i have same problem new exaust now white/grey smoke and I have no balance pipe also. will install over weekend and see if fixes fault
Hey mate just wandering how much K?s you Engine done. If the turbo are been rebuild and it?s been check I suggest there are two things you can get smoke from. Engine stem seals valves are worn out. Need to replace it. Piston rings do a compression test cold and hot and see the difference. Hope this helps Bad valve seals Worn valve guides Pressurized crankcase (oil pan) due to a clogged PCV valve or breather system Blow-by from worn piston rings Bad valve seals: The valves are located in the cylinder head above the combustion chamber. Oil is pumped at 50 to 80 psi of pressure into the top of the head, lubricating the valve-train; the valves have seals on them to stop the flow of oil down into the engine when the valve is open. If the seals fail, oil is allowed to flow down into the combustion chamber and is burned. Worn valve guides: The valves are guided by a small cylindrical chamber called a valve guide. These guides wear over time causing eccentricity (or slop); the excess gap allows the flow of oil down the valve stem into the combustion chamber to be burned. What about the valve seal you say? Well, the gap is too great for the seal to stop the oil flow, so down it goes to be burned. Pressurized crankcase due to clogged PCV or breather system:The car's engine is a giant pump, consequently it must breathe. The PCV (Positive Crankcase Ventilation) system does just this, allows the engine to exhaust the excess pressure build-up (which is a natural phenomenon of the internal combustion engine). Carbon build-up is a by-product of an engine and can build up in the PCV system, clogging the breathing passages. This in turn pressurizes the oil pan and pushes oil up into the fuel delivery system, where it is fed into the engine and burned. Blow-by from worn piston rings: The pistons in your car's engine have seals around them in the form of rings. These rings do two things: Seal the combustion chamber so the precious power developed from the firing of the cylinder is not lost. Provide vital lubrication to the cylinder walls. When the rings wear out, the pressure from combustion reverses down into the oil pan, pressurizing it and forcing oil into the valve covers, through the breather system, back into the fuel delivery system, and into the engine to be burned. Please correct me if I m wrong.
Which seal? Was wondering which seals your refering to. Turbos or valves.For as far as my knowledge and experience goes I have never heard of lack of back pressure doing either.
Smoke issues Causes of smoke are many and varied. As Baron said the PCVs get blamed for a lot but they are easier to check than valve stems and seats. To test the seats, requires a leak down test. There is no real definative way to check the valve stems, or their seals. You could try a intake manifold pressure test and listen through the oil cap. For the others with similar, the reason why the smoke goes away on boost or off idle is that the negative pressure in the manifold reduces and the oil is no longer drawn down pass the valve seal. For the other in this similar situation that have the smoke go away after warming the car up. It is either the pistons or valves warming up taking up the tolerence. Now when I refer to the "Smoke" i mean that blue oil smoke not other forms. As for the change of exhaust causing the smoke, I think it may have to do withwhat occured while fitting the pipe. And, the fitting of a cross over pipe. Hmmmmm, sounds a bit strange as I have never heard, experienced, or any knowledge of this addressing this problem before. Acutally cross over pipes only make sense in NA or supercharged cars, where the pulses are stilll running through the pipes. A turbo essentially "chops" these up.
The reason/theory OK so here goes Please don't doubt this theory in public as unless you have seen it work you may be costing members thousands by sending them off changing seals and turbos etc when there may be no real need. I purchased a TT Z32 over six years ago, the engine and turbos were very tired and smoked a little - not a lot a little. The exh was screwed and falling apart so I replaced it, 2.5 inch the whole way through with two resonators and stainless mufflers (one of each per bank). Now I had a serious smoke issue - exactly the same symptoms as above posts. I replaced the engine with a know good engine and had the turbos overhauled so the entire eng system was replaced/repaired. IT STILL SMOKED! At this point I doubted the turbos had been done correctly as this is typical worn turbo smoke signals, I approached the turbo shop and they did some research as did I. When we got in contact with each other again we found we had both got the same advice from several other people - BALANCE PIPE ON THE EXH? We had a think and decided to try it as it is cheap and the previous system had one and it smoked heaps less (remember I changed the engine & OHd the turbos after then). I took the car to a local Pitstop who laughed at me and said it will never work. The guys were so convinced I was wrong they made me point out the exact place to put the pipe and show how long it had to be and what diameter (they really were having a go at me). Well I had the last laugh we started the car after the pipe had been fitted and left the car sitting for a good 15mins with no smoke at all. Straight off the bat the problem was sorted Pitstop ended up only charging half the price they were so embarrassed. This fix worked for over two years until ultimately the turbos wore from abuse and began smoking again - they have now been replaced with BB type........ THE THEORY: OK so we have a V6 firing order 123456 so we have a pulse of exh on one side then a gap then another then a gap etc etc etc while the other side does the same in the gaps from the first side. Engine idling at around 700RPM being a four stroke thats 350 exh beats per minute per cylinder, six cylinders thats 2100 per minute, half each side so around a thousand exh pulses per minute past/through the turbo (1000Hz) Imagine you have a crapy little partly worn turbo seal being bounced backwards and forwards on its shaft at 1000Hz with relatively high oil pressure on one side and low exh pressure on the other - isn't there just the slightest chance this could create a pumping situation where even the smallest amount of oil could be drawn through into the exh? We are talking around two or three drops of oil a minute here not liters of the stuff. Go and change all the valve guide seals if you want and the piston rings and overhaul the turbos etc etc etc or if you like put the balance pipe back in as per the original design (the resonators at the back are joined) and hope that ya haven't already done to much damage. We have had the turbo Zeds over here in NZ for at least ten years in large numbers and many many people have been caught out by this same mistake. Some of the cars above may have worn turbos etc and may smoke even with the pipe fitted but I betting there will be others this will fix. Oh and by the way I'm an ex aircraft engineer who has now gone to the automotive industry so there are a few brain cells behind the posts. Happy arguing for those that doubt and best of luck to the smart ones who will try it.
