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What Do You Think Ive Done To My Engine?


Tangles
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After help with diagnosis.

Had a track day on 11th April, track car was not ready so couldnt pop the cherry with my rb26dett sedan track car. Wasnt happy.

Took the stagea out for the day to mallala for the 4th time, always said I wouldnt run my road car there again but had no option in this instance (paid fees, couldnt waste the $)

Started the day with around 5.5L oil in engine.

Right at the end of the 2nd session (20mins each session) at the end of the straight on deceleration (as soon as foot came off accelerator) there was a MASSive cloud of grey-white smoke out the exhaust. Big smoke ball.

Get onto 1psi boost and smoke everywhere again.

Emptied catch can, cleaned oil up from engine bay, tried again next session but as soon as positive boost pressure was made smoke billowed out the exhaust again. Called it quits for the day. On the drive home anytime it reached 1psi smoke was clouding out the exhaust. Oil could be seen spraying out the T3 housing where the exhaust manifold meets the turbo. I thought "turbo oil seals" so took the turbo off. I had the turbo checked out by the manufacturer (Adelaide turbo services - ported nissan comp cover, avo .73ar rear housing, gt3076IWBB chra) but they said it checked out perfectly fine. There was oil through the air filter, and throughout the intercooler piping, cooler had a few hunded ml's of oil in it. Even the throttle body had oil pooling inside.

So, its not the turbo. There is no milkyness to the radiator fluid, nor to the engine oil. So that probably excludes the Cometic 87mm 1.1mm MLS headgasket being the problem.

Since I changed the oil & water (after turbo removal/reinstallation) there is no more smoke billowing out the exhaust on positive boost pressure.

However, the engine is leaking oil onto itself and burning as soon as it gets a little warm, it stinks of burnt oil. Smoke comes out the engine bay. The engine block has oil residue all over it, everywhere. Upon shutdown oil drips for a little while creating a small pool underneath the engine on the ground.

Just had a proper comopression tester kit delivered today, so tomorrow will comp.test the engine, in the meantime what do you think Ive broken?

Im thinking out on the track far too much oil got stuck in the head, couldnt return to the sump, and found the weakest point to escape.

Would this be the rocker cover gaskets? What / where should I start checking?

So, in a nutshell, oil coming out of engine when warm, burning on engine, stops leaking once engine is cool. What gaskets should I be checking?

Waiting on track car to be tuned and finished, then will swap stag for track car and have mechanic check it out. If I could fix it I would but not sure where to start.

If oil was stuck in the head and needed a way out - where do you think it would escape from?

cheers for any thoughts, post up your diagnosis.

ta

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Ouch, Brendo, not good to hear...

Have you checked all over the block to see if you haven't punched a hole in it somewhere? If there is oil spraying everywhere, try and see where it's spraying from, then shut the engine down and feel around the block (assuming it's not too hot to touch, of course!). If it's also coming out the exhaust, then maybe you've blown a piston ring or cracked a piston itself.

:( Best of look with finding out what it is.

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Sounds like a ring/piston prob. I would try a compression test. If you have a stuffed cylinder this should show it.

Not necessarily so but if you have delaminated the timing belt it is possible the valve train is up its FO. This recently happened to the 25G. The tensioner pulley seized. If the motor is not Knocking or rattling it should be, I hope, not too much of a drama to fix.

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yes, Ive thought originally cracked piston or turbo seals.

Could be piston crack.

Oil was spraying out the T3 housing after the event.

Will comp.test tomorrow and see if i can find the leak. Problem is the bottom end is covered in oil residue, so its hard for me to diagnose.

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its obviously just leaking out of sumwhere small once the oil thins out... i had no smoke when i had a crackd piston for sum reason. but if oil is getting into your cooler... it would have to be getting past the intake side of the turbo??

where as engine internals failing wd cause smoke burning very badly...

tangles mate id hate to say it but i think the engines coming out!

i know your more than keen to do it but may struggle with the knees and patience lol

run a comp test

try and think between the forums how oils getting to the cooler if the turbos fine

what boost did it hit after the issues ? just 1 pound of did u stop once there was smoke?

what boost were u running

what bov do u have? stock?

any reason u may have leaned off on the track? fuel pumps fine? no hoses split or ne thing.

u might be best to start haggling the guy with the rs4 engine in the stag section at the moment and just transplant!

arnt u internaly forged anyway>>

sorry for all the questions :)

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stock bottom end, everything else is aftermarket.

at the track the fuel tank was to the brim, probably over filled the engine with oil TBH, boost was set to 1.2 bar... definately NOT the turbo.

havent boosted past a cple psi since turbo re-install - havent been driving it.

definately going to leave it at the mechanics, asap.

comp test tomorrow; will report back. will put the car back up on front stands and idle the engine till hot & visually check for leaks.

oil was being forced out the t3 housing when blipping the throttle (on the track day when it happened), but not sure what that means (isnt turbo oil seals - been checked and turbo given seal of approval). got to check some more I suppose (not a fan of leaving an engine idling away for 15mins..... but will do) to find the source area.

