dukenukem Posted September 18, 2009 Share Posted September 18, 2009 (edited) My RZ seems to have had a boost leak for some time. I get 0.55bar off the 1st turbo and 0.65 off the 2nd. I bypassed the VSV's and put the car in TTC mode and still get the same 0.65 bar max so can't be the VSV's, thought probably a leaky hose. Tonight, me and 'dangerous' blanked off the 3" pipe going into the throttle body and put a valve into the pipe section going from the turbos to the SMIC and pumped it to 1.5bar. Couldn't really find any obvious leaks but probably need to take the front bumper off and the offside arch to really inspect the SMIC for a leak. It doesn't seem in good condition though and the concertina pretty much disintegrates at the touch. I'll inspect that for leaks another time when I can take the whole front off the car. Big problem tonight seems to be the small puffs of white smoke when blipping the throttle. When we undid the clips on the pipe from the turbo to the SMIC we noticed a film of black oil inside the pipe. At the inlet to the throttle body it was much cleaner (but maybe a very small amount). This white smoke and oil in the air feed seems like a turbo seal to me. Can anyone confirm this? The oil level is 3/4 between min and max and has hardly changed since the last oil change about 2000 miles ago. I note white smoke could be valve stems or head gasket. Rather worried about all this as I am properly SKINT! Any help with any of the above would be much appreciated. Edited September 18, 2009 by dukenukem (see edit history) Quote Link to comment Share on other sites More sharing options...
dukenukem Posted September 18, 2009 Author Share Posted September 18, 2009 (edited) Ok, another question, if the white smoke was caused by the head gasket the oil would be cloudy right? If the white smoke was the stems, does the oil pressure change? What if the smoke was coming from the turbo seal? How do you know??! Edited September 18, 2009 by dukenukem (see edit history) Quote Link to comment Share on other sites More sharing options...
tooquicktostop Posted September 18, 2009 Share Posted September 18, 2009 Valve stem seals is usually only smoke on start up, especially when left for a while, it clears after a few seconds, white smoke when running could highlighting another issue A "sniff test" at a reputable garage will determine head gasket but it is rare in the Supra, it sounds more like oil through turbo seals to me Quote Link to comment Share on other sites More sharing options...
dukenukem Posted September 18, 2009 Author Share Posted September 18, 2009 (edited) Valve stem seals is usually only smoke on start up, especially when left for a while, it clears after a few seconds, white smoke when running could highlighting another issue A "sniff test" at a reputable garage will determine head gasket but it is rare in the Supra, it sounds more like oil through turbo seals to me I had the car at a local Jap performance specialist. They couldn't find any boost leaks. The car is 13 years old and the pipe work is all stock. I'm not surprised it's black on the inside, but then again low boost, oil in the air pipes, white smoke, all seems to point to bye bye tubbies. I always imagined when turbos go out, they go out in an amazing blaze of glory, with bits of ceramic blades and fire all over the place. The car sounds and feels perfect. Edited September 21, 2009 by dukenukem (see edit history) Quote Link to comment Share on other sites More sharing options...
legendswraith Posted September 21, 2009 Share Posted September 21, 2009 Due to the way you described the car at JAE and we eliminated it leaking at the BOV i think it may be mechanically based rather than solenoid especially still getting the same boost in true twin http://www.mkivsupra.net/vbb/showthread.php?t=35926&highlight=boost+level+turbo is a good thread for troubleshooting As i haven't had your type of problem myself a guess would be either the wastegate is not doing its job properly or an issue with the EGCV. Theres more than a few who have had more tubby trouble than i who should be able to shed more light, but if you can absolutely definately discount the vsv's it might be worth exposing the turbos and seeing if there is anything glaring there Quote Link to comment Share on other sites More sharing options...
dukenukem Posted September 21, 2009 Author Share Posted September 21, 2009 Due to the way you described the car at JAE and we eliminated it leaking at the BOV i think it may be mechanically based rather than solenoid especially still getting the same boost in true twin http://www.mkivsupra.net/vbb/showthread.php?t=35926&highlight=boost+level+turbo is a good thread for troubleshooting As i haven't had your type of problem myself a guess would be either the wastegate is not doing its job properly or an issue with the EGCV. Theres more than a few who have had more tubby trouble than i who should be able to shed more light, but if you can absolutely definately discount the vsv's it might be worth exposing the turbos and seeing if there is anything glaring there Hi Mate, I think you might be on to something r.e. the wastegate, although I would like to pressure test the system again to check the hoses but use a mechanical boost gauge / pressure gauge to measure the pressure in the system vs pressure from the compressor. My electric gauge just read zero (but might not be sampling from the region we tested), we pumped up to 2 bar in from the compressor and tried to listen for leaks. I started the car today, puff of white smoke straight away and then it was more or less clear, so I think it's the valve seals which wouldn't be so expensive. Black oil film in the pipe from the tubbies to the SMIC though? Is this to be expected in a 13 year old car with 60,000 on the clock or should I be worried? Quote Link to comment Share on other sites More sharing options...
legendswraith Posted September 21, 2009 Share Posted September 21, 2009 the oil film is more than likely the oil that is blown into the journals leaking past the seal as long as its just a film its not the end of the world, if its wet or dripping its trouble. Valve stem seals won't lose you the boost either so i would think your smoke may be related to the low boost too. It'll probably be something screamingly obvious when you find it Quote Link to comment Share on other sites More sharing options...
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