smoke when comin off boost

[BeRad]

yer ok, how do u know that turbo isnt rooted as well?

[BeRad]

u can borrow my old ct26 if u feel the urge to f**k around changing them haha

[-==L=a=N=c=E==-]

since this rebuild had forgies put in. Did they get the piston to wall clearance right?

it could possibly be turbo seals?

[sleeker162]

RICHARD, did u get my email?

[o_man_ra23]

Spoke to my engine builder about this over a couple of johnnys just then. Smoke is normal after 400km as the oil is thin and will be washing the bores, but inherantly also burning during combustion. Changing the oil would be a step in the right direction, as this will usually fix the problem, and now is about the time you should do it. I have heard of fresh motors going really smokey around 400k quite a bit, and just being all the grit from the rings bedding in that killed the oil, as such, oil change was what the doctor ordered. I wouldnt take it back to them until after i change the oil... save being told to change the oil by them, and then look like a dick when that fixes it.

HPR5 was just a suggestion as it is suited to modern high revving turbocharged engines. HPR15 is also a great oil, and is better suited to hot climates, but will increase the force required to spool up the turbo, generating extra lag. Try the HPR15 first, and later you may wish to experiment with the HPR5 etc. your decision on that really.

Saw a brand new holden tigra the other week blowin smoke out cause the motor was new and not run in... so its not that worrying during the first 1000km to see smoke, and if your first run of oil is 400km old, i would be expecting to see plenty of smoke.

Cheers, Owen

[sleeker162]

thanks owen

[-==L=a=N=c=E==-]

RICHARD, did u get my email?

where'd you send it too....? i havn't seen it yet.

[YLD-16L]

Spoke to my engine builder about this over a couple of johnnys just then. Smoke is normal after 400km as the oil is thin and will be washing the bores, but inherantly also burning during combustion.

The amount of smoke this guy is having sounds like more than is seen from some freshly built engines.

I have heard of fresh motors going really smokey around 400k quite a bit,

I haven't (but not to say it isn't possible ) and the only smokey engines I have seen are either old, built poorly (incorrect piston clearaces and ring gaps, or valve stem seal problems) or have turbos with seals that are letting oil into the exhaust housing (numerous reasons are possible for this which I won't go into).

This guy as many have already said is either running a fubar turbo (just because it was changed doesn't make it a good one) or the engine was built like crap.

Simply eliminate the possibility that it is the turbo or the oil being too thin (due to the running in process as o_man_RA23 mentioned) and then go back to the engine builder and get it sorted.

[o_man_ra23]

Smoke is caused by gaps between the rings and bores allowing oil to run through into the combustion cycle. when rings are first put in bores, they are not a perfect fit, which is why you wear them in during the run in(otherwise known as wear in) cycle. the gaps which it creates from not being a perfect seal will allow oil through. since run in oil is thin, it will get through these gaps easier, causing more smoke. Because of the grit that the oil is in constant contact with, and combustion processes coming slightly into the crank case, the oil wears out very quickly, and at around 400km is quite thin, and getting very close to useless.

The other possibilities are quite valid, that the turbo is a dud, or the build was crap... but im just thinking that maybe each possibility should be ruled out one at a time, starting with the quickest, cheapest and easiest... the oil.

Cheers, Owen

[-==L=a=N=c=E==-]

it possibly isn't the bottom end. Could it be valve stem seals? Since from memory i don't think he got the head rebuilt.

[Nim]

LOL.. mechanic time 'cos if you take it to a mechanic they make everything better

I meant take it back to the mechanic that did the build.

[o_man_ra23]

http://zhome.com/ZCMnL/PICS/turboCha...gerBasics.html

This has a pretty good explaination... how long did you idle the car for?? It reckons that excessive idling can cause a vacuum in the exhaust turbine, which will make it suck from the bearing, where the oil is, and kill your oil seal, spewing oil through your exhuast. Thatll make it smokey. Also by stopping the air from entering in the first place by shutting off the throttle suddenly, that will create a vacuum in the exhaust side wheel unless there is a plumback BOV. So if you have a vented to atmosphere or no BOV, you may wanna look at hooking the original plumback back up. This will stop the turbine wheel from creating a vacuum when going off boost, which will in turn stop it from sucking oil from your bearing. Another cause of this is possibly a clogged oil return line which can be caused by a hot shutdown... though this would normally cause both bearing seals to fail and oil to enter the intake aswell.

Cheers, Owen

[mic*]

so wjhy haven't you taken it back to the engine builder yet?

if you payed someone to do it for you.. and you are unhappy with the result.. take it back and demand it be fixed.

your engine builder should have told you the run-in procedure also....

take it back to them, ask them what is wrong and why the motor they built sucks.. and then ask them about run-in procedure (if they hadn't already told you )

Response warranted here...

[RPM016T]

If i was you I would take your car to a qualified turbo technician/salesperson and have them skope it out. I had exactly the same problem and explored every other option except this and I could have solved the problem a lot sooner and cheaper if I had gone down this path. They've delt with 1000's + oil smoke issues, chances are, anyone on the forums have probably only explored 5+ problems. No offence fella's, I just know how annoying this problem can be.

[o_man_ra23]

If i was you I would take your car to a qualified turbo technician/salesperson and have them skope it out. I had exactly the same problem and explored every other option except this and I could have solved the problem a lot sooner and cheaper if I had gone down this path. They've delt with 1000's + oil smoke issues, chances are, anyone on the forums have probably only explored 5+ problems. No offence fella's, I just know how annoying this problem can be.

I dont think anyone on the forums(unless they are a turbo technitian) would take offence... and it is sound advice, after gaining more info from sleeker. Turns out there is no oil whatsoever in the intake ducting, so that rules out pcv and compressor seal failure. Im yet to find out from him what the plugs are like. If they are oily, then it could well be a ring failure. If not, then it could be turbine bearing seal. He has also stated that the oil pressure relief spring was changed by the builder under the builder's own decision for a heavier one to allow higher oil pressures. This could well play havoc with the oil sealing of a plain bearing turbo.

Cheers, Owen