head gasket or other oil leak xm 2.5 d

jasoncort · Post by **jasoncort** » 06 Sep 2007, 17:26

I have a bad problem with oil in the radiator-in fact it is mostly oil! The engine oil leaks in to and pressurises the cooling system unless I run it really low. Performance is fine so where is the problem most likely to be?

citronut · Post by **citronut** » 06 Sep 2007, 18:48

oil in the rad is head gasket, unless you have inadvertantly pourd it in your self
regards malcolm

andmcit · Post by **andmcit** » 06 Sep 2007, 21:45

Pressurisation of the system is a fair sign of a head gasket failure.

Is it actually any worse than it usually is as it's an aspect of the car
you may not normally be interested in or aware of in its characteristics?

I have personally had the misfortune on an XM v6 that had a failed water
to oil cooler heat exchanger with similar results to your problem. You must
watch the oil - it will rot out the rubber of the hoses in the cooling circuit.
Check the obvious and discount it before a head off job!

Andrew

AndersDK · Post by **AndersDK** » 06 Sep 2007, 23:28

Yes - check the oil cooler. The can which is loacted behind the oilfilter and have 2 coolant hoses leading to/fro.

Once problem found and solved :
Flush the coolant system first using tapwater, reverse flush it as well. Then running the engine hot, use the red coolant stuff 50/50 mix a couple of times. Let engine cool off before changing coolant

Flush your engine using a 5Wx or 0Wx synthetic oil running the engine hot. Then change the oil and filter.

Post by **Peter.N.** » 07 Sep 2007, 10:09

I agree with Anders, check the oil cooler first. Look at club-xm.com there are a lot of 2.5 owners on there. (Sorry Anders, I'm not trying to poach your subscribers!)

jasoncort · Post by **jasoncort** » 09 Sep 2007, 16:37

Thanks for the tips most helpful and my problem is solved in part. I have by passed the oil cooler and pressure is now normal. However I have to cap off the oil cooler end as oil is flowing out of the water inlet and outlet pipes.
Are there standard fittings for this job?

Post by **Peter.N.** » 09 Sep 2007, 17:34

I would replace it if I were you, unless you only drive very gently!

AndersDK · Post by **AndersDK** » 09 Sep 2007, 19:50

The oilpump is capable of delivering an oil pressure of at least 4bar, so you need some pretty good end caps to keep in the oil.

For a quick bodge use a lenght of the surplus water hosing - you must have removed by now - and loop the 2 studs with this.

andmcit · Post by **andmcit** » 09 Sep 2007, 20:48

Great - now you know the failure/fault, a remedy is far easier!!

The ideal solution is a proper replacement rather than a bridge of
the pipes;a good short term solution but they'll deteriorate with the
oil attacking the rubber.

You MUST thoroughly flush the cooling system to banish all traces
of oil and in fact you must suspect the health of ALL the cooling pipes
if this has gone on for some time.

They'll be a real git to find/buy/replace so try and save them asap!!
You have to suspect the high points/bends on all the pipes at their
uppermost points as the oil will collect in these areas and in high
concentrations wrecking havoc with their strength and watertightness...

Andrew