Whatskid Posted January 28, 2014 Share Posted January 28, 2014 (edited) As title states I've finished an rb25 conversion into my 32 rebuilt with cp forgies about 5k ago when I bought it, oil is visible ontop of cyl 4 and blows smoke under throttle so I pulled the head off had it flow and leak tested to show worn valve stems seals and guides, wasn't financially able to pull the bottom end apart at the time Running catch can, cut and shut forward plenum 1200cc inj 3076r Whilst the head was off we checked for cracks in the block, wear marks on the bore and movement in the pistons and all was mint Just had a brand new hg and reco neo 25 head dropped on, so can't be valves/seals Compression tested and pulled 174-180 across all 6 with the leaky cylinder sitting at 175 Turbo was fresh rebuilt by gcg and currently done about 0.1km's no sign of oil burning anywhere, none in the cooler piping I couldn't see it being a bad oil ring/good compression ring because of the rebuild and cp aren't that bad of a company, but at the same time I could be wrong Possibilities of it being a pinched ring from not being set right during the build ? There is oil in the plenum but not a crapload The only other thing I know about is there's a small piece missing from the pcv o ring but it still seals and doesn't seem to leak it's getting tuned in a few weeks regardless of it's shitty issue cause 6 months in a mates shed is becoming too much Will be ripping it down again after that, just seeing if anyone can shed some light Edited January 28, 2014 by Whatskid Link to comment https://www.sau.com.au/forums/topic/438346-25det-blowing-smoke-shed-some-light/ Share on other sites More sharing options...
89CAL Posted January 28, 2014 Share Posted January 28, 2014 What oil pump, what oil and any oil control (restrictors etc) fitted? Link to comment https://www.sau.com.au/forums/topic/438346-25det-blowing-smoke-shed-some-light/#findComment-7182862 Share on other sites More sharing options...
sonicz Posted January 28, 2014 Share Posted January 28, 2014 (edited) Cant help but I'll be interested to see what it turns out to be since I've been having a similar problem for about 6 months now. My 25det never used to use up any oil then suddenly over night it started to emmit a dry burnt smell from the exhaust constantly at idle accompanied by a tiny amount of smoke under boost. But this adds up to about loosing 1L of oil in 1000k. Did a compression test all 6 were 150psi, but my battery was dying and when i done it with a new battery it got close to 170. Some mechanics said its probably oil control rings but no way I have the money for a rebuild on a guess. Normal tiny amount of oil in intercooler pipes as well. Does it with any oil, but obviously slightly less with thicker oil. no mods or catch cans stock oil pump Edited January 28, 2014 by sonicz Link to comment https://www.sau.com.au/forums/topic/438346-25det-blowing-smoke-shed-some-light/#findComment-7182890 Share on other sites More sharing options...
Leeroy94 Posted January 28, 2014 Share Posted January 28, 2014 Black smoke or white smoke? Link to comment https://www.sau.com.au/forums/topic/438346-25det-blowing-smoke-shed-some-light/#findComment-7182892 Share on other sites More sharing options...
Whatskid Posted January 28, 2014 Author Share Posted January 28, 2014 (edited) What oil pump, what oil and any oil control (restrictors etc) fitted?Stock pump, no restrictors fitted that I'm aware of other than oil feed for the turbo, and running hpr10 through it. Black smoke or white smoke? Light blue Edited January 28, 2014 by Whatskid Link to comment https://www.sau.com.au/forums/topic/438346-25det-blowing-smoke-shed-some-light/#findComment-7182967 Share on other sites More sharing options...
Ben C34 Posted January 28, 2014 Share Posted January 28, 2014 When does it smoke? The oil on top of one piston, coupled with slightly lower result on that cylinder is concerning. Link to comment https://www.sau.com.au/forums/topic/438346-25det-blowing-smoke-shed-some-light/#findComment-7182968 Share on other sites More sharing options...
Whatskid Posted January 28, 2014 Author Share Posted January 28, 2014 When does it smoke? The oil on top of one piston, coupled with slightly lower result on that cylinder is concerning. Under throttle, I rev it, it puffs smoke But it takes a small period of time to build up to it the longer I leave it on idle the more it does it I though the same too, but it still had a higher psi than number 2 and on par with 6 Both have no issue, from general experience they should all be no less than 14psi less than the highest reading. Link to comment https://www.sau.com.au/forums/topic/438346-25det-blowing-smoke-shed-some-light/#findComment-7182971 Share on other sites More sharing options...
