dirtydevin

My car has been running rough at low rpm, especially in the morning when I first run the car. So I did a tune-up with plugs, cap, rotor, wires and when taking out the #8 spark plug it was dripping with fresh clean oil. I think the vavle stem seals are leaking oil into the cylinder while the car sits and then it has to burn off, or is fouling the plug when I run it in the morning.

SO, can you do the valve stem seals on a 16v car with the heads still on the block in the car? What type of valve spring compressor works best?

If not and I have to pull the heads or engine, what performance work is worth doing while I am at it. I would like to upgrade to the 85 exhaust manifolds, maybe some head work, 79 cams, or 944 heads? What would be the best bang for the buck as far as these things go?

dirtydevin

Sorry, forgot to mention the car is a 1983 928s 5spd us spec.

michael j wright

Much eaiser to pull engine first. It takes longer to pull cam covers off than it does to pull the engine to get to the heads. Yes you can change the seals without pulling the heads, but it takes creative ways to get the springs off and is a PITA to do. Better to pull heads and get them checked at a machine shop at the same time. Also while its out you can clean up everything, change pan gasket to the silicon style and also do the motor mounts. As far as performance upgrades and such, someone else will have to chime in on that.
Mike

karl ruiter

Best bang for the buck would probably be a set of Euro S heads, if you can find them. I don't think there is much that is simple or small that you can do that will help much.

dirtydevin

I had a feeling I would see the "pita" listed in a response to this problem. How long does it usually take to pull the engine on these cars?

Humm, anyone selling euro heads and intake setup?

Mrmerlin

Ahhh Wait... I am not sure of your description and where this oil was..
Please note it is completely possible that your cam tower is leaking and the oil is running into the plug well of #8

was the plug wet on its shank or was the center electrode dripping with oil

dirtydevin

I considered that it may have been oil sitting in plug well but as I didn't really look before removing the spark plug, but it definately appeared dry in the well when I looked after removing the plug and the top of the plug was not covered in oil. I will check after driving to work and back though to be sure.

Brett928S2

Hi

As a general mechanical principle its a damn site faster to change a set of stem seals in situ (assuming they can be done in situ) than to remove a whole engine then have to do them anyway....

The difference is hours of labour versus days of labour.....

All the best Brett

dirtydevin

I admit it is a bit on the slacker side, but I would probably just do the #8 cylinder to save time and effort as it is the only cylinder showing any signs of problems.

I just changed all the valve springs with heads on my ls 6.0 engine in about 30 minutes, but it sure won't be the case with the 928 engine stuffed in these cars.

123quattro

Sounds to me like you've never had your 928 engine apart... Pull the engine.

Bart-Jan

If your spark plug is dripping of engine oil, I guess there's something wrong much worse than a leaking valve stem seal... I'd check compression first, If I were you. You might end up doing a lot of work on the engine while it is in, whereas you might need to do a lot of extra work afterwards anyway if something else was the problem.