Head gasket or egr cooler?

[Enjay999]

Got a 2007 2L tdi single cam PD lump. Been having issue with the pressure pushing coolant out the cap. Tonight I was able to get a pressure tester hooked up and went for a spin. As soon as I hit a big hill and gave it plenty of right foot the pressure rose, eventually went over 20psi!

Now my thinking is the head might be lifting a touch under boost but someone suggested it could be the egr cooler which I'm reluctant to think possible. Only coolant I seem to lose is from the cap itself.

My experience of a cracked head caused constant pressure and that was without a turbo in a petrol car with less compression so I'm kinda ruling that out.

Anyone have any other input?

Cheers

[johnnyroper]

My guess is head gasket but sure fire way to eliminate the egr cooler is link the 2 coolant hoses temporarily. Not too familiar with 2.0 pd lump but would assume itââ,¬â,,¢s much same as the 1.9 where you can use a bit of copper pipe to join them. Canââ,¬â,,¢t recall if it was 15 or 22mm I used though.

[Enjay999]

Yeh 22mm and you can do it but I think I'd have to chop a pipe as it tends to kink one a bit much. I've been in about the cooling system for other issues already lol.

Just wondering if it's possible the egr cooler could actually create the pressure and only under load. I'm only losing a bit of coolant out the cap too, no mysterious disappearing.

[johnnyroper]

The egr cooler could cause it much like combustion gas passing through a head gasket. When my old 1.9 had gasket issues I didnââ,¬â,,¢t lose coolant other than when it blew out the cap.

Disconnect one of the EGR pipes from cooler and pressure test the cooling system,if cooler is at fault you should get a trace of coolant leaking in to it.
Under load is classic head gasket issues though as the combustion gas escape is greater the harder you push the engine.

[Enjay999]

Today I bypassed the egr cooler then tomorrow I'll see how it goes, when filtering the coolant I'd removed there was traces of a soot like substance in the filter after.

I hadn't realised what kind of pressures you can get in an exhaust manifold of a turbo diesel either, looked it up today and it made sense. Definitely sounds possible now.

Anyway see what happens tomorrow then I'll take it from there.

[Enjay999]

Head gasket it is, still to much pressure in the system. gasket and bolts are ordered and I should be good to go this weekend weather depending. Cheers