yes you'll have to replace gaskets and clean things up but it would add an hour to the job and you'll be left knowing its done right instead of going hmm, wonder where that aluminum is rght about now.

^Especially if you have the updated metal framed gaskets. They're pretty tough, and seem like they would take many removal/installations. If you have the metal gaskets, no problem. If you don't, then get them! My poor factory gaskets made the car unreliable, some times had overheating problems sometimes not, needed coolant from time to time because it was drinking it, left me stranded, risked warping the heads, risked blowing the motor, had to get towed, shorted out a coil from the water in the chamber, and killed my catalytic converter by all the carbon/water that got pushed into it. Not fun.

^Are you talking about the O-Rings on the UIM, where the water passage seals against the LIM? I suppose you wouldn't, but why take them off. They won't hurt anything just leaving them where they are.