Leeroy94 Posted January 29, 2014 Share Posted January 29, 2014 I would suggest posting a photo of your engine bay. I rebuilt a turbo daily and it was having similar problems. Turned out there was an air breather on my rocker cover that acted like a valve, but it was installed backwards, causing my engine to puff smoke similar to when yours does. Link to comment https://www.sau.com.au/forums/topic/438346-25det-blowing-smoke-shed-some-light/#findComment-7183151 Share on other sites More sharing options...
Whatskid Posted January 29, 2014 Author Share Posted January 29, 2014 I'll have to get a shot up tonight, I'm pretty sure I didn't miss anything during the build Link to comment https://www.sau.com.au/forums/topic/438346-25det-blowing-smoke-shed-some-light/#findComment-7183275 Share on other sites More sharing options...
Whatskid Posted January 29, 2014 Author Share Posted January 29, 2014 Link to comment https://www.sau.com.au/forums/topic/438346-25det-blowing-smoke-shed-some-light/#findComment-7183578 Share on other sites More sharing options...
WMDC35 Posted January 29, 2014 Share Posted January 29, 2014 must be the bottom end if the head has been eliminated?, do you know if they rebuilt it because it failed, maybe on the same cylinder? Link to comment https://www.sau.com.au/forums/topic/438346-25det-blowing-smoke-shed-some-light/#findComment-7183642 Share on other sites More sharing options...
Whatskid Posted January 29, 2014 Author Share Posted January 29, 2014 must be the bottom end if the head has been eliminated?, do you know if they rebuilt it because it failed, maybe on the same cylinder? Previous owner tried to run 340rkw through a stock bottom end, which I saw the aftermath of what's left in the shed, so had this one built I've been leaning to the bottom end too, it's generally the number 1 thing but that doesn't explain how oil can be in the plenum but not in the piping or cooler etc Link to comment https://www.sau.com.au/forums/topic/438346-25det-blowing-smoke-shed-some-light/#findComment-7183687 Share on other sites More sharing options...
Ben C34 Posted January 29, 2014 Share Posted January 29, 2014 As you seem to only have oil in the plenum, I would try disconnecting the pcv line to the plenum and seeing what happens. It could be faulty. Link to comment https://www.sau.com.au/forums/topic/438346-25det-blowing-smoke-shed-some-light/#findComment-7183759 Share on other sites More sharing options...
Whatskid Posted January 29, 2014 Author Share Posted January 29, 2014 As you seem to only have oil in the plenum, I would try disconnecting the pcv line to the plenum and seeing what happens. It could be faulty. That's the next spot, I'm waiting on cooler piping to be welded up, hopefully pickup today Then I can tinker again Link to comment https://www.sau.com.au/forums/topic/438346-25det-blowing-smoke-shed-some-light/#findComment-7184030 Share on other sites More sharing options...
WMDC35 Posted January 29, 2014 Share Posted January 29, 2014 could be from breathing hard, could try blocking the pcv but would maybe need a breather on the catch can, that plenum may not be helping with engine lifespan Link to comment https://www.sau.com.au/forums/topic/438346-25det-blowing-smoke-shed-some-light/#findComment-7184031 Share on other sites More sharing options...
Whatskid Posted January 29, 2014 Author Share Posted January 29, 2014 could be from breathing hard, could try blocking the pcv but would maybe need a breather on the catch can, that plenum may not be helping with engine lifespan The plenum itself isn't that bad, the inside of it was reshaped and welded similar to a greddy Once the motor etc is engineered I'll be going for a plazmaman Link to comment https://www.sau.com.au/forums/topic/438346-25det-blowing-smoke-shed-some-light/#findComment-7184042 Share on other sites More sharing options...
sonicz Posted January 31, 2014 Share Posted January 31, 2014 Why dont you stick a boroscope in each cylinder and see whats going on in there? Link to comment https://www.sau.com.au/forums/topic/438346-25det-blowing-smoke-shed-some-light/#findComment-7185618 Share on other sites More sharing options...
Ben C34 Posted January 31, 2014 Share Posted January 31, 2014 Cos you can't see damaged ringlands or worn rings. I seriously doubt it's a scored bore. And anyway, he had the head off so had seen the condition of the bores. Link to comment https://www.sau.com.au/forums/topic/438346-25det-blowing-smoke-shed-some-light/#findComment-7186074 Share on other sites More sharing options...
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