RE: Valve guides

[Paul.Heneghan@bbc.co.uk (Heneghan,Paul)]

>From: Sam Massey
>To: Paul.Heneghan@bbc.co.uk
>Cc: sam.massey@asa.co.uk; quattro@coimbra.ans.net
>Subject: Valve guides
>Date: 18 June 1996 14:13
>
>Paul,
>
>In a recent mail to your list, you mentioned that the valve guides 
 wear are part and >parcel of owning an Audi, is this because you have 
 had a recent experience with >this part of the car? The reason I am 
 asking is because (whilst I hadn't noticed) >someone following my car 
 informed me that it was smoking a bit on pulling away, >accelerating 
 hard etc.. The car 85 80 4cylinder, has done 80,000 miles..and I was 
 >wondering if there were any other symptons to check for...and what is 
 the damage >$$ in replacing the guides.
>
>Cheers 
>
>Sam

Hello Sam.

I and my family have owned a Jetta, two Passats, and 80quattro and an 
 Avant in the last 10 years.  With the exception of the Avant, they all 
 burned oil through the valve guides.  The Avant is an automatic with a 
 perfect service history, so even though it has 135,000 miles, it has 
 probably had an easy life.

On the 80quattro, I first noticed it at about 90,000 miles.  I had been 
 driving at 110 in Germany for an hour or so.  I had to slow down, 
 which I did by lifting off the accelerator.  I noticed lots of smoke 
 out the rear window.  Then when I accelerated again, I got another 
 huge blast of smoke out the exhaust.  I am not sure how much oil I am 
 burning, because I also have a leak, but at the moment, I put in a 
 couple of pints every 500 miles or so.

I don't know how much it would cost to get it fixed.  I have heard from 
 a number of sources that the valve guides wear and new ones need to be 
 pressed in.  Also there is an oil seal on each valve, but I don't 
 think you are supposed to replace those without replacing the guides 
 as well (false economy).  Usually, whenever someone takes a head off, 
 they end up doing everything - replacing valves, guides and seals, cam 
 bearings etc.  This runs into a couple of hundred pounds - look how 
 much recon heads cost in the magazines.

You said that your car smoked on hard acceleration.  This could be 
 piston ring or cylinder wear.  Smoking on the overrun (followed by a 
 short blast as you start accelerating again) is a sign of valve guide wear.

Do a dry and wet compression test - this will show up serious piston 
 ring or cylinder wear, but if the two figures are the same, then it's 
 your valve guides.

Hope that makes sense.

Paul
paul.heneghan@bbc.co.uk