Help! Smoke or Condensation

I hope there is somebody out there who can try to solve and issue with my Porsche 996 3.4 (2001 with 42,000m) which has had the following strange symptoms to a lesser a greater degree over the last year.. Here's what the issue is and the symptoms. When I drive the car hard (motorway etc, etc) it runs absolutely fine although sometimes (not always) I have noted that at high reves and speed I get a plume of what appears to be (white) smoke from the exhaust... and not a small amount. The car will continue to run fine for the rest of the day... The next day (after running the car hard) when the car is parked up overnight and I start it in the morning I get a HUGE amount of white smoke or condensation or mixture or both... this covers the entire street!!!!!! Whenever I don't drive the car hard (normal street driving) I do not get this problem the next morning... no smoke/condensation. Car dives fine. I took the car to Porsche who did a quick (15 min) ramp check and they could find nothing wrong... the tech took it out for a test drive and drove it hard and said its fine.... 'a very tight tidy car" ...... I took it away feeling curious but fairly settled and happy...... The next morning...huge plumes of smoke/condensation because it had been driven hard...(by the tech). I took the car to JZM who diagnosed as 'Oil separators"... which were changed and was informed the problem will now be gone.. they had test driven it after the work...... In fact the morning I picked up the car from them.... HUGE plumes of smoke/condensation again ... I was told its probably the residue oil which could not be cleaned out... it will gradually disappear after a few days.... Then .... Both back exhaust boxes failed... the internal bafflers had rotted inside the boxes.... These were both replaced (by JMZ).. I started thinking about the relevance of this and thinking about what looks like a huge amount of white condensation coming from the exhaust.... Thinking that water must be escaping from the engine into the exhaust... when driven hard... then sitting in the exhaust boxes.. When the car is started in the morning... this sitting water is expelled as a huge amount of condensation (hence the old boxes went rotten)... could this be the problem?..... That would surely mean a head gasket has gone.... If that was the case.... my running temp would go high!!! It doesn't really... slightly higher when I sit in traffic... but it drops again once I'm on the move...... I checked the water header tank... slightly under the 'max" fill line...... so its not losing water.... So what can this be!!!! Is it smoke/engine issue?...is it condensation (even in the summer) and a water/gasket issue? I'm now actually scared to ever drive this car over 60mph and never now put my foot down.... There seems little point in owning this car if I can use its power occasionally... Nobody seems to know what this problem is... Its been into Porsche & JZM and still the problem persists ... I'm thinking of booking the car back into JZM and I would like anybody who has any ideas or suggestions so I can put it to them... Thanks for your help... Stuart

Hi Stuart, don't know if you've done a search on here but 'Peach' had/has something similar. Check http://www.911uk.com/viewtopic.php?t=35644&highlight=smoke You may want to PM him and see if it's the same problem...

Thanks Thanks Stuart, I'll pm him now.... He had his oil separators changed and his last post implied it sort of cured the issue.... I had my oil separators changes only 2-3 months ago.... In fact as mentioned in my post... it billowed out white smoke the day I picked it up so its a bit disconcerting. I'll keep this post updated for those that are interested... Thanks Stuart (Great name that! best on here in my opinion). Stuart.

Hi Blob! I had a similar issue with mine but it was defo blue smoke after giving it a good but respectful "thrash" every now and again. Strasse in Leeds changed the oil seperators and have had it in and out four or five times trying to diagnose the cause and even though they have witnessed it themselves we arrived at a point where we gave up trying to find anything that would cause it!! Apparently the car and engine is perfectly fine and there is nothing wrong - it just billows out blue smoke every once in a while and Strasse reckon it could be a symtom of a tiptronic car. The car runs fine, sounds fine, etc etc so I've just learnt to live with it and not thrash it whilst cornering ! :nooo:

Well I think Strasse are talking b*ll*cks about it being a function of a tip car. What possible difference could the transmission make? Does it use much oil? My money's on Stuart's oil separator. I know it's been changed, but I've seen a couple of cars where it's gone, and it's like an old-fashioned thick London fog. Exactly as you describe. Sometimes it takes a day or two to disappear completely, but not a couple of months. I am assuming, of course, that the white smog is coming from BOTH exhausts. Therefore it's something common to both banks. Unlikely to be a head gasket IMO. I think the exhaust thing is coincidence, and am surprised to hear they rotted inside. Baffles often come loose and rattle though.

Howdy - sorry for the late response; moving house at the mo and v limited internet access. My tuppence worth is that it is still very much to do with the oil separator and you have nothing to worry about. However, I would suggest that you take it back to JZM or just pick up the phone and call them. When I did the same I had a long chat with a couple of the engineers who were great and really put my mind at rest - I was all for getting it back in the workshop and they told me "not to waste my money - take it for a good thrash and see what happens. If it's not drinking lots of water or oil or making any nasty noises (and works 99% of the time) then you have nothing to worry about". And TBH whilst, in a nutshell, they told me that it's a design flaw so there's nothing you can do about it they seem to have been right. Nevertheless, to see if it's similar to the problems I was having can you tell me the following: 1 - Is the smoke is getting less thick now or is it pretty much the same? (mine only really cleared after a trip to the ring) 2 - Are the number of occasions it happens getting less or staying the same? (prior to going to the ring mine did it once or twice gradually getting better over time then it stopped [although it did repeat on going round the ring - so maybe you're driving it REALLY hard on the road ]) 3 - Can you predict when it happens? e.g. is it always on the same road/ does it happen on left and right turns or does it only happen on steep hilly sections etc? 4 - Do you ever see smoke out the back when you're driving along? My theory is that it's the same problem I had which has now been fixed however, you've just got a lot of residual oil left in the plenum which you're only shifting in small amounts. The only way to shift it is to burn it off (or perhaps strip the engine down and soak it up with something....not ideal) so theoretically you should be able to do this with a few solid spirited drives. However, if you're continually getting the symptoms even with an averagely warm drive then perhaps there is either A) more residual oil left than I had or B) something else causing the symptoms. Sorry I'm not able to be more definite, but if it's any consolation I know exactly the way you're feeling. The shame I had starting my car up every time I wanted to go for a lap of the ring (complete with car park engulfing smokescreen) was immense and it took quite a while before I stopped caring. After that it just amused me to see winces and looks of horror as I set off for another lap!

