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LIM Gasket replcement, coolant in oil, smoke

O

ohbrady

New member
Hello everyone.

I have an 03 Grand Prix GT that sat for 2-3 years without ever being started or anything. With a new battery and new fluids we got her started up. Oil was leaking from the front valve cover gasket so we replaced that gasket. Was some white smoke coming from under that valve cover area.

There was a little white smoke coming out of the tailpipes on startup. After running a while you'd get some drops coming out of them. The smoke would go away after a while. Stinky coolant smell while running. I decided to change the LIM gaskets and the upper plenum gasket, along with the gasket for the throttle body.

Started it up and it ran horrible. Let it run about 20 seconds. Turned it off and checked oil... full of coolant.

I tore everything back apart and got it all cleaned up again with a razor blade. Was extra careful this time. Got it all put back together and was feeling pretty good about myself. Changed the oil and added fresh coolant.

Started up much smoother this time. Ran good for about 30 seconds then the motor started jumping around. Turned it off and checked the oil... full of coolant again.

I am not sure how to proceed from here. Was the white smoke coming from under the front valve cover area something to do with the head gaskets? Could fixing the LIM leaky gaskets cause the head gaskets to go? Any help would be appreciated. thanks!
 


I started the project with fresh oil/filter. After the first failed attempted I changed oil/filter.

I did not replace the upper intake. It appeared to be in good condition.

The second time I took it apart the top of the LIM was dry. The first time it was covered in oil.

I will check out that thread. Thanks!
 
To change lim and upper intake gasket you've got to drain as much if the coolant before hand as possible. There's a few ways to accomplish this... I've used a shop vac with a bucket and lid set up to catch coolant but not allow it to go into shop vac basin. Anyways, prior to putting lim back on, you drop some oil down the lifter valleys to wash out any coolant that may be laying in there... When replacing the gaskets, make sure you use some RTV on the rubber ends, especially in the corners. New valve cover gaskets (front and rear?), did you change the grommets too? Then before start up, you drop the oil and replace with new, that oil comes out as well after a short trip... Is worth the ounce of prevention. if you can't get it up to operating temp, you can't do a compression test to see if head gaskets are shot, but not sure why they would be...? Are there any leaks anywhere else? Side of engine? Oil pan covered in oil?
 
So since the LIM was dry when taking apart last time, is it safe to assume my problem is likely not the upper plenum?
 
Your UIM will only fill your LIM and then hydrolock the motor. It won't put water in oil. A bad gasket job could allow water to get into oil. You'd have to have really not cleaned or totally buggered the job in order to have that happen.
 


I am trying to figure out what is going on with my 3800 series 3. It’s got a random misfire and I can’t seem to figure it out. I’ve changed coils plugs wires icm fuel pressure is good just did upper and lower intakes, changed maf sensor and pcv valve and it didn’t change anything. Compression is good. I’m about to blow it up I’m sick of throwing money at it changing parts and nothing works. Any advice would be greatly appreciated.

Thanks, Grandprix94
 
coolone said:
To change lim and upper intake gasket you've got to drain as much if the coolant before hand as possible. There's a few ways to accomplish this... I've used a shop vac with a bucket and lid set up to catch coolant but not allow it to go into shop vac basin. Anyways, prior to putting lim back on, you drop some oil down the lifter valleys to wash out any coolant that may be laying in there... When replacing the gaskets, make sure you use some RTV on the rubber ends, especially in the corners. New valve cover gaskets (front and rear?), did you change the grommets too? Then before start up, you drop the oil and replace with new, that oil comes out as well after a short trip... Is worth the ounce of prevention. if you can't get it up to operating temp, you can't do a compression test to see if head gaskets are shot, but not sure why they would be...? Are there any leaks anywhere else? Side of engine? Oil pan covered in oil?
Click to expand...

I did clean out the best I could under the LIM, but did not put any oil in the valley. Used RTV. Only replaced the front valve cover that was leaking. Have not done the rear yet. Did not change the grommets. I don't see any leaks around the engine.
 
Everything was clean. Used a razor and some acetone. Smooth as a babies bottom before the new gaskets went on. Everything lined up, bolts went in easily. I didn't clean it with a razor the first time so wanted to rule that out. I just don't understand how replacing the gaskets made things worse. And last time I tore it apart the LIM was dry.
 
could be a blown head gasket leaking the coolant into the oil then. did it over heat at all? and the upper intakes do fail like stated in that link i posted.
 
Oil in the LIM is expected. The PCV drops the oil vapor right above it and in a lot of cases the #2 and #5 areas where the hidden bolts are, can be full. If you allowed that oil to go into the cylinders, you can expect smoke for a good while.

I will go back and read further. I skimmed.
 


Ok.. looks like you are getting water in oil. Apparently a decent amount. Head gaskets are so uncommon that I typically rule it out w/o giving it a thought.

On the valve cover grommets: the reason to change them is that the bolts have spacers around them and bottom out. The grommet provides the force to hold the cover down and ensure the gasket does it's job. An old or smooshed grommet will not provide that.

Now.. let's talk coolant in oil
If you used plastic gaskets, you need to ensure the tabs are in the holes of the heads. Metal gaskets don't have those tabs. All gaskets are symmetrical and have two coolant port holes even though the LIM only has one per head. For coolant to get in via cracked head or head gasket, you'd need the engine to be up to temp typically. And it's quite uncommon. Actually coolant in the oil isn't overly common and usually caused by LIM gaskets being old.
 
Was not overheating. Drove the car a few tmes for 10-15 minutes at a time. Let it idle for 45mins+ a few times also. Did seem like excessive heat coming from under the hood but I don't know. Was nothing like THIS oil/coolant going on.
 
I used the plastic gaskets. I made sure the tabs were in the holes. The engine is not up to temp. This last time I started it for like 10 seconds. Checked oil. Small amount of coolant. Thought maybe its leftovers. Started up again for like 30 seconds. Checked oil, way more coolant. Maybe my new gaskets are junk? Maybe I'm worse than I thought at following directions? I can try this one more time. Maybe try different, new gaskets again. Just wanna try and be sure I'm not fixing the wrong thing.
 
Well, if you're doing them again, you'll have the chance to inspect. Check the LIM for pitting and use better gaskets. I had to redo some on a 4.3 because the LIM slid on the back of the engine, and probably smeared the sealant on the end. (hurried too much)

Got bubbles goin in the overflow tank with it running?
 


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