Cable Posted July 17, 2007 Share Posted July 17, 2007 I've just fitted my decats and now I'm experiencing a little white smoke. It doesn't smoke during normal driving, on boost or even coming off boost. It only occurs when I've come to a stop and idling like when you come to a set of traffic lights. It wafts out for a second and then just stops. Any ideas Quote Link to comment Share on other sites More sharing options...
suprafan72 Posted July 17, 2007 Share Posted July 17, 2007 condensation? increased gasses? Quote Link to comment Share on other sites More sharing options...
Cable Posted July 17, 2007 Author Share Posted July 17, 2007 condensation? afraid not, definately smoke, but not a massive amount. Just a puff when I come to standstill. Quote Link to comment Share on other sites More sharing options...
johnnyknox Posted July 18, 2007 Share Posted July 18, 2007 free bump Quote Link to comment Share on other sites More sharing options...
Cable Posted July 19, 2007 Author Share Posted July 19, 2007 anybody? Quote Link to comment Share on other sites More sharing options...
Soop Dogg Posted July 19, 2007 Share Posted July 19, 2007 Valve stem oil seals. I've had this happen to 3 Supras as soon as I've decatted them. Happens as you state after a short time on idle or sometimes on starting the engine. Normal driving shows no problem. Seals are about £120 for the full set, but if you have to have someone else do the work it'll probably cost a fair amount to do them. They can be done with the head on (TLicence on here did a guide on how to change them a while back) but a lot of garages will quote you for taking the head off - which will be BIG bucks! I've done them myself with the head on and it's actually not a bad job to do - very time consuming, but not that bad really. Edit: Here is the guide by TLicence: http://www.mkivsupra.net/vbb/showthread.php?t=49859&highlight=rope Quote Link to comment Share on other sites More sharing options...
Cable Posted July 20, 2007 Author Share Posted July 20, 2007 Thanks for that Soop, not quite the news I wanted but that's how things go I suppose. I'm curious as to why this occurs to the valve stem seals when decatting, anybody know why? Thanks Neil Valve stem oil seals. I've had this happen to 3 Supras as soon as I've decatted them. Happens as you state after a short time on idle or sometimes on starting the engine. Normal driving shows no problem. Seals are about £120 for the full set, but if you have to have someone else do the work it'll probably cost a fair amount to do them. They can be done with the head on (TLicence on here did a guide on how to change them a while back) but a lot of garages will quote you for taking the head off - which will be BIG bucks! I've done them myself with the head on and it's actually not a bad job to do - very time consuming, but not that bad really. Edit: Here is the guide by TLicence: http://www.mkivsupra.net/vbb/showthread.php?t=49859&highlight=rope Quote Link to comment Share on other sites More sharing options...
Fifty Posted July 20, 2007 Share Posted July 20, 2007 I thought it was turbo seals accentuated by decatting? valve stem seals are common and happen with age. maybe Im wrong but.... Rich Quote Link to comment Share on other sites More sharing options...
Ian C Posted July 20, 2007 Share Posted July 20, 2007 Less back pressure in the exhaust system due to decatting means some oil can now be drawn through worn exhaust-side stem seals I guess. -Ian Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted July 20, 2007 Share Posted July 20, 2007 Turbo seals are tired, less back pressure in the exhaust means the waddle on the seals pumps a bit of oil into the trubine housings. If it was stem seals it would have done it prior to the de catting. Very common, live with it or buy new turbos. Oil is cheaper... Quote Link to comment Share on other sites More sharing options...
Cable Posted July 20, 2007 Author Share Posted July 20, 2007 If it was stem seals it would have done it prior to the de catting. QUOTE] Could this be the time to go single? I still find it odd that it only does it on idle for a few seconds. I would of thought that it might kick out a big puff of smoke when coming off boost or something Quote Link to comment Share on other sites More sharing options...
