Subject vehicle is a 95 Bonneville SE 3.8 (3800) Non-Supercharged.

Here'* the VIN: 1G2HX52K6S4264365

I posted to "Everything Electrical and Electronic" an issue which involved stall/not starting on this vehicle. This issue was very much a headache. With each stab at a fix I attempted to get the car started. Most of these attempts involved the spraying of carb cleaner or starter fluid into the intake. On more than one occasion this resulted in minor to major backfires through the intake. Once the issue was resolved, which turned out to be a vacuum leak and fuel pressure regulator problem, I started the car.

This start was not a smooth one as some have been. The idle was so rough that I had to give the accelerator pedal some push. I could feel a definate dead miss in one cylinder that had not occurred on previous test starts. Last but not least someting in the rearview mirror caught my eye, a thick cloud of white steamy smoke. I shut the engine down immedately having reved it to about 1500 RPMs to keep it running hoping the miss was transient and involved getting the fuel back to all injectors.

I pulled the oil dipstick to discover the familar milky coolant mixed with oil.

It should be noted at this point that as part of my prior attempts to reslove the no-start condition I replaced the crankshaft position sensor and since I was in so deep also the timing chain and gears and the inturrupter magnet on the cam sprocket. The replacement timing chain cover gasket is a Fel-Pro product. I used the supplied RTV Black sealant on the gasket.

My first inclination was that I'd blown a head gasket in one of the backfire episodes. I read the Techinfo article regarding the intake manafold degredation and failure along with the details related to the upper manafold gasket failure and coolant getting introduced into the cumbustion chamber and oil pan.

Now my question is this. Given this information, and hopefully it is enough, what has happened? Have I blown out a manafold gasket or have I blown a head gasket or is there some posibility that the timing chain cover gasket was improperly installed and that'* the culpret.

You are a fine group of people and I have appreciated the help with my other issues. Thank you all in advance for the guidance on this problem. Grandpa always said walking ain't crowded but it is inconvenient. And I am afoot while the car is inoperable.

If you blew a head gasket, I'd be VERY surprised. I think we've had one or two cases here in 5 years that MIGHT have had one. So just forget that idea for now.

You most likely need to replace the UIM with the APN kit, and replace the LIM gaskets at the same time.

I suggest draining your oil immediately before it starts rusting your crank, rod bearings, and rods.

That is the cause of your problem you have now. Follow what Willwren stated.

I changed the UIM gasket as well as the LIM gasket. There were obvious signs of failure in the middle (cyls. #2 & #4). Allow me to refresh your memory, I had previously replaced the timing chain cover gasket.

Tonight I finally got the engine to crank. To my dismay and disappointment coolant is still going to the oil pan and into the combustion chamber and flooding the intake manifold. What do you think? Do I know own a very expensive fishing weight? All help, suggestions or crying towels appreciated.

When it was off the car I looked at it pretty carefully. I did not find any damage that was obvious. From what I've read here the "plastic" would be in severe shape. Man, I'm going to feel stupid if I find the EGR stove pipe pass through to be leaky now. Of course the car is completely reassembled at the moment. I'll get the UIM back off and re inspect it. Is there any other place where collant can get into the oil and cumbustion chamber? I'm guessing no since the intake manafold is the only place wehre all the elements come so near each other and the only point of entry for the cumbustion chambers.

At least you did not suggest that I take a fishing trip [see also: ref to my previous post]

When I grow up I want to be a doctor or a laywer, or a cafe cook but I reallly don't want to be a mechanic. My highest regards and respect to all gearheads.

Defintly take another look at that UIM. Iirc there are pics that show you what the damage looks like.

Probe the plastic in the UIM around the stove pipe area. Sometimes, it can look good and solid because of carbon build up. But, when you start probing with a sharp point, you may find it quite soft, or that the probe will go right through. A visual inspection may miss it.

I hate to be a total idiot, but what the heck is lirc? Now I can't find the picturesof the damage to compare to what I have out of the car.

All help appreciated on this issue.

If I recall/remember correctly