Oil smoke

[lawsi]

Hi, Some opinion/experience sought; I've had a couple of large puffs of smoke under hard accelleration above 4500rpm recently (I don't do this very often!). None when revved to the same level at standstill - is this just old engine stuff, valve stem seal wear or something more important - some previosu mention of this being related to the bore?

All opinions, help with diagnosis etc much appreciated.

 

[Peter Empson]

If you're not revving the car above 4.5k very often then it might just be crud being cleared out. If it gets less the second or third time you take it to higher revs then that should be a reasonable indicator I'd have thought. Personally when the cars warm I believe in making use of the whole rev range whenever appropriate, that's most journeys []

 

[PSH]

what colour smoke?
when was oil last changed and with what oil?
Valve stem seal ware shows itself when starting the car after it's been left standing over night not when you drive it hard.
There are many reasons for smoke from a 944 , most have nothing to do with bore wear however.
Check breather system as this can cause a 944 to smoke, more so on a turbo though.
Check the plugs to see if any signs of problems there, if you have a compression gauge then would be good idea to do a compression test too, although to be sure you would need to do a leak down test.
Also check for any air leaks around inlet/throttle body/j-boot.
Lastly has the car used more than normal oil recently.

Hope this helps a little, with a little bit more info it may help some of us here to give a more informed diagnosis.


Pete

 

[dann944]

when i bought my car it had been sitting for a good long while and hadn't been serviced i had this problem took it to Jon Mitchell and they diagnosed an old fuel filter full of crap, managed to somehow get thru the engine and i had a few big clouds of black/blue smoke at about 5/6000 revs, it has since been changed, and this has gone away!

Dann

 

[PSH]

Personally when the cars warm I believe in making use of the whole rev range whenever appropriate, that's most journeys

haha.. a man of my own heart... nice one Pete...[][][]

 

[lawsi]

Last oil change & oil filter a couple of thousand miles ago (inc. full flush beforehand first) with 5w/40.

All airways are well sealed.

Plugs are clean

Oil use is quite variable from some to a lot but correlates to driving enthusiasm - it's definitely more than seems typical from comments on here though

So on the basis I may have been being too too tender, I went out and er, repeatedly explored the power band - oil smoke above 4500 faded away as the smiles grew []

Obviously need to do this more often and generally chill out about the quirks and character of the car all of which grow on me more and more as the months pass...[] (cue for mechanical disaster no doubt!)

Thanks for all your replies - Iain

 

[PSH]

cue for mechanical disaster no doubt!

I doubt it , these cars like to be driven hard , very hard...it's a Porsche not a ferrari....[8D][8D]

Happy to hear your having fun with her , keep it up..[]


Pete

 

[Peter Empson]

ORIGINAL: lawsi

So on the basis I may have been being too too tender, I went out and er, repeatedly explored the power band - oil  smoke above 4500 faded away as the smiles grew []

Result! []

Not in a 944, but I remember blacking out most of the A41 when we gave a new Merc Diesel a dose of the right pedal for the first time, the exhaust was so full of soot you really couldn't see a thing behind [] It ran much better afterwards though.