Jake Posted February 12, 2007 Author Share Posted February 12, 2007 I'd send the turbo to a good rebuiders for a check over for a start. Actually that was my plan until Jarrett said it's almost certainly not a turbo problem. I've been waiting 8 days for a tech person from Turbo Dynamics to ring me back. Their girl who answers the phone doesn't seem able to give me any info and always promises somebody will call me, but they don't. If it didn't have a rebore with oversize pistons I'd budget for just that, I'm afraid. How long did it run un mapped after the rebuild, in all honesty???? Depends what you call un-mapped. It was already mapped before the rebuild and again afterwards. Sadly I don't have much info or details about what happened with the rebuild. You can knacker rings in an hour with a very rich setting. Are you 100% sure it now runs a sensible fuel map? Well the AFRs seem good now. I'm no expert but I think it's mapped fine Has it got datalogging enabled? If not get it unlocked and run a wideband and post me some traces. Thanks. I'll see if I can borrow a CAN cable from someone. Quote Link to comment Share on other sites More sharing options...
uk-rich Posted February 12, 2007 Share Posted February 12, 2007 why not pull the turbo and have it looked at, easy job and would rule it out Quote Link to comment Share on other sites More sharing options...
Gamer Posted February 12, 2007 Share Posted February 12, 2007 I have a CAN cable if you need to borrow one Jake, keep in mind though if data logging is not enabled on your ECU, it costs a bit to get that feature enabled. Quote Link to comment Share on other sites More sharing options...
Kranz Posted February 12, 2007 Share Posted February 12, 2007 I'll do you an oil analysis mate and let you know what the culprit/faulty component it is Quote Link to comment Share on other sites More sharing options...
Jake Posted February 12, 2007 Author Share Posted February 12, 2007 I have a CAN cable if you need to borrow one Jake, keep in mind though if data logging is not enabled on your ECU, it costs a bit to get that feature enabled. That's very kind of you Joe. I'll see if Dan knows whether my Motec's logging is enabled (I suspect not) or how much to turn it on. I'll do you an oil analysis mate and let you know what the culprit/faulty component it is Thanks I've just ordered a kit Quote Link to comment Share on other sites More sharing options...
dangerous brain Posted February 12, 2007 Share Posted February 12, 2007 Can you tell the difference between piston ring debris and turbo charger bearing debris in the oil? I'd have thought they would have similar mettalurgic properties. Unless you get a big old chunk to identify its surface and granular structure its going to be difficult to place its origin. Even with a scanning electron microscope your diagnosis wouldn't be easy. Quote Link to comment Share on other sites More sharing options...
Kranz Posted February 12, 2007 Share Posted February 12, 2007 Can you tell the difference between piston ring debris and turbo charger bearing debris in the oil? I'd have thought they would have similar mettalurgic properties. Unless you get a big old chunk to identify its surface and granular structure its going to be difficult to place its origin. Even with a scanning electron microscope your diagnosis wouldn't be easy. Yep, piston rings are chrome moly, turbo bearings are mainly bronze unless its a DBB?? The analysis is done on a spectrographic analyser (loks at the spectrum of light that is emitted as a small drop of the sample is burned) and gives a reading in parts per million for each metal and additive. Also gives levels of fuel, soot and debris in the oil. Quote Link to comment Share on other sites More sharing options...
dangerous brain Posted February 13, 2007 Share Posted February 13, 2007 Yeah I spent 5 years doing the same on chinook helicopters. For these systems to be effective you need to perform periodic sampling and profile the debris. AFAIK Jake has a DBB turbo. Quote Link to comment Share on other sites More sharing options...
Nick Posted February 13, 2007 Share Posted February 13, 2007 It's not a ball bearing turbo (post 21). Sorry to hear you're having more problems with the car. Quote Link to comment Share on other sites More sharing options...
Ian C Posted February 13, 2007 Share Posted February 13, 2007 The engine had only done about 350 since the rebuild when I got the car. I don't know what oil was in it at the time. This afternoon I took the car out to warm it up before trying a few things to diagnose the PCV but the damn thing isn't smoking now. Once it was warmed up I did a few motorway pulls and let it over-run loads of times but as far as I can tell it's fine at the moment. Looking at the oil on the dipstick, it's quite black and I'm not sure if it smells of petrol. If there was petrol in the fuel that would be a sure sign the rings are shot, wouldn't it? Isn't there somebody here who can get oil samples analysed? When I had my overfuelling problem a couple of years back, I drove about 500 miles before taking it off the road to fix it and then went through a tank of fuel mostly at idle trying to diagnose it. It was constantly running 25% rich and was a complete basket case due to a series of bad connections at the ECU and an AFC that had spectacularly failed. The oil got contaminated with fuel (and by christ I don't ever want to smell that smell again - you'd know if it had happened) but even then the ring sealing wasn't affected. Of course, it was only 500 miles and closed loop pulled it back as far as it could, just the cold start was wretched when it wasn't in closed loop and it drank fuel when I poked the throttle. However, if the car was mapped so badly it was borewashing you'd see a marked loss in power when on boost, even to the point of misfires. At idle you'd stall on liftoff and have a bad cold start. It'd be wretched to drive. Sounds like you aren't getting any of these - not got a HKS mushroom filter have you? I'm not saying it's not the rings though. I just don't know. Overrun oil smoke is a mystery. I thought it smoked on-boost? That was ages ago, but I don't recall a conclusion to it? And I'm not saying it's OK to drive a Supra with massive overfuelling either... -Ian Quote Link to comment Share on other sites More sharing options...
dangerous brain Posted February 13, 2007 Share Posted February 13, 2007 Oh I have a mushroom right now Will EGT's shed any light on this problem, assuming of course Jake has EGT gauge. Will any other onboard guages assist diagnosis? Quote Link to comment Share on other sites More sharing options...
