Smokey Motor - Compression reads perfect

[MR 1JZ]

Hey guys...quick one...

The motor in my suzuki has developed a smoking problem...under load it blows a bit of blue/white smoke and it is burning oil

I have done a compression test and its come up perfect 185 in all cylinders (built high comp motor)

the person I bought it off said that it had an old VRS kit put through it when it was built and the valve stem seals were not up to scratch...my experience with worn VSS's has usually shown a bit of smoke on decel and startup...do they get to the point where they chuff through the oil when they are bad?

Havent done a leakdown (dont have a compressor)
Tried thicker oil and that made it better but the car a fair bit slower
comp test was done dry

[trd_st184]

Hopefully I'm close to the right answer, but you can still have a decent compression test which would mean that the compression rings are still in good nick, but the oil rings could still be shot.

My MR2 when I first bought it used to blow smoke on cold start, but that has all disappeared now. My car hadn't been driven in about 1.5 years.

[MR 1JZ]

Hmmm...that doesn't sound good...

Is there any way to check where the oil is coming from?

[maccac__1590]

its not your rocker cover breather? or do you run a catch can? but with good compression i wouldn't have thought there would be enough blow buy to make it blow smoke

[MR 1JZ]

I don't run a catch can but I'm thinking that maybe I should set one up on it

[Omegaman]

I would think your Valve stem seals are the problem. if it were rings they would blow smoke most of the time, so since comp is good.
Try checking head gasket. Oil in radiator, will go white.

[MR 1JZ]

It does blow smoke all of the time though...that's why I'm concerned

[BLK_20v]

Had this prob with a couple of 20v engines lately... Good compression, but chewed through oil like no tomorrow.

Leak down tests can also be a little inconclusive as the last one I had a problem with was 5-10% leakage, yet the valves were wet and it'd use 1L of oil per 500kms. Didn't matter if i babied it or booted the crap outta it.

Your best bet is to get it inspected with a borescope, takes a competent mechanic about 15-30 minutes to complete the inspection.

[MR 1JZ]

sounds like I need to get a borescope onto it then...is that some sort of camera for the bores?

[RPM016T]

why dont you door knock your neighbours and see if any of them have a compressor?

[beerhead]

Valve stem seals normally leak under change of vaccum, so when you go from wide open throttle to shut, you'll get a puff of smoke. Sounds like the bores are glazed or an oil ring is had it. I've seen the ajax powder trick unglaze bores in the past, might be worth a shot if the borescope reveals no score marks from a damaged ring.

[andrew_mx83]

wet test.



edit: 185 is not that much for a high-comp motor. i usually see 200+ dry
and id say if the bores were glazed it would have been burning oil since day 1.

[MR 1JZ]

why dont you door knock your neighbours and see if any of them have a compressor?

because most of my neighbours are coons without cars let alone a shed full of tools...there is this one bloke though

thanks beerhead...that sort of answers my question...I wanted to know if valve stem seals would result in smoke on WOT

is there any way to check for a damaged oil ring without pulling the motor apart? or is that what the borescope is for?

[Shakotan_Aaron]

WOT+revs you get a lot of oil in the head, i used to find when i flogged/revved my old bus hard it would puff a bit of oil smoke. i put it down to the revs revs pulling a lot of oil in the head then the blow by helping to push it threw the breather and back to the intake. would take a good 3rd gear pull to do it as it would need a few seconds at +6k.

if its this then obviously a catch tank will stop it. i never bothered, i couldnt be bothered and i didnt really care.

[mick08]

Hey guys...quick one...

The motor in my suzuki has developed a smoking problem...under load it blows a bit of blue/white smoke and it is burning oil

I have done a compression test and its come up perfect 185 in all cylinders (built high comp motor)

the person I bought it off said that it had an old VRS kit put through it when it was built and the valve stem seals were not up to scratch...my experience with worn VSS's has usually shown a bit of smoke on decel and startup...do they get to the point where they chuff through the oil when they are bad?

Havent done a leakdown (dont have a compressor)
Tried thicker oil and that made it better but the car a fair bit slower
comp test was done dry

how many klms and what motor are we talkin?