Head gasket gone?

Y

Youdey

Member
 Cardiff
I have recently replaced the water pump & thermostat on my 3.0 E85 as the water pump was leaking coolant onto the belts & would occasionally overheat. The car had been out of use on the street for 2 months in the winter before I found the time to fix it. After replacing the thermostat & water pump, I took the car for a test drive around the block to make sure it wouldn't overheat & no coolant was leaking out. The water pump & thermostat fixed the coolant leak & overheating; however, I was going to do an oil change a couple of days later, but when I checked on the oil, I noticed that there was a milky/custard-like residue on the oil filler cap. To me, this suggests that the head gasket has gone. I had checked before doing the water pump & thermostat, & there was no residue that suggested that coolant was mixing with the oil; it has only been since I took the car for a test drive that this would've occurred. So far, this is the only symptom of the headgasket going.

Am I right to believe the head gasket has gone? If it has, is it a good idea to try to tackle it myself?
 
It's not unusual to get that sort of mayonnaise on the oil filler cap when the car has been used very little, especially this time of year when it is cold and damp.

As bigwinn says it's unlikely the head gasket has failed, and M54 engines aren't known for having head gasket problems.

If you take it for a good long thrash the mayo ought to disappear, and anyway who needs a better excuse?
 
Agree with bigwinn and Mr Tidy the white mayonnaise is almost certainly as a result of short runs where the engine doesn't reach its temp to burn off condensation thats built up in the cold engine from it standing. The mayonnaise will find its way into the CCV system so a good clean out of the system is required. A good long run as Mr Tidy suggests may clear it.
 
I've had this worry a few times previously on E36 and E85! It's only ever been "a bit" of mayonnaise under the cap for me, and has always been after I've run it on the drive, or only done short runs into town & back too.

Looking at photos of people where the head gasket has gone they get lots of properly thick mayo under there. Mine's always gone away if I drive it round for a bit and get it up to temp.
 
Thanks all, really appreciate your expertise.
I did take it on a bigger run last night & had a look at the oil filler cap, which looked a lot better than it did before. I have got new oil, oil filter & engine flush to do a service on it soon. I am assuming this would help to clear out the system or should I do something else to help clear it out?
 
At this time of year you can take it for as long a run as you like and it wont clear the mayo out - trust me on this one, mine is the same. Even after the summer I'll still have mayo in the filler cap.
 
Apologies for jumping on this thread.

Possibly have the same or similar issues with a 2.0
I've done compression tests on the cylinders and all results were consistent. I've done a leak test on the expansion tank and the fluid did not change colour so there was no indication of exhaust gases in the coolant.

My next direction is an oil change to verify that it's not over filled due to not having a dipstick and I will intentionally underfill it slightly. 3.75 instead of the 4.25 it needs.
The digital dipstick merely say "oil ok"

I have had the rocker cover off to replace the Valvetronic motor and there was evidence of milkiness but nothing that I thought was bad enough.

The CCV is built into the rocker cover so how do I know if this is functioning correctly? I've had what associated pipes to the CCV off and cleaned.

The engine starts 1st time ticks over smoothly, no dash lights, no fault codes. You wouldn't think there's anything wrong with it.

When I go on a clandestine lap around the block, the white smoke I leave behind is not insignificant.

Currently SORN
 
colb said:
Agree with bigwinn and Mr Tidy the white mayonnaise is almost certainly as a result of short runs where the engine doesn't reach its temp to burn off condensation thats built up in the cold engine from it standing. The mayonnaise will find its way into the CCV system so a good clean out of the system is required. A good long run as Mr Tidy suggests may clear it.
Click to expand...
What would I need to do to clear out the CCV system? Would an engine flush & oil change do the trick? I am thinking of replacing the breather valves anyway, but I haven't ordered anything & I haven't researched what needs to be done labour-wise.
 
Once the CCV system is blocked with mayo, that mayo under the filler cap just won’t go away. On a previous 2.5i, I literally rodded the CCV system with pipe cleaners to get most of the mayo out and that seemed to work, as the system eventually cleared itself.
 
Good long hot run should sort it, otherwise its taking all the system hoses off and blowing them through if there is any gunk in them. Just be carefilif you remove them they are 20 years old plastic and can snap.
 
I had this issue yesterday. The car has barely been driven over the past few weeks or so, just short journeys here and there. Pulled the oil filler cap, and my heart dropped. No coolant loss or excessive white smoke, so I dived into the internet for reassurance.

I took it for a long drive with lots of redline action - these cars do sing at redline - I loved it. Checked again this morning, no mayonnaise, nada, just the sight of brown oil.
 
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