bonus_2000 Posted May 22, 2007 Share Posted May 22, 2007 Hey peeps, Sorry for this, bit of a long one. . . . Wondering if some of you technical people can possibly steer me in the right direction with regards to problems with my engine. Recently undertaken the coversion from TT to single T67 from Boostlogic. Thought as the engine had covered 90k miles, that it was sensible to have it out and rebuild before all this went on. The engine came apart, had the block sent away for hone, the bottom end lighten and balanced. That came back no worries. Sent the head away to be checked and have the head work done that I wanted. He also recut the valves for me. While this was going on, I collected all the other nessessary parts to complete the rebuild, new oil pump, water pump, gaskets, seals, ings, bearings, ARP bolts etc. Once I had everything back a few friends (who are in the trade) and I put the engine back together. Everything seemed to go fine, and when it was completely back together turned it over and all seemed good. We went from here and put the engine back into the car. Initially had some issues with it running, which turned out to be a dead coil pack. Once diagnosed and replaced all seemed good. I have Emanage management fitted while the engine was out, because of the change to large injectors (720cc), which in the first instance was over fueling. This was adjusted back (I have an Innovate AFR), but couldn't get it perfect, and run for a number of miles like this. In the end I contacted IanC (top bloke!) when I was really concerned about the oil consumption, who managed to write and send me a map that was just about perfect for my car Only problem is it is still burning oil. I expected it to burn some oil when running this in, but in the 700 miles I have covered so far I am seeing too much of this stuff burned! The car mainly smokes on overrun, but that is what i can see, nothing to say it isn't the rest of the time? I doubt this is valve stem seals, i replaced all of these with new? Is this still a possiblility? I very much doubt it is turbo - Brand new T67? should i rule this out? The oil feed and return are fine, checked these. Boost pipes are bone dry. Removed exhaust from V band and all looks good, just sooted up. Piston oil sealing rings? - Very possible? Can these be put on up side down? May sound a silly question now I know I am using stock pistons and rings. Got a feeling that it is either something silly like this or it has been borewashed I have performed a compression test and cylinder leak down test on the car, which all seem to come back with encouraging results - 138psi there abouts on all cylinders, and between 5 and 9 % leak on each. I know this doesn't mean the oil sealing rings are good? There appears to be some oil on some pistons too, not loads. The plugs that came out, 3 or 4 plugs seemed to be a sandy colour, and a couple were black (not sure if this is oil or fuel?). I have ordered a new PCV today, wondered if it would be worth trying for 15 quid to see? I have pretty much convinced myself that this is going to be engine out again, which isn't a problem, but don't want to go to those lengths if it isn't going to sort this out? What are everybody's thoughts on this, sorry I know it's alot to take in all at once! But any help would be appreciated here Thanks All Link to comment Share on other sites More sharing options...
b_have Posted May 22, 2007 Share Posted May 22, 2007 What piston/cylinder clearance did you measure after the hone? Did you check installed ring gap? Link to comment Share on other sites More sharing options...
bonus_2000 Posted May 22, 2007 Author Share Posted May 22, 2007 The guy that honed the block and did the lighten and balance measured everything for me - i.e. the crank for the big end shells and main shells, and the bore and pistons for the ring sizes. We just assembled it. Sorry that isn't prob much help. I can remember he polished the crank so they were all the same size, Size 2 Bigends and Size 3 Mains. He also told me which rings to buy, from the toyota chart. Link to comment Share on other sites More sharing options...
bonus_2000 Posted May 28, 2007 Author Share Posted May 28, 2007 Changed all of the valve stem seals yesterday, and that doesn't seem to have had any effect Suppose that has at least ruled them out. Any other ideas guys? Link to comment Share on other sites More sharing options...
Digsy Posted May 28, 2007 Share Posted May 28, 2007 If it was your breather system (PCV) I'd expect all the spark plugs to look as bad as each other. Reading your initial post I was thinking piston rings because of your re-hone, but you already said that you had these measured properly. Valve stem oil seals would be an smoke on startup thing. What oil are you running it in on? Link to comment Share on other sites More sharing options...
bonus_2000 Posted May 28, 2007 Author Share Posted May 28, 2007 I'm still running in, so it's running on mineral oil 20-50. Changed the PCV too yesterday, just on the off chance. . . Link to comment Share on other sites More sharing options...
Digsy Posted May 28, 2007 Share Posted May 28, 2007 Cool. Any change since you swapped out the PCV valve? I wouldn't have thought so, but correct valve operation would be important on the overrrun. Link to comment Share on other sites More sharing options...
bonus_2000 Posted May 28, 2007 Author Share Posted May 28, 2007 Yeah see your point. I checked the old valve when I took it out, and it appeared to be ok, but changed it anyway. Not sure if this helps, but it does smoke when you come off the throttle, and allow it to over run, no smoke, then when you touch the throttle - smoke! It must burn the oil it has pulled in? Link to comment Share on other sites More sharing options...
