Hi everyone, I am new here and haven't worked on my own cars for 30 years. I watched my 2002 Bonneville turn 111,111.1 miles a few months ago and it has been down hill ever since. Long story to include all my problems here.


my most pressing issue is that about a week ago my intake manifold gaskets failed. I have suspected them for a while with some of the other problems I have been having. last week the car threw a P0303 code. My ICM, plugs and wires were all changed about a month ago (ICM problems since May). when I pulled the #3 plug it was wet, 1 and 5 were dry and normal. I ordered the parts to replace the UIM (ATP) and LIM gaskets (Fel-Pro metal carrier). I am going to tackle the job this afternoon.


I am almost positive that some water has gotten into the oil. I have read some post that indicate that this could be a major problem. the post specifically talk about "Coolant" getting in the oil. Is the concern as great if it is only "Water"?? I have been chasing a leek and had the water pump fail. I back flushed the cooling system which I think caused the manifold gaskets to fail the rest of the way. after the water pump and flush I was running just water till I found and solved the leek.


I know from the posts I have read that I will need to do several quick oil changes with filters over the next few weeks. what the post don't discuss is are there any oil additives on the market that should be considered to try to mitigate any further damage? are there any other steps that should be taken to reduce the possibility of a catastrophic failure. Money is extremely tight and I need this car to keep running.


the engine is a 3800 series 2 (vin code K)


any help would be greatly appreciated

I wouldn't take any chances with it, especially when you caught it so quick.

You likely have coolant in the oil (mix of antifreeze and water) since straight water will boil off the first time the engine gets to operating temperature. I doubt the back flushing cause your problems. A couple of quick oil changes should do the trick.

Is it possible to take an engine apart without breaking something? I broke the connector on the throttle position sensor, found a bare wire to one of my injectors, and a brittle hose to my evap purge valve.


I am finding a lot of crud that never flushed out a few years ago when my Dex-Cool turned to mud.


it appears that most of the water loss was from the LIM onto the transmission. With all the stuff in the way I just didn't see it. there is a small amount of oil/water mix (creamy stuff)on the oil filler neck. Is it possible that is from the water boiling off. No sign of creamy stuff on the dipstick. No sign of separation either.


thanks for responding

If the vehicle frequently took short trips, it could be condensation. Also, if it'* just water, all of the water will be at the bottom of the oil pan.

It'* the milkshake throughout the crank case that is the big worry.

But we are also talking about $20 worth of oil at the most, which in my opinion is cheap insurance.

I have driven Bonnevilles for 720,000 miles (3 cars combined, 1989, 1993, 199. Never had any problems with the bottom end. Do a proper job replacing the LIM, UIM and coolant elbows. Replace a that old vacuum line to the purge valve with a new one from the dealer (about $30) and you should be good for another few years. Naturally this is assuming the rest of the car has been cared for and is in good shape.

when I pulled the intakes everything looked fine. I pulled the front valve cover and the cover itself was coated in white. The springs, rockers, and head had no sign of white. Car has only been driven 3 to 6 miles at a time since the problem started. I am leaning toward it being condensation from running straight water in the cooling system. I am going to pull the rear valve cover and clean it out like the front one. Just a pain to get that one out. I figure I may as well drop the pan when I get the top put all back together. Clean things up the best I can and hope for the best.


Anyone have any tips on what I should look for while I have the pan off? I have never worked on that end of an engine before.

Unless you have an oil pan leak or can hear rod knock I would leave the oil pan well enough alone. Yes, coolant in the oil will take out the main bearings if not caught in time, but from your posts I believe you're going to be ok especially if your oil psi is still within norms. Just do a couple of frequent oil and filter changes, no point in going "Monk", there'* something to be said if it ain't broke, don't fix it.

2004 Bonne SLE
1971 Chevelle SS

My dash oil gage reads normal pressure when driving and at start up, but drops 20psi when idling at normal temp. this has been happening since I did an oil change the end of July. I used a Fram filter. I read a thread where others have had this same problem with the Fram filter. I picked up an AC Delco filter. Hope to have everything back together tomorrow.


I don't know if I can fight the urge to drop the pan. Curiosity gets me in so much trouble. if I don't drop the pan I'll wonder if it need cleaning out. If I do drop the pan and find problems, I can't afford to fix them.

Don't drop the pan, there'* no need for it. Get the LIM job done, get the oil changes happening, get a long drive going to get the oil hot enough to boil off the rest of the moisture.