smoking Thanks everybody for your input... Its now booked to go back into JZM this week, so I am hopeful it will get sorted. The smoke only ever happens the morning after I have driven the car hard... but I only mean 'road" hard... (Motorway... quick overtake etc etc) definitely not as hard as going round the Nuremberg. The next morning I switch on and it's a complete London fog (as somebody else so accurately described) to the degree that not only is it an embarrassment but I am get grunts and raised eyebrows of disapproval from my neighbours... Of late I try to drive the car around like an old ford fiesta so as not to not cause the issue the next morning... Taking note of Richard's comment... I checked this morning and it is definitely billowing out of BOTH exhausts, therefore it's something common to both banks. Which I think may be good news if ever there could be good news for this type of thing..... but it looks so, so bad when you switch on. So its off too JZM.. and I am suspecting it need to get those oil separators sorted AGAIN... as it was only done a couple of months ago and the issue has got progressively worse since then.. I'll post here the outcome for those that are interested Stuart

Just a point of interest - there is only one oil separator which causes this problem, which is a plastic canister mounted on the top of the engine at the front. It splits internally and allows oil mist into the inlet. There are two other air-oil separators, but they are in the crankcase. Edit: Which begs the question, did they change the ones in the crankcase? This can be done with the engine in place, and is, in fact, an easier job than the one on top of the engine. Can you get the part number from the invoice, and I'll look it up.

Part No Hi Richard The part No given on the invoice is; 99610702354 OIL SEPARATOR Thanks for your continued help. Stuart

Yes, that's the right one - on top of the engine. Maybe Peach is right, and it's taking a long time to clear the residue. I hope it's as simple as that.

Oil Separator Thanks Richard, The work was actually carried out in May and I use the car daily (aprox 20m a day + a trip to France). I'm not sure how long this residue should take to clear but that seems like a fair few miles (aprox 2,000m) and the frequency and amount of smoke is getting worse.... Thanks, Stuart

Re: Oil Separator Hmm this is slightly more perplexing - getting worse and more frequently doesn't sound right. There is the possibility that it wasn't fixed correctly or it was replaced with a defunct part - so again I would speak with the guys at JZM as they've always been very helpful. However, the distance covered won't necessarily burn off the excess if it's sat in the plenum (as I was informed my residual was) as this is a u or v shaped channel in between the cylinder banks(no doubt someone will be along to correct my chronic misunderstanding soon enough). Assuming this to be correct it will take some heavy cornering (or banking) to displace this residual as opposed to simple daily driving. So Q1 - does it always smoke on start up regardless or just after a thrashing? Q2 - if only after a thrashing - are you able to park it on a steep hill sideways after a GENTLE run to see if it smokes then? Q3 - if it's getting worse and more frequent are you actually using any more oil than usual? One other point of note though I was told that one of the culprits of causing the separator to fail is a lot of short journeys. Whilst 20m isn't 2 miles down the shops and back it also isn't a massive distance to cover each day as it takes the car about that to fully fully come up to temp (so I am led to believe). This could be compounded if you're giving it a good thrashing within that 10m (assuming it's 10m each way).... Any of this helping?!

Smoking Thanks Peach, OK.... Q1 - It only smokes after a thrashing. Never smokes after a gentle drive. Q2 - Seems to make no difference how its parked (I live on a slight hill), only after a thrashing will it smoke so no matter where the oil settles after parking up for the night. Q3 - The usage of oil did worry me some time back so I checked it and over the last 4 months I have only put in 1Lt of oil.... I'm not sure how accurate the oil indicator is but on flat(ish) ground it always shows at least mid to top bars. Yes... the short journey issue has been pointed out before but I dont recall ever thrashing it during the short (under full temp) journey.... usually sitting in traffic!! Its into JZM tomorrow... so I will discuss with them all possibilities and get them to check out the oil separator as its definately top of the list. Thanks again... Stuart

Re: Oil Separator Going by the temp gauge, my car is warm 85-90C after about 3 miles driving at about 30/50mph. 20mins[10miles] to warm an engine seems a long time TB

Re: Oil Separator Doesn't it just However, this was the very same conversation I had with the technician who assured me that whilst the temp guage records that the water is up to temp it takes far longer for the whole car to be up to temp. Whilst he didn't say you shouldn't drive it hard till after 20 mins it would be advisable to leave it that long before really wringing it out. Q1 - sounds in line with residual or faulty separator Q2 - can you park it sideways on this hill overnight and see what happens? How steep is the hill? Reason being is that I managed to get mine to smoke by parking it sideways on a steep hill [with no thrashing] Q3- Oil guage should be accurate and the levels you suggest don't sound overly heavy to me. If you've not noticed any difference since getting the separator "fixed" to beforehand than it still could be residual Glad to hear it's back in with JZM though and also VERY keen to hear what the outcome is, as I'm sure it will be directly relevant to me also