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Sludge in Coolant

orange57

orange57

New member
So when looking over the car last night, the coolant appears to be brownish, and when I remove the raidator fill spout there was what looked like oil sludge on the cap. I read on here it could the the trans cooler leaking into the coolant. is there a way to check this before just blindly replacing a radiator?

Also saw some people mention the LIM, is that the lower Intake Manifold gasket? How difficult is that to remove and replace on an 04 GTP? Is there a write up?

Thanks,

matt
 


You may just need a coolant flush if youve never had one done. Air can cause it to sludge or mixing it will too. As for the LIM yest thats Lower Intake Manifold gasket and as far as difficulty I dont think it would be terrible just time consuming. Ther is probably a writeup someplace here.
 
you need a coolant flush, its the dex coolant sludging up.

lim gaskets are pretty easy, search youtube for lifters in 33 minutes, it covers most of the job. and then theres plenty of threads here that cover parts lists and such.
 
I didn't realize the Dexcool was so prone to sludging. My Cadillac STS also runs Dexcool, and when I flushed the system about 4 months ago (Car is an 05 with 81K on it) there was no sludge build up.

The flush is on my list of things to do. Just wanted to make sure it wasn't possibly more serious. :)
 
I may switch over to the green stuff. Will also have to make sure to fllush the system regularly. here in AZ the cooling system is nothing to neglect.

We ran Dexcool in the 89 Olds with the series 1 3800 and never saw an issue with sludging in that car either.
 


If your lower intake manifold is leaking your check engine light should be on. At least mine was when it was leaking, but my dexcool didn't get filled with sludge.
 
the lim gaskets should be done on general principals really. they are failing as we speak.

if you do the job yourself and shop smart, you can get it done for around a 120 in parts or so.
 
you'll need the lim gaskets, the upper plenum gasket, coolant elbows, a oil change, and a 1 gallon of antifreeze. and some thread sealant for the lim bolts.
 


the 04 gtp should have metal lim gaskets they dont fall apart like the plastic ones did, i would flush the dex crap out of it tho and switch to green
 
1quick said:
the 04 gtp should have metal lim gaskets they dont fall apart like the plastic ones did, i would flush the dex crap out of it tho and switch to green
Click to expand...
Not so... some early 05's still had plastic LIM gaskets.
Nothing wrong with dex cool except for the fact it dosn't last for 5 years or whatever they claim, flush and change it out every couple years like the green stuff and no problems.
 
1quick said:
the 04 gtp should have metal lim gaskets they dont fall apart like the plastic ones did, i would flush the dex crap out of it tho and switch to green
Click to expand...

hes got a good chance of having plastic gaskets from the factory, every 04 ive seen here has had plastic lim gaskets. GM must have been using up old stock for a few years.
 
Looking at Rockauto, there are several options for the LIM gasket. Does anyone have the P/N handy for the upgraded version? There is AC Delco P/N 89017825 and Felpro P/N MS98014T are both of these the upgraded version? They look to be metalic, but cant' really tell and the description isn't very good.

Thanks,

matt
 


Ok well let me clear this up, you guys seem to be leaning towards the LIM gaskets failing causing this sludge on just a hunch, when many things can cause it. It could possibly be the cause, but more likely someone mixed the wrong coolant, or there was air in the system for a long time.

First check to see what gaskets you have. Most of the time you end up with the plastic gaskets that will fail since they didn't put them in til mid 05, but if you aren't the original owner you never know if they were replaced with aluminum gaskets before you bought it. Mine were.

Then make sure there is no coolant in your oil, and that you aren't loosing coolant, the overflow level should be where it needs to be. If it is, the gaskets aren't leaking...yet, if they're the plastic ones. If this is the case there was either air in the system or someone mixed coolants. If there's a lot of sludge someone probably mixed, but if there's just a little bit floating or some on the cap air is probably the cause and a flush is the solution. I would flush completely with water getting all of the old stuff out, then refiling with conventional green. Dexcool does it's job but is way too picky.

Also you asked is there a way to make sure the radiator isn't failing letting oil in the coolant. You can just check the trans fluid and make sure that coolant isn't in the trans, and also make sure the level is where it's supposed to be.
 
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these will work. i used the acdelco set myself. look for some discount codes as well.

this is off the rockauto site. for a 04 like you have.

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[TD="class: partlayout"]ACDELCO Part # 89017825
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GASKET KIT,INT MANIF[/TD]
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the set i installed on my car.

limgaskets.jpg


the old plastic gaskets, see the smaller ports, how they are deformed and some what blown out. thats the failure.

limjob7-1.jpg
 
02NavyBlue said:
Ok well let me clear this up, you guys seem to be leaning towards the LIM gaskets failing causing this sludge on just a hunch, when many things can cause it. It could possibly be the cause, but more likely someone mixed the wrong coolant, or there was air in the system for a long time.

First check to see what gaskets you have. Most of the time you end up with the plastic gaskets that will fail since they didn't put them in til mid 05, but if you aren't the original owner you never know if they were replaced with aluminum gaskets before you bought it. Mine were.

Then make sure there is no coolant in your oil, and that you aren't loosing coolant, the overflow level should be where it needs to be. If it is, the gaskets aren't leaking...yet, if they're the plastic ones. If this is the case there was either air in the system or someone mixed coolants. If there's a lot of sludge someone probably mixed, but if there's just a little bit floating or some on the cap air is probably the cause and a flush is the solution. I would flush completely with water getting all of the old stuff out, then refiling with conventional green. Dexcool does it's job but is way too picky.
Click to expand...


no one said bad lim gaskets caused the sludge, they should be changed as part of the engines new owner maintenance, along with all the other tune up related crap one does when they buy a used car.


dex does sludge up for all the reasons you stated tho, air or mixing of coolants being the biggest culprits.

if you look between the head, and the lower intake, you can see the gasket, if you see black, its the old crap, silver, and its been upgraded already and can be left alone.
 
Right, it's good that you guys encourage changing the gaskets as a preventative thing, but at least make sure the OP knows that's why you're encouraging it, not because we think that's the solution to this thread's problem. It wasn't exactly worded that way but it comes across.

He said the coolant is actually brown, that's usually due to mixing coolants. If it's still red/orange with a bit of sludge at the top it's from air.
 
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