Defender TD5 Oil in coolant?

[Shane M]

Hi I went on a long drive when temp gauge hit zero. Stopped immediately and allowed to cool. Realised I had lost coolant.

Enginestill runs fine but still seem to be losing coolant. Also brown oily sludge in expansion tank!!!!.

TRying now to determine whether head gasket or a leak in the oil cooler?

To test head gasket have read you can route over flow from expansion tank into a bottle and run to see if this fills up. If it does it means head gasket gone. Tried this and it did dill but then realised I was routing the radiator bleed pipe as mine does not appear to have an over flow pipe? It is the ball shaped expansion tank.

Can anybody tell me if these have an expansion pipe please?

Because engine has never over heated and runs very sweet could it be the oil cooler and not the head gasket - as this would account for oil in the water?

Does anybody know of definitive test for head gasket failure?

Realise there are lot related topics out there but nothing quite fits my symptoms.

Advice appreciated

[dave88sw]

My money would be on the oil cooler, i've done loads of them now but very rarely had to have a head off unless it's cracked or overheated. For the work involved, i would have the cooler housing off and have a look before having the head off, it's only about 40 minutes work and a gasket if it turns out to be the head.

[Shane M]

Thanks makes sense to try oil cooler first.

But wondering if any way can be certain head gasket has not gone? The coolant overflow pipe in a can sounds reasonable but cannot locate on my ball shaped reservoir. Lots of pics of an over flow pipe on the rectangular reservoirs though - presume these must be for Discovery. Could invest in compression tester but do not have experience so not sure how reliable.

But definitely oil in the reservoir and no water in the oil yet!

Will keep watching post and will tackle at the weekend.

[cackshifter]

There are kits you can get to test for presence of combustion gases in coolant. That would exonerate the head, though maybe the oil would be too much contamination for an accurate test.

[Shane M]

Ok time to remove oil cooler - will reportback in case anyone else has this problem.

[Shane M]

Hi sorry for delay. Oil cooler out and cleaned-covered in light brown sludge! Checked for leaks but no signs. Removed rad which was very flaky and seemed to sag in the middle but no signs of blockage. Ended up removing head (big job but not impossible). Got head skimmed and pressure tested (wards in rugby). Rebuilt with original oil cooler, new rad, replaced plastic dowels!, new coolant reservoir as mine was filthy brown from problem and could not clean. New oil and coolant and so far no problems. Oil staying clean and coolant level stable an bright pink. Conclude from this that either a hose was leaking, rad was shot, or cylinder head was shot - dreaded plastic dowels on the TD5 perhaps. Sorry to be so inconclusive. Also removed the EGR valve now runs all the better for this. I had to make an injector slide hammer plus a fly wheel locking tool. Overall took me probably about two days and few long eves to complete, but happy that Landy is back on the road. Thanks for support and hope this info is useful to someone else.