Really strange Problem

[lancer]

Hey hope yous can help with this.


I have a 2000 406 HDI 90bhp and the header tank was overflowing with oil and water mix. Now i thought this was a head gasket and replaced it but when the car runnung same thing happened again now also got the oil cooler pressure tested before replaced head gasket and was told it was ok. Now the header tank is full with oil and water mix again and car is not overheating and runs at normal temp. When i went to take the oil cooler off again to get it double checked i found that the water hoses had no tarces of oil in them, now this i couldnt understand as the oil is overflowing from the header tank.

Does anyone know any problems that would cause this e.g water pump and if so where would it pick the oil up from with out causing the oil to be though the pipes on the oil cooler. As i thought the water pump was working ok as rad is heating up ok etc.


Hope someone has a clue because i am stumped by this.

[Doggy]

Guessing here, but oil will float on the surface of the water....
Just possible you've cured the original problem, but failed to get all the oil out of the cooling circuit?
Try draining, flushing & re-filling the cooling system, then monitor it closely.
(I'm assuming you have no other tell-tale problems, [water in the sump /milky looking oil / low oil pressure])

[lancer]

Flushed the system 3 times and every times water runs clear.

No other signs at all.

[Doggy]

Is your sump level dropping?

Could you run it gently without passing water through the cooler, (join the 2 water hoses with a piece of copper pipe or similar), to prove a point? Have you got an oil temp gauge?

It may be that the cooler only leaks when it's hot - if this is the problem, the water pipes on the cooler should fill with oil in time.

[lancer]

Yeah oil level dropping and no i dont have a oil temp gauge was thinking of bypassing the oil cooler but wasnt sure if my oil would over heat?

[Doggy]

Depends on the kind of driving you do - mine runs at about 130 degrees maximum and takes at least 10 miles to reach that temp in the summer, longer on the winter.

Honestly don't know how heavily it depends on the cooler, but I would have thought you could have got away with it if you take it steady, particularly on fairy short runs, maybe coast in neutral when you're slowing down, that sort of thing. I guess a few days will tell you for certain if that stops the oil build up in the header tank.

If you need another one it looks like a scrappy's your best bet - its nearly £170 from Pug
1103N1 DISTRIB CHAMBER £169.82 (EP 69,2 Valeo Thermique)

[Welly]

How did you get to the oil cooler? I never ever found mine by-passing it won't hurt as long as you don't race the thing. The oil cooler is more about extending the service life of the oil by keeping a lid on it's temperature. @ doggy your oil temp of 130 is high 105 to 110 is the benchmark usually. Oil temp does start to creep up when it needs changing.

I assume it's a water-to-oil heat exchanger.

On the head gasket - did you have the head skimmed and the gasket replaced with a genuine peugeot one? a tiny crack between a water and oil way may not have been spotted/cured?

Occasionally we get head gasket failures on here but usually it's the water side and usually it follows some kind of owner abuse like running it low on water etc. your problem is new to me

When you flushed did you remove the thermostat? Maybe you should remove the rad and flush that forwards/backflow etc?

Let us know how you get on.

[lancer]

Yeah got the head tested and skimmed and it came back as being ok.

Removed thermosat and flushed fowards and backwards ok. What i find strange is that the coolant that came out when removing oil cooler was clear of any oil i know oil floats on water but i thought i still would have seen some discoloration but it was still the same pale blue from the coolant.

[Doggy]

@ doggy your oil temp of 130 is high 105 to 110 is the benchmark usually. Oil temp does start to creep up when it needs changing.

Correction - mine sits 1 division above the 90, (which is probably nearer to 110 than anything, but it's a bit vague).

[colpug]

Hi, sorry to bump an old thread, but has the op solved the problem? I have the chance of a 1.9 td r reg 406 with this fault, oil getting into coolent. The owner has bypassed th oil cooler and flushed the coolent but its still doing it, he thinks it the head gasket, but i`m not so sure. Any advice would be appresiated thanks Col.