Ian C Posted February 13, 2007 Share Posted February 13, 2007 Well I know CW has worked on at least one Skyline engine that has eroded its turbo blades and cylinder walls due to grit getting past the HKS filter. I know of another that went the same way. They are notoriously poor filters. I doubt an EGT gauge would show anything, exhaust temps will have nothing to so with this, it sounds more like load/vacuum shows it up. I guess piston rings being buggered means when in-cylinder vacuum is high, i.e. on overrun at high revs, it sucks oil past the rings. Hmm. Sounds suspiciously like what is going on but why the hell would the rings have gone so fast?! -Ian Quote Link to comment Share on other sites More sharing options...
Soonto_HAS_soop Posted February 13, 2007 Share Posted February 13, 2007 Depends if the rings were actually changed when rebuilt. Cheap bodge, but possible, heard of it happen before, although not on a soop. Quote Link to comment Share on other sites More sharing options...
paul mac Posted February 13, 2007 Share Posted February 13, 2007 Jake when i did my stem seals they were shot and i mean absolutely knackered, the exhaust side had completely lost the seal part, my car sometimes smoked on start up sometimes loads sometimes none, it did not however have the symptoms you are describing Quote Link to comment Share on other sites More sharing options...
dandan Posted February 14, 2007 Share Posted February 14, 2007 Any news Jake? Quote Link to comment Share on other sites More sharing options...
dandan Posted February 23, 2007 Share Posted February 23, 2007 ??? Quote Link to comment Share on other sites More sharing options...
Kranz Posted February 28, 2007 Share Posted February 28, 2007 I have the results back for the oil. The base engine itself is fine. No abnormal ring/cylinder wear, no evidence of fuel in oil. The copper is a tiny bit high though, sort of like thrust washers or turbo bearings?? Nothing spectacularly high at all though. If I had to *guess* what this problem was I'd say perhaps the turbo is losing oil pressure on over run???? Turbine oil seal piston ring??? Quote Link to comment Share on other sites More sharing options...
Jake Posted March 13, 2007 Author Share Posted March 13, 2007 *UPDATE* Took the turbo over to Turbo Dynamics this afternoon. The tech guy who I spoke to gave it the once-over while I was there and he reckons the thrust bearings are knackered and immediately lost me with techno-turbo-speak about ringlands and suchlike. Anyway, I've left it with them and they'll get back to me with a quote in the next few days. He also asked if I wanted the turbo upgraded at all. He recommended converting it to watercooling. He said it would help the reliability a lot. He also said they can convert it to ball bearings but he reckoned that would be up to £1000 - so that's a non-starter. Any thoughts about converting to water cooled though? Quote Link to comment Share on other sites More sharing options...
Alex Posted March 13, 2007 Share Posted March 13, 2007 *UPDATE* Took the turbo over to Turbo Dynamics this afternoon. The tech guy who I spoke to gave it the once-over while I was there and he reckons the thrust bearings are knackered and immediately lost me with techno-turbo-speak about ringlands and suchlike. Anyway, I've left it with them and they'll get back to me with a quote in the next few days. He also asked if I wanted the turbo upgraded at all. He recommended converting it to watercooling. He said it would help the reliability a lot. He also said they can convert it to ball bearings but he reckoned that would be up to £1000 - so that's a non-starter. Any thoughts about converting to water cooled though? It's not necessary...and not worth it without haveing a DBB race cartridge as well IMO. Just be kind to her warming it up and down... Quote Link to comment Share on other sites More sharing options...
Kranz Posted March 13, 2007 Share Posted March 13, 2007 *UPDATE* Took the turbo over to Turbo Dynamics this afternoon. The tech guy who I spoke to gave it the once-over while I was there and he reckons the thrust bearings are knackered and immediately lost me with techno-turbo-speak about ringlands and suchlike. Did he mean the turbine oil seal that looks like a piston ring??? If the thrust bearing is shot it'll allow the shaft to 'walk' and the compressor oil seal will then not work. Does it have a compressor carbon seal or another (labrynth or piston ring) type ?? Quote Link to comment Share on other sites More sharing options...
Jake Posted March 13, 2007 Author Share Posted March 13, 2007 Did he mean the turbine oil seal that looks like a piston ring??? If the thrust bearing is shot it'll allow the shaft to 'walk' and the compressor oil seal will then not work. Does it have a compressor carbon seal or another (labrynth or piston ring) type ?? I don't know really, can't remember much of what he said. He showed me how the shaft had axial play and mentioned something about ringlands and piston rings but it all went over my head TBH. He was only looking at it externally while I was there, they'll get back to me with the full story once it's had the full stripdown. Just got to hope it's fixable now. Quote Link to comment Share on other sites More sharing options...
dandan Posted March 13, 2007 Share Posted March 13, 2007 I'm sure they use Garrett cartridges so fingers crossed it should all be ok in terms of repair/refurb. Good luck. Quote Link to comment Share on other sites More sharing options...
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