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what sort of catch can set up do you run? does it breathe back into the intake?

Best bet would be to clea the motor down, clean out your intake and reset the oil level, then retest.

if ya wanna shoot it down here to aldinga one morning we can throw it in the hoist and have a suss.

But to be honest it sounds like something small has gone wrong.

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I got that in my Stagea after a long burst at 6k revs. At best it is the RB thing of pumping too much oil up into the head - at worst broken ring lands. When you have cleaned it all up does it seem to drive OK? Compression test will help. Seems you need the oil restrictors and cleaned out/extra oil drains to fix the problem.

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Hope everything work's out OK....hopefully something cheap and easy....sound more like a piston ring or slight melting! comp test will tell!

Edited by Jetwreck
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if not already mentioned here.. or corrected..

was there oil in the manifold/turbo hot side? if no move away from crack piston ring etc. and look elsewhere..

if there is however. you could more than likely be looking at ring/piston land broken.. i did this on my gtr once. any positive boost and loads of smoke. took rear turbo off and was coated in oil in exhaust housing. same with manifold #6 runner.

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thanks for the replies so far, made me do a comp test just now. (yesterday wasnt up for it)

I tried a cold-start dry compression test, turning over the engine for 10 cycles.

bore #1-4 + #6 showed around 80psi dry/cold

bore #5 showed 0

turned over engine for 18 cycles for #5 and showed around 35psi dry/cold

could tell from the spark plug prior to comp.test that piston 5 was not right. strip down time.

As for oil in the manifold, yes it spat out (got heslo in the glasses actually on the track day after Id cleaned the catch can) from the t3 housing where turbo meets exhaust manifold. no oil to be found in the turbo exh.housing, didnt check the exhaust manifold; was dry. got an after-market exhaust manifold to get installed that Ive had here for a few years, plus an apexi multichecker unit..... get these installed and the bottom end sorted.

So, piston melt or ringland..... sparkie #5 looked relatively 'clean' compared to the other spark plugs, which showed normal combustion deposit/useage.

cheers all. either re-ring piston 1,2,3,4&6 and use a replacement stock piston with new rings for #5, or depending on the damage to bore RB30 replacment block perhaps?

if she's bad inside it'll be RB30 time, got the head for it. I trust the head is good internally as it was worked over significantly a while ago. Ported/flowed, new valve seats/seals, poncams & hd cam springs. Uses the tomei oil restictors but the oil drain from head to sump is stock. We'll see what the damage is in good time.

The track car is being stock-tuned right at the moment ready for run-in. simply going to leave the stag at Boostworx and take the trackie for a while, using the unregistered permit system say once a fortnight to get around for a cple days (mechanical work surely means food shopping, no?), running in the fresh rb26dett ;) Being winter me & my knees arnt up to the job of engine out at home. Have to leave it for a while with my mech Shaun Dunns I feel, will be off road for a while.

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Bugger! Sorry to hear that Brendan :( Was really hoping it'd just be something small. Hopefully the rebuild doesnt cause too many headaches.

P.s, Im sure a mechanical work only permit includes trips to the local IGA :P

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did ya try a bit of oil in each cylinder and then retest, just to make sure it's pistons and not the head?

ps if ya need a hand with anything- mechanical or otherwise, yell out. i live local to ya anyway, and i don't mind helping out a fewllow stag owner if need be :thumbsup:

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thanks for the well wishes.

I'll probably try a warm compression test (new sparkies in, charging battery at the moment) later today.

afaik piston #5 is farrk'd so it's probably best if I leave it with the experts. my house is for sale atm since the split last august, so I really shouldnt be thinking about doing anything further to the car myself. leave it with my mechanic and take it slowly, no hurries no rush.

bed in the rb26dett hcr32 sedan.

17" mags, 235-45 ku36 tyres

single piston stagea rear brake setup, qfm a1rm track pads, speed bleeders, braided lines

4-piston wilwood superlite 324mm front brake setup, wilwood track pads, speed bleeders, braided lines

new coilover suspension, fully adjustable. camber arms, bushes, etc. half cage, bare interior.

various guages. Power-fc + hand controller, Bride brix seat on extra-long rails, 320kmph tomei dash.

rebuilt rb26 turbos, hks dump pipes, obx manifolds, obx two-into-1 front pipe 3.5", 3" decat pipe, 3" 5Zigen catback exhaust.

gtr in-tank fuel pump, external 305Lph fuel pump, fuel surge tank, braided lines, 550cc siemens deka injectors, yellowjacket coilpacks.

52mm dual-core alloy radiator, ati harmonic balancer, pulley kit, n1 water pump, hks oil pump, tomei oil restrictors, tomei sump baffles,

mines head baffles, greddy R34 cams, hks camshaft springs, adjustable cam gears, flowed & reconditioned head, oil return to sump system,

87mm MLS head gasket, full cometic gasket kit, block bored & sleeved, stock rods, arp bolts, 87mm cp pistons, balanced crank, jun crank collar

.................... etc

;)

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