944 Turbo Smoke

[Duncan189]

Just treated my self to a 994t after having a couple before. Very nice well maintained with 120k on the clock. smell a bit rich when started up from cold but after going for my Sunday burn i notice smoke after i have slowed down in 3rd or 4th gear after a heavy foot then pull away - white / grey smoke is noticeable from the rear, doesn't smoke when you start up or when general driving. If i remember rightly this is a system of ring worn or can any one else advise

[benjj]

That sounds like a classic example of worn valve stem seals.

They say the best test is to find a long down hill road, stick it in 4th and let it roll down on tick-over. At the bottom give it a healthy boot of loud pedal (still in 4th) and if you shoot out a load of oily st then your seals are fubar.

[Cheburator mk2]

benjj said:

That sounds like a classic example of worn valve stem seals.

They say the best test is to find a long down hill road, stick it in 4th and let it roll down on tick-over. At the bottom give it a healthy boot of loud pedal (still in 4th) and if you shoot out a load of oily st then your seals are fubar.

Almost 100% correct. Also, when we rebuilt mine, the valve guides were gone too. 105k engine with good history. The valves are heavy and the guides are short, hence the wear. Just bear in mind that you may see another nasty when you lift the head off. Mine smoked occasionally, diagnosed gone guides and seals, lifted the head off, only to see cylinder N4 scored too. On a road engine, would have put back together, without bothering with the bottom end, but on a race engine decided to sleeve and start afresh.

[Duncan189]

Thanks that's what it does smoke come out when you slow down in 4th all the way down the accelerate smoke "blue comes out" is this not more rings or do these cars suffer more top end. When its cold - been standing - first thing in morning there is small amount of blue smoke ( as much as I can see from the drivers seat ) pointing towards he valve guide.

[thegoose]

A friend had a very good 944T that was running fine, no smoke etc, but he wanted Wayne (Chipwizards) to remap it to liberate a few more horses. The first thing Wayne asked was "has the head gasket been changed" - not knowing if it had or not, he took it to Unit 11 to be done - this resulted in the worn valve guides they found being replaced and a full head recon. He was amazed how much more responsive the car was afterwards, particularly lower down the rev range. Of course, it was even quicker after a new boost valve thingummyjig was fitted and Wayne worked his magic for a couple of hours

I'd recommend getting it checked over with a view to having the head reconditioned, I think you'll be pleased with the result.

[FraMac]

Recently had Unit 11 do a compression test on my 968. Happy days.

[IMIA]

thegoose said:

A friend had a very good 944T that was running fine, no smoke etc, but he wanted Wayne (Chipwizards) to remap it to liberate a few more horses. The first thing Wayne asked was "has the head gasket been changed" - not knowing if it had or not, he took it to Unit 11 to be done - this resulted in the worn valve guides they found being replaced and a full head recon. He was amazed how much more responsive the car was afterwards, particularly lower down the rev range. Of course, it was even quicker after a new boost valve thingummyjig was fitted and Wayne worked his magic for a couple of hours

I'd recommend getting it checked over with a view to having the head reconditioned, I think you'll be pleased with the result.

^^^ this - very good advice.

[Duncan189]

This is all great advise I have a local Porsche man who is going to have it for a couple of days to do various test cold and when its hot. Does any one have any ball park figures for a top end overall

[Cheburator mk2]

Duncan189 said:

This is all great advise I have a local Porsche man who is going to have it for a couple of days to do various test cold and when its hot. Does any one have any ball park figures for a top end overall

How long is a piece of string? I was quoted £200+ VAT to skim the head and have the valve seals replaced with a 2 day turnaround time. However, it could escalate quickly - valve guides are about £8 each, then you need them pressed in, also if the guides are really shot, the actual valves will be gone too. Intake valves are cheap, but the sodium filled exhaust valves can make you weep. May as well change them for standard steel ones - have not heard of failures yet. All in, you may be looking at £500+ if you need everything...

Of course you have to add the labor needed to take the head off and put it back on, hence your overall costs could well run to £1500. As the goose states further down below, if you are going to do it, do it properly. Go with your eyes open and be prepared that it may need more cash thrown at it than just what is needed for a skim and valve seals job.

Edited by Cheburator mk2 on Wednesday 4th March 09:18

[Duncan189]

That's better that I ecpected do the Pistons or rings generally fail or is it more too end as mine pull well has had supper chip fitted 2004 goes veryvery got and ason vantage v8, friend car which I keep at mine and drove that after 944 t and it's not or doesn't feel as much fun or as fast

[thegoose]

I don't mean to sound the smart-arse but re-read my previous post re. the right order to do things regarding chips/remaps etc

The job I referred to did escalate so that everything was done properly and thoroughly (he always makes sure everything is done right, especially in this case as he wanted to then increase the power) and it came to I think something like £1300-1400 and that's by a very efficient garage with a very competitive labour rate. That may have included other non-related bits and pieces though, I don't recall.

After it was all done the car made easily over300bhp on the dyno but was tuned back from that slightly but with an advantage in the torque - such is the advantage in having a proper tailored live remap by an expert.

Most importantly of course, it went very well indeed and was 100% reliable.