Head gasket failure or something worse??
 

Ok I think one of the head gaskets has failed on my 2.8 cabbie (using water and mayonnaise in the filler cap).

BUT I'm also getting low oil pressure 0.5bar when hot and oil warning light, is this connected to the head gasket or is something more serious going on :wall:

Head gasket's pretty serious isn't it!.:lol: i doooo hope you are not driving it?

Head gaskets I can deal with, if its bores, rings etc i am getting out of my league don't want to change the head gaskets and still find I have low oil pressure.

No she is a driveway queen at moment while i get the other jobs done to her...

It'll lose oil pressure through the gasket though, won't it?

Normally the head gasket gets burned between the pot bores and / or the coolant bores. Sometimes the oil return is leaking at the gasket. But I'm not sure whether the pressure circuit might fail at the head gasket. So you should have visible oil leaks, excessive oil consumption, or a clearly recognizable coolant / oil blend.

Not sure as almost all other head gasket failures I have had over the years has been a catastrophic cloud of white smoke rather than what I have on this which is some coolant loss mayonnaise on the filler cap and low oil pressure.. :finger::shake:.

The only oil/water mix I am seeing is mayonnaise on the oil filler cap. No obvious external leaks that I can see...:shake:

Mayonnaise might also appear under cold and wet weather conditions when the vehicle is mainly operated on short trips. So the engine doesn't reach it's serious operating temperature.
Due, oil might be thinned with condensates, causing declining oil pressure.
I would change oil an filter first.

Yes my brother suggested that as well, car has been off the road for around 2 years prior to me buying it so oil could easily be goosed.

Will give it an oil change at the weekend and see what happens...:tup:

Going back to my days at the dealer now. We did MANY head gaskets on 12V v6 engines, was always oil leakage. Usually they leaked when piping hot at RPM. The place to look is in the valley between cylinders 4 and 5 (front two of your passenger side). Get it good and hot, clean aggressively and hold engine at 3K revs. Watch for oil forming at head to gasket joint.

The other common failure is the oil cooler, check the overflow bottle for oil residue. Due to differential pressures the two fluids go either way (kinky, no?). When the engine is running the oil pressure is higher so oil migrates to the coolant. After shutdown the cooling system pressure is higher so coolant migrates into the oil.

Hope this helps, Cheers.


Dan

:p

Is it overheating or anything? Might just be phouked...:lol: compression test, hot and cold.:hmmm:

If I heard him right, the only symptoms are Mayonnaise and low oil pressure. No overheating, no trace of oil in water / water in oil.
And mostly Mayonnaise on the filler cap (only) is evidence for cold engine operations with resulting condensates - not more.

Yes I know.:tup: I've had that in a few of mine, mayo, and in the breather pipes too. A good oil change and longer drives as you say.

A very good hint! The crankcase breather should be cleaned as well and after renewing the engine oil proceed a longer trip on a motorway.

Going to drop the oil and filter at the weekend and clean out the breathers and see what happens, providing I can get better oil pressure than the 0.5 Bar at idle Im getting now I will give it a decent run.

To answer the other question, no it doesn't overheat it's just dropping oil pressure (5 bar when cold dropping to 0.5 bar when hot) and mayonnaise in and around the filler cap and using some water.

Cheers for your help guys...:tup:

Guess what now the weather has decided to warm up a little I decided to throw a new oil cooler on today prior to pulling the engine out (I have a spare engine to put in) and it's solved the problem :tup:

Got plenty of other issues to sort out but at least at the moment this is one less headache...:cool: