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Discussion Starter #1
coming back from jap show last sunday i noticed white smoke coming out the back when changing from fourth to fifth and again from fifth to sixth. it only happens in these two gears and when driving in a "spirited" nature. I have checked all fluid levels and these seem to be normal. the problem is the same whether the engine is cold or hot. the exhaust has also been popping but have been told this is normal, just unburnt fuel/gases, burning in the exhaust. if anyone could shed any light i would be grateful otherwise its off to garth next weekend.
 

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is'nt white smoke useually to do with water geting in (headgasket) i hope not for your sake and i dont want to scare you

but i'm sure someone will come along shortly who knows a bit more about this type of thing
 

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formerly known as mruk
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had HG problem on my last car and that was pissing white smoke... someone told me white smoke might be a turbo problem though - don't know how much he knows about cars though
 

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Discussion Starter #7
cheers guys for the help. if it was head gasket wouldn't it happen all the time. you can redline in first to fourth without any problems and then fifth and sixth white smoke. the engine has only been in the car six months and presumed all new gaskets were fitted. dont really know so hopefully getting it sorted next week.
 

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Discussion Starter #9
didn't mean it like that. what i meant was however the car is driven the problem doesnt occur in first four gears. Anyway redlining in all gears would no doubt end up breaking all speed limits and that is illegal, but good fun!!
 

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I'm not sure if any of this will help, but it might point the finger at a couple of area for you to check :)

White smoke from the exhaust system is often quite benign: It will most frequently be steam from condensated water that evaporates in the hot exhaust system.

This will often happen when the engine is still cold - once your engine gets warm and the humidity has evaporated from the exhaust system, the white smoke disappears. Generally: nothing to worry about.

If your car has an even flow of white smoke, even when it is running nice and warm (after, say, 30 miles), make sure you check your coolant fluid: If it is depleting, you may have a leak in the head gasket, a problem with the cylinder head, or even just a cracked seal somewhere. Make sure to keep your cooling fluid topped up, and get to a garage when you have a chance - it may be nothing, but it could be serious.

If huge billows of large amounts of smoke are coming from the car, but not necessarily from the exhaust system, it may be a problem with the brake fluid. The hydraulic oil that keeps the pressure in your brake system smokes a lot when it comes into contact with somehting hot (such as your exhaust system or the hot brake discs). It may be a leaking brake cylinder or crack somewhere in the brake system. Obviously, this can be quite dangerous, and it is worth getting it checked out sooner, rather than later.

1. The engine is producing the smoke

Valve stem seals on older engines can allow excess oil to enter the combustion chambers. This will manifest itself as exhaust smoke (smelling of burnt oil) during idle and deceleration mainly, but in reality the smoking will be constant. These symptoms are quite similar to those of a turbo bearing being out of spec. Changing these seals means taking the cylinder head off and dismantling the valves - not a bad thing to do on a high-mileage engine, anyway.

The piston rings could also be tired and loose, letting excessive 'blowby' go through the rings, pressurising the sump and getting out via the crankcase ventilation (thick pipe next to oil dipstick -> camcover sealed passages -> thick pipe at back of camcover -> turbo intake). This can be 'rectified' (read:: botched) by blocking off the small intake pipe at the turbo end, and venting the camcover pipe to the atmosphere via a small airfilter, and/or an oil catch tank. These blowby gases are poisonous and corrosive, so we don't want to breathe them if we can avoid it!

2. The engine is forcing the turbo to produce smoke

Blocked breather pipes would fall into this category. They could be full of oily and sticky residues becoming effectively blocked, or kinked. This would lead to the sump becoming pressurised, creating pressure that would not allow the turbo oil return to flow (it's gravity-run, remember, as opposed to the turbo oil-feed that's pressurised). Therefore fresh oil would be piling up through the oil feed, but with no easy exit, the oil will have to push itself back through the turbo seals finding itself both into the intake charge and directly to the exhaust gases. Fixing this blockage would correct the problem immediately.

For idle and very low throttle openings, the LET also has a smaller breather hose from the camcover to the bottom of the inlet manifold - via a flimsy one-way valve. This valve ensures that under boost the camcover isn't pressurised. It only helps suck out the crank fumes while off-boost.

3. The turbo is smoking

That's when the clearances within the turbo are out of spec and oil leaks through the seals whenever there is pressure differential. High-flow exhausts exacerbate this problem, as of course running high boost pressures.

There is this theory that 'thin' oil leaks through the seals while 'thick' oil doesn't. Conventional wisdom would support this argument, but I have seen no evidence whatsoever to back it up, despite changing from the thinnest of oils (synthetic 0w40) to the thicker ones (15w50).
 

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formerly known as mruk
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sorry i know its off topic steve, but is yours the white R34GTR i've flashed a few times in luff? I'd just got it back from being resprayed that day, pulled out of my road and its big daddy was there :D
 

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hey it's more than likely your head gasket. i really hope it isnt! as 'EvilR32' said

white smoke = HG (normally)
Blue smoke = Oil

Im also thinking maybe this could be your thermostat? Just a thought mate

best of luck

:smoker:
 

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Discussion Starter #13
cheers for the help everyone. if the headgasket has gone dont you normally get 'mayonaise' on the oil filler cap, or is that just after a long period of time and the coolant level would drop surely.
yes that was me you ignorant bar steward.
 
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