compression test advice

[16v Matt]

Hmm, exactly the same as mine. Think i'll get her booked in :'(

[Deefadog]

Can't get mine done until pay day, so let me know how it goes!, pm me if you want!

cheers

[frankerooney]

I've got a slightly iffy valve seal on my Golf and it shows up when the car has been sitting overnight as a cloud (!) of blue smoke when the car is first started. It should also show as the car decelerates and you blip the throttle back on - apparently the oil is forced to the top end of the engine when slowing down and you blip the throttle and any oil getting past the seals is burnt. Not sure about it showing just at idle though?!
Do you know what the oil pressure is when the car is hot? Just wondering if it could be forcing oil past the head gasket into the cylinders from the oil galleries only when the engine is warm - thermal expansion..?

[16v Matt]

D'oh! Now i'm really worried!   Say for example the oil pressue was too high(i have absoloutly no idea how to check this!) what sort of things could be causing it?  

Sorry to hijack your thread Deefa!

[Deefadog]

Go for it mate it apllies to me aswell

[frankerooney]

Oops. Was just thinking out loud really. I was thinking that the classic symptoms of valve seals show up more on deceleration than at idle when the vacuum is higher (to my knowledge anyway).
Saying that the powdery black stuff suggests oil being burnt, so it's either valve seals, blocked crank case breather or something else, and I was wondering what the something else might be.
Cylinder pressure finding it's way into the oil system would probably force oil out of your dipstick hole or make a hissing noise when the stick is removed.
 You sure that your PCV valve (black mushroom thing) is working ok? That being faulty would probably cause your symptoms aswell.
I think you'll find it's most likely to be valve seals.

[16v Matt]

  how can we check  the pcv valve? & is it on or very close to the airbox or am i way out??


Cheers mate.

[Deefadog]

Yes where is the PCV valve and how do we check it?

Looks like me and you matt have about the same knowledge, but it is fun in a sad way!

[16v Matt]

Everyday's a school day deefa!! (for me anyway)

[frankerooney]

I expect there's a PCV on the 16v, but I don't know what it's like. Ignore what I said about mushroom thing-think it's only that shape for 8v's. Is there a rocker cover plastic shield on 16v's? On the 8v if you take it off, the oil can get into the breather system..