Oil pressure relief valve

[Miss Marple]

Hi all. I need a bit of advice please! Whilst doing an oil change on our 1.9 petrol watercooled engine, we undid the oil pressure relief valve rather than the sump nut (total novices but ya gotta start somewhere eh?). Anyway, the whole lot fell out, comprising of a nut, washer, spring and what looks like a small piston. Now the piston has a larger end and a smaller end, both the same diameter. Can anyone advise which way up the piston should go, and also if there is anything else we should know before re-assembling it and blowing up the engine?

[Grun]

Miss Marple,

'Small end' uppermost. ie the groove nearer the top of engine, followed by the spring, then washer and cap.
Make sure it is all clean, the washer should just be a sealing ring to prevent oil leakage from the blanking cap.

Mike

[Miss Marple]

Thanks for the advice. We fitted it all back together, and it leaked like a goodun, so we bought a new sealing ring and its still leaking. What are we doing wrong?

[Grun]

Thanks for the advice. We fitted it all back together, and it leaked like a goodun, so we bought a new sealing ring and its still leaking. What are we doing wrong?

Dunno, can't see from here Here is the best image I can muster.

Is the spring coil bound, is the sealing washer pinched correctly, are the mating faces damaged? Not a lot could go wrong I would have thought.

[IMG:81:226]http://i150.photobucket.com/albums/s88/ ... fvalve.jpg[/img]

Mike

[Miss Marple]

This forum is great for advice. Brilliant image. It appears we were just being a bit too gentle with tightening it! Dur. We took it to a VW friend who gave it an experienced bit of muscle and hey presto. No leak. Thanks for your help. Oil change should be a doddle next time!

[Grun]

Miss Marple,
Glad to hear that you're sorted.
Mike