924Board.org

[B]

hi everyone,
I have had smoke (white-ish i believe) coming from the exhaust for quite a while. After driving the car for a while it will eventually dissipate - however it does take a while and can accumulate quite a bit. I have also noticed oil coming from the back of the motor - possibly the distributor area. This - of course - is dripping on the exhaust causing even more smoke. really cool if you are looking for the smoke machine affect - not so much if you are in the garage with your 924.
I am wondering about the valve stem seals - are these very difficult to replace? after reading up on it - it seems like a very involved process. Would this job be easier with the head in or out of the car? I found a gasket set for around $76 (is that reasonable?)
Also, are there any special tools needed for this?
sorry so many questions -

Any help would be greatly appreciated!
B
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1979 924 n/a
BAE turbo
5-speed snailshell

[ideola]

White-ish smoke would be indicative of a failing head gasket. Opportune time to pull the head and do a complete top end rebuild.
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erstwhile owner of just about every 924 variant ever made

[Smoothie]

First know for sure what's burning -
White, sweetish smelling smoke is coolant burning.
Bluish, greyish, sometimes mistaken for white smoke is oil burning.
Black smoke is fuel and an overly-rich a:f mix.

If you are burning oil and the valve seals are the cause, you should be able to make it smoke. Try this at a point after driving a while when you feel that the smoking has dissipated -
Increase manifold vacuum - do this by engine-braking (using the engine to slow the vehicle. Downshift and release the clutch pedal.) The increased vacuum will pull more oil down the valve stems past the seals if they're leaky. Then rev the engine. If you see a bunch of smoke, then it's safe to conclude that the valve stem seals need replacement.
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"..it's made in Germany. You know the Germans always make good stuff."


'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox

[924RACR]

+1 - do a head gasket job, you'll clean up all your problems (leaks) at once, including valve stem seals. Also you should re-lap the valves (as well as cleaning off the deposits) for better sealing, while you're in there - easy and cheap for tools to do by hand.

You will need to borrow/rent a valve spring compressor, but those are generally available at most any parts shop.
_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

[!tom]

[ideola]

Here is the right tool for the job, but I doubt you can rent one locally.




After borrowing Vaughan's and seeing how easy it was to use, this is the only spring compressor I will spend money on. $142.50 on evilBay.
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erstwhile owner of just about every 924 variant ever made

[924RACR]

Actually, that one is ONLY for doing the valve stem seals with the head still installed on the engine. It's a VW tool, in fact.

In your case, since you should do a head gasket job IMO, you want a different type of compressor.

What we've done in the past, and I still use, is to take a small piece of pipe or EMT conduit maybe 2-3" long and place it between the top of the spring and the spring compressor jaws; this improves the geometry and prevents damage to the head. Downside is now you have to work through that pipe to remove/install the keepers, but a little patience, a small pickup magnet, and some picks and you'll get it.
_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

[B]

thanks everyone
Smoothie I will try that to see if it gives me an idea about the kind of smoke that I am seeing - plus it will give me a chance to see how the new shocks feel.

924RACR- if it does come to changing the head gasket, do you know what other compressor would be needed? I found several compressors one in JCWhitney for VW ( www.jcwhitney.com ) item # day818224 - but it does not look anything like the tool ideola showed a picture of (thanks very much ideola for those too). is it any easier to change the valve stem seals out of the car as opposed to leaving the head in?

thanks again everyone
_________________
1979 924 n/a
BAE turbo
5-speed snailshell

[Rasta Monsta]

I also have an article from Euro Car about this procedure. . .I can email it to you if you PM me.
_________________
Toofah King Bad

• WeiBe (1987 924S 2.5t) - 931 S3

[B]

Rasta-
thanks - pm sent
B
_________________
1979 924 n/a
BAE turbo
5-speed snailshell

[B]

924RACR
- not to ask a dumb question but what is lapping/re-lapping the valves?
thanks
B
_________________
1979 924 n/a
BAE turbo
5-speed snailshell

[Smoothie]

[924RACR]

There are no dumb questions when it comes to this stuff! Well, maybe - we might have to check with Timstar on that one...

Lapping the valves is also referred to as grinding the valves, where you rub the valves against the valve seats with a grinding or rubbing compound (like toothpaste, or rubbing compound for paint) to get full contact all the way around. You can buy a valve hand lapping tool for about $5 at your local parts store, plus another $5 or so for valve grinding compound.

The type of spring compressor we were talking about is the C-type, shaped like a giant C-clamp - see item ZX510204W

It is a bit easier to change the valve stem seals once the head's off, but of course there's the slight matter of all the work required to remove the head...
_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

[Mike924]

Hey, Smoothie, you knew B was going to ask that question about valve lapping when you did your Jeep. That's why you took the picture, isn't it?

BTW, what's that interesting-looking gadget next the pot of grinding paste in the photo?

(Sorry for the number of edits - usual keyboard dyslexia...)
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1985 Porsche 924 'Lux', Kalahari Beige (my ex)
1993 Porsche 968 Coupe, Midnight Blue, 6 spd

'There is no substitute for a little grease under your fingernails.' - Chrenan, 924board.org

[Rich H]

Looks like a picture on the magazine he is using to protect the kitchen table
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1994 Lotus Esprit S4 - Work in progress...
1980 Porsche 924 S2 DITC Turbo - Original spec
1978 Homo-Sapiens - Tired spec
1953 Landrover S1 - Pensioner Spec