Digsy Posted May 28, 2007 Share Posted May 28, 2007 #Not sure if this helps, but it does smoke when you come off the throttle, and allow it to over run, no smoke, then when you touch the throttle - smoke! It must burn the oil it has pulled in? Don't think I understand that completely. Can you elaborate? Link to comment Share on other sites More sharing options...
bonus_2000 Posted May 28, 2007 Author Share Posted May 28, 2007 Sorry, l just read that back again wasn't too clear! If I was to drive the car and come to a hill for instance, I would engine break down the hill. When I come back on the throttle after it will puff the smoke out of the back. Link to comment Share on other sites More sharing options...
Digsy Posted May 28, 2007 Share Posted May 28, 2007 Just a puff, or continuously while you have the accelerator down? Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted May 28, 2007 Share Posted May 28, 2007 If it was over fuelling badly, it could be ring related, the compression test is OK for a newly rebuilt motor, but i would expect a bit more after 700 mls, if it had forged pistons and correct rings i wouldn't be that surprised that it was burning a little oil, but what you describe does sound excessive, smoke after closed throttle is usually guide/seals or turbo seals, but could still be rings as there is a lot of vacuum on closed throttle. Link to comment Share on other sites More sharing options...
bonus_2000 Posted May 28, 2007 Author Share Posted May 28, 2007 No it isn't continuous when you put the accelerator back down, just a fair size puff of smoke. It varies really with the ammount of over run. Link to comment Share on other sites More sharing options...
b_have Posted May 28, 2007 Share Posted May 28, 2007 Do a leakdown test. Sounds to me like piston/ring issue. Link to comment Share on other sites More sharing options...
bonus_2000 Posted May 28, 2007 Author Share Posted May 28, 2007 This is the strange thing, we have done both compression test and leak down tests, and both have come back with positive results. When we did the valve stem seals at the weekend, we used a leak down tool again when keeping the valves in place, and the reading that were coming off were fine. Around a 5 psi leak per cylinder. Link to comment Share on other sites More sharing options...
Digsy Posted May 29, 2007 Share Posted May 29, 2007 No it isn't continuous when you put the accelerator back down, just a fair size puff of smoke. It varies really with the ammount of over run. The more overrun, the bigger the puff? Link to comment Share on other sites More sharing options...
77miles Posted May 29, 2007 Share Posted May 29, 2007 I have the same problem! I too have had my engine re-built the same as yours bores honed, new rings, oil pump, water pump,valve stem seals ect, ect. I have done about 1500 miles now and still get the cloud of smoke on over run but it is not as bad as it was at first. The only thing I have done different is I have removed the first cat which could be causing the turbo oil seals to leak but then again these were low milage turbo's I bought of Ian c last year so I don't see how it can be them. Link to comment Share on other sites More sharing options...
Chris Wilson Posted May 29, 2007 Share Posted May 29, 2007 Sounds like running it crazy rich on new rings and bores has *uggered it. You will, at the VERY least, need a full engine strip, a hone and new rings. Worst case is another rebore (you DID NOT go to 87 mm straight away, did you.... ?) and new pistons and rings. You need the pistons checking by someone competent with a good outside micro,eter, and the bores with a simialr person used to using a Mercer gauge. Link to comment Share on other sites More sharing options...
bonus_2000 Posted May 29, 2007 Author Share Posted May 29, 2007 Hi Chris, Luckly I am still using standard size pistons and rings, so should be ok from that side of things. You definitely think it will be rings? Link to comment Share on other sites More sharing options...
bonus_2000 Posted May 29, 2007 Author Share Posted May 29, 2007 The more overrun, the bigger the puff? Basically yes, the longer I stay on overrun, the larger the puff of smoke. Link to comment Share on other sites More sharing options...
Chris Wilson Posted May 29, 2007 Share Posted May 29, 2007 Yes, my money would be on bore wash. You ^MUST^ get an engine mapped as soon as it is started and you ^MUST^ start mapping from idle. It's madness to build some wild engine (wild meaning bigger injectors, N/A to turbo, different fuel pressure, blah blah) and then drive it to a mappers or furtle around in it for hours beforehand. You should be *AT* the mappers for when it *FIRST* fires up!! Link to comment Share on other sites More sharing options...
bonus_2000 Posted May 29, 2007 Author Share Posted May 29, 2007 Would my best bet be to get it mapped as it is now, and then do the rebuild work, then knowing the fueling is good? Link to comment Share on other sites More sharing options...
Chris Wilson Posted May 29, 2007 Share Posted May 29, 2007 Would my best bet be to get it mapped as it is now, and then do the rebuild work, then knowing the fueling is good? Not a bad idea at all, get a base map now, but check it again after the remedial work. Link to comment Share on other sites More sharing options...
bonus_2000 Posted May 29, 2007 Author Share Posted May 29, 2007 I have had Ian C do me a base map, probably too late tbh. Would it be worth me getting him to fully map it now? Then rebuild? Or just stick with what I have now and rebuild? Link to comment Share on other sites More sharing options...
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