SMiFFAD Posted July 20, 2007 Share Posted July 20, 2007 Sounds very similar to mnie, pretty much every time i stop, idle for a second and drive off again i get a puff of smoke. Im fairly sure its stem seals as the car had hybrids put on it about 20K ago, surly they cant have conked out by now! Quote Link to comment Share on other sites More sharing options...
Soop Dogg Posted July 24, 2007 Share Posted July 24, 2007 Turbo seals are tired, less back pressure in the exhaust means the waddle on the seals pumps a bit of oil into the trubine housings. If it was stem seals it would have done it prior to the de catting. Very common, live with it or buy new turbos. Oil is cheaper... I really don't like to disagree with you Chris as you are waaayyy more knowledgeable than I, but I've had this on a number of Supras and they ALL started smoking only when they were decatted. In fact the second one I decatted started smoking on the trip home from having the exhaust made up when I stopped in a petrol station - made me feel sick at the time! Also, they seemed as clear as a bell with the cats in place. (Not sure if the cats held back some of the particles in the exhaust gas or what, but that's how it went on my cars anyway.) Also, once the valve stem seals were replaced, it cured it straight away - my current car is testament to this and it's now back on the original stock turbos - no smoke whatsoever. (Turbos have nearly 100k miles on them) If the turbo seals were suspect, wouldn't you see smoke under power? (Genuine question, by the way - I'm not porporting to know the answer to that one.) Quote Link to comment Share on other sites More sharing options...
Rayman Posted July 24, 2007 Share Posted July 24, 2007 I've just fitted my decats and now I'm experiencing some white smoke. It doesn't smoke during normal driving, on boost or even coming off boost. It only occurs when I've come to a stop and idling like when you come to a set of traffic lights. It wafts out for a few seconds and then just stops. Any ideas You got some nice cars in your garage! You still got them all? Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted July 24, 2007 Share Posted July 24, 2007 Smoke source is always a bit of a gamble, in my experience a car that smokes only after it's de catted is most likely to suffer from tired turbo seals. It may be stem seals, but I have never found this the case unless the car smoked BEFORE cat removal, too. Interesting, maybe one of the other people who have posted about smoking after a de cat will get the stem seals done, and leave the turbos, and see what happens? Quote Link to comment Share on other sites More sharing options...
rob wild Posted July 24, 2007 Share Posted July 24, 2007 Dont really want to disagree either but if it was turbo seals or valve steam seals the smoke would be blue? Or it was on mine. White smoke is normally coolant? Have you checked your coolant level? Also maybe take either a picture of the smoke or a short video? Cheers Rob Quote Link to comment Share on other sites More sharing options...
ads274 Posted July 24, 2007 Share Posted July 24, 2007 I think rob is correct. I've had two mates with supras change their stem seals. The trademark sign seems to be blue smoke on startup, does the original poster have that? Quote Link to comment Share on other sites More sharing options...
BASHTHEBISHOP Posted July 24, 2007 Share Posted July 24, 2007 The trademark sign seems to be blue smoke on startup, does the original poster have that? I agree with this...this is what mine does. Have spoken to a few people now who say its valve stem seals when blue smoke omitted on startup. Is there any risk of causing damage by not having these replaced? Strangely it doesnt seem to be eating any oil:search: Quote Link to comment Share on other sites More sharing options...
Cable Posted July 29, 2007 Author Share Posted July 29, 2007 Thanks for all the responses guys, I've been on holiday so not had a chance to reply. The trademark sign seems to be blue smoke on startup, does the original poster have that? Nope no blue smoke at any time. To add to the strangeness I've been out for a drive in it today and the smoke problem seems to have disappeared. Another thing I was thinking of was could it have been the sealant the exhaust fitter used as I think he may of caked it with a silicon liek sealant and after a while it burnt any excess away? Quote Link to comment Share on other sites More sharing options...
Cable Posted July 29, 2007 Author Share Posted July 29, 2007 You got some nice cars in your garage! You still got them all? thanks, unfortunately not Got my sup and humble MX5. Though the blue civic is up for sale again, tempted... Quote Link to comment Share on other sites More sharing options...
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