I need advice in a big way. My story begins …
About 5 miles from home the temperature gauge suddenly crept up to 3 or 4 bars above 90c, way above anything I’ve ever seen. The gauge did stay green (never turned red) and there was no physical sign of overheating damage when I returned. Checked the heater tank and it was empty ?? Refilled the tank with coolant and the car ran fine. Drove it around the neighborhood and it reached and stayed at normal operating temperature (one bar below 90c). Checked the header tank later and it was only half full … YIKES.
Where was that coolant going? So I drained some oil out of the sump and it was contaminated with water, it looked like chocolate milk. I performed a coolant pressure test and the pressure dropped from 15psi to about 14psi after one hour. Removed the spark plugs and used a scope to look in the top of the cylinders and there was no moisture.
So my guess is that perhaps the head gasket failed between the oil and water passages …
So it looks like the head is coming off. Since the car has 160k I really can’t complain, but I’m really concerned about what damage that water in the oil may have done. I’ve drained and refilled the oil to get rid of the contamination. The car starts right up and runs smoothly with no smoking. I only ran it for a very short period so as to circulate the fresh oil and not risk recontamination.
Anyone encounter something like this ?
Is there any other way coolant could enter the oil other than the head gasket ?
I’m torn between doing the job myself and having my Jaguar Guru do it (app $2000) and a 4 week wait to get the car in ? I do have a very large garage and every tool known to man (according to my wife).
Out of curiosity is there any difference between a 4.0L and 3.6L cylinder head ? Are they interchangeable.