I have read tons of posts about coolant in cylinders but have not found a satisfactory answer to my problem. After the car was running perfectly the next morning the engine was locked up due to water in one cylinder. I took the upper and lower intake off and didn't find any coolant in the intake. The LIM gaskets were the old plastic ones and 3 of the 4 coolant passage holes were cracked. There does appear to be some oil in the coolant but no coolant in the oil.
I have read many posts claiming that the LIM gaskets leaking can cause coolant in a cylinder. I don't see how. The coolant ports in the gaskets have holes next to them leading into the crankcase not into the intake port. If it'* possible can someone explain this to me? I'm thinking head gasket but the car has never overheated as far as I know.
Thanks,
Joel
My UIM has been replaced at some point in the past. It has an '04 date code and the car is an '00.

The coolant will be sucked into the cylinder under normal engine vacuum. When the engine is off, coolant will flow in the easiest path towards gravity it can.

You said the manifold was an 04? Those gaskets are probably 8+ years old. Replace the lower ones with aluminum framed gaskets and you should be set.

I also believe there is a different style egr stovepipe to prevent cracking your UIM under hot conditions.

Thanks but that doesn't answer my question. From your answer the only way coolant could get in the cylinder is when the car is running. I can't see how it would get in there either unless the intake filled up which it can't because it would run out the throttle body.

I was referring to the gaskets between the LIM and cylinder heads. Thats how the coolant gets in there. If it was the UIM gasket, then it would jus puddle in LIM valley. Seen it many times.

I'm still looking for an answer to how? The heads have slots in them between the coolant passage and the intake port that leads to the valley. I can't see how the coolant could jump that hole and get into the intake port. It seems to me that it would just fill the crankcase instead.

Sometimes it does. It just depends on how the gasket allows the coolant to flow. Believe me sir, it really depends on Murphy'* Law, or the wick effect.

Which cylinder was full of coolant?

If it was a headgasket, you would be taking compression to the cooling system, and that is usually pretty apparent when it happens. The only other thing I can think of would be a cracked head. Otherwise, the UIM/LIM is the most likely offender.

Have also seen the upper intake manifold rot out near the EGR passages and cause the same problem, wouldn't hurt to change that too!