Mungyz, you may have a point I can see the theory behind this, it has merit. And it would be able to be proved too if it is you turbo/s seal/s weres uffering with this, by disconnecting a cylnder coil and getting the pulses right out of order. A balance pipe as close to the turbos as possible would address this pulsing, if it is making it pass the turbos. I'm curious did your smoke issue occur, b4 the x pipe, while at idle and under load? And, did the x-pipe do anthing else?
At idle once the car was warm and only after idle for more than two minutes or so. As I said I changed the exh and then this started prior to that it was just typical worn motor type smoke - a general blue haze most of the time LOL! The balance pipe cured/at least postponed the smoking issue and unfortunately took the nice harsh sound out of the exh and reduced it to a softer sound though still of similar volume. I'm not sure pulling a coil lead would show the same results as there would still be a pulse from each cylinder (though the dead one would be far less). As we all learned in science at school if something changes we need to look at what we did to make that change. Car goes fine, fit big exh without balance pipe, car smokes. What have we changed - exh size and removed balance pipe - hmmm makes ya think aye. With my Zed the only real change made was the removal of the balance pipe as the exh system was replaced with one of the exact same size etc so theres a bigger clue for ya Fairly strange problem this, I tried blocking one pipe with a rag to create back pressure on that bank but that didn't work LOL! Oh well back to my TT to NA conversion and NA to TT conversion - I have parts spread over my whole driveway LOL!!
Thanks Mungyz. Thats sound crazy enough that it might just work. I had found in testing that when the exhaust was smoking if I removed the exhaust from the dump it stopped smoking. If i just push the exhaust back up to the dump by hand withing 30 seconds it would start smoking again. This is backwards to the turbo leaking due to lack of back pressure theory. I had thought that oil may be pumping/siphoning due to pulses in much the same way that a tuned pipe on a 2stroke engine sucks the exhaust out. Not having a strong technical background it was hard to itterate. Engine problems would have been problems before the bigger exhaust was fitted. Regardless its a cheaper option to try than rebuilding an engine to maybe solve a problem. I will have a pipe fitted this week and Ill let you all know how it goes. Good luck to me
Another Idea for thought. Are those that are having the same problems using split dumps? Tuneagent Style.
Mines smokes up HEAPS sometimes, but it seems to be only on first startup and ONLY when i put it in park with handbrake on.. I just brushed it off as condensation as theres usually lots of water spitting out of the exhaust after it happens anyway.
Had a balance pipe fitted today. 2" halfway between the cats and the diff. I am delighted to say that the smoke issue seems to have disappeared. Mia was stuck in traffic after she picked it up and it didn't puff a wisp of smoke. Been stuck in traffic has been an embarrassing situation recently I let it idle for 10min after i took it for a blat this arvo and it was good as well. I cant stop smiling tonight.:biggrin: Mungyz thanks for your input, I dont know how much more dosh I would have thrown at the problem without a result. :bow2: For others having the problem, it only cost $85 to have the pipe fitted. So get onto it and see if it works for you. Happy Ztoy again:zlove:
Congrats on the fix ,nice and cheap to. Well i learnt something today who would of thought a balance pipe would do the trick. Regards, Trev
Vote to tech section! Maybe it is caused by some sort of ressonant frequency? And now you have a spare turbo just in case
if this is the actual cure then this info and solution should be widespread to everyone. I've heard similar issues time and time again. My mini had exactly the same problem the other week and i've now bought a new engine to go in it next week! (however, a slightly different kettle of fishskies Woot!)
to put it technically, that is some weird shit. I'm glad its fixed Al, that was an ongoing problem for yonks!
LOL omg i bet you wish you knew that before you started taking turbos apart. Have you got a pic of the exhaust? Just to be sure you put the exhaust just before the diff, in the original position.
