It looks like it’s my turn.

[356to966]

A few weeks ago, our 02 Cab started losing a bit coolant. At first I thought that I had one of the common leaks or just needed a new coolant tank cap. No such luck. Now, on cool starts, I’m seeing an obvious plum of vapor coming from only the left exhaust pipe. There’s no sign of intermix of either type and no CEL though.

With any other car, I would be thinking "head gasket" but Jake Raby of LN engineering has said on the Rennlist Forum that it is never the case.

Does this sound like a cracked head or can it be anything else? The car has nearly 90K miles on it but has recently had the IMS retrofit and other preventive work done so it would be a real shame to have to replace the engine.

Any advice would be much appreciated.

[Loren]

When you say no sign of intermix are you just looking at the coolant tank or did you drain the oil and look for coolant?

Cracked cylinder liner or head gasket will both look the same with coolant in the oil. Best to do a compression check on each cylinder too.

[JFP in PA]

The M96 engine is not very prone to killing head gaskets, more often it is a head cracking issue. Might also be a good idea to pressure test the cooling system when you either compression test or do a cylinder leak down on the block.

[356to966]

Thanks for the replies Loren and JFP. Loren, There no sign of coolant in the oil or oil in the coolant. JFP, Looks like I need to find a P shop with experience in water cooled engine failures and do some testing.

[987_RDC]

Drain and vac test the system.