Weird temperture behaviour 2.5 v6

[Pruts3r]

Originally Posted by T-Cut

Unlikely. The header tank cap as a safety valve the relieves the slightest vacuum. I'd look a little more closely into possible pressure release.

TC

Okay, i dont really know what you mean with that? Check if the cap is faulty?
And what does the presure being released when removing the cap on a cold engine tell me?

[Pruts3r]

Originally Posted by SD1too

Merijn,
...

That's what I would do in your position.

Okay, i did find out that he didnt take off the inletmanifold. But still worth a shot right?

Originally Posted by SD1too

I would say not. Much more likely to be those inlet manifold gaskets.

Okay but what about the mayo that keeps building up? Can that too be from ILMgaskets?

[SD1too]

Originally Posted by Pruts3r

Okay, i did find out that he didnt take off the inletmanifold. But still worth a shot right?

Yes. Several owners have found their inlet manifold gaskets to be in poor condition. Both manifolds have coolant connections so if the gasket is not sealing effectively you are likely to get all sorts of upredictable pressure and level effects which can be misinterpreted as head gasket failure.

Okay but what about the mayo that keeps building up? Can that too be from ILMgaskets?

The usual cause of mayonnaise in the KV6 engine is a failed oil cooler.

Simon

[kaiser]

The inlet manifold gaskets can easily cause mayo in the engine.
The water passage runs in all corners of the inlet manifolds, front and back, very close to the inlet for all corner cylinders.
The water pressure is positive and the inlet pressure negative, creating a solid suck towards the inlet valves.
Water sucked in this way, will largely burn off, but part of it will find its way into the oil and cause mayo under the oil filler cap, even on a warm engine.

It is well worth the effort to check/replace these.
A trick, give them a solid layer of silver paint each side before fitment. Normal garden gate variety will be OK.
When tightening, do it gently and in stages, but make sure it is firm. Re-torque after bedding in, if you ask me.

Good luck and take pics!!

[kaiser]

Shooot!!

Got past post 5000!! and did not even notice it!

Must learn to hold my tongue!

Pat on back! tsk tsk.

[Pruts3r]

Okay guys! Thnx again. Inlet M gaskets first then and is mayo keeps comming up then the oil cooler. A trouble free 75 would be great. Will get there eventually.... I refuse to give up!

[T-Cut]

Originally Posted by Pruts3r

Okay, i dont really know what you mean with that? Check if the cap is faulty?

The cap is designed to prevent the cooling system generating a vacuum by cooling down. No harm in replacing the cap if there's any doubt about it.

And what does the presure being released when removing the cap on a cold engine tell me?

That it's been pressurised above normal atmospheric pressure. There should be no pressure on the cold system.

TC

[Pruts3r]

Originally Posted by T-Cut

That it's been pressurised above normal atmospheric pressure. There should be no pressure on the cold system.

TC

And that pointe towards a faulty cap or something else?

[Pruts3r]

Update

Took the car for a half an hour drive yesterday and drove gentle and temperature was between 95 and a 100 constantly while drivig between 50 and 110 kmh.

When standing still temp rises quickly too 100 (fan kicks in then) and keeps rising to 104 and stays there. Fan keeps spinning but cant bring temp down. When moving again slowly drops between 97 and 100 again.

Also when driving 50km for exemple with low revs temp rises to 100.
When reving more (for example lock autobox in 3) while driving about 50km temp keeps lower.

More rpm = cooler engine

[kaiser]

There can be two explanations for what you see.
1. Too little water in the system.
2. Ineffective water pump, worn impeller loose on shaft.

I think you are loosing water!