White Smoke On Start Up

[_MRR33]

Hey,

Some of you may know that I posted a topic about a week ago, regarding a issue with white smoke coming from the exhaust, I thought I had fixed it - but obviously I haven't.

Just a quick run down on what we've worked out so far,

Once the car has been sitting for a extended period (eg: overnight and after work) the car will blow a bit of white smoke from the exhaust. If the car is warm, or hasn't been sitting for more then, say 8 hours its fine.

Spark Plugs (Iridium) and Oil (Royal Purple) have both been changed to rule out any minor issue. It's come down to two things now I think, either the turbo seals or the valve stem seals.

I'm not sure what one it is ..yet but I'm trying to work on that. Probably take the turbo off this weekend and have a look.

But, here's what a couple of different experts had to say:

A Mechanic said:

It's the valve stem seals, the fact it sits overnight etc its leaking oil while its sitting and then once the car gets warm its burning the excess smoke.

B Mechanic said:

It's the turbo seals, the fact that its sitting overnight etc, its leaking oil into the dump pipe and when the car is warm it burns it.

Whats your opinions?

[Cubes]

I had the same problem with my old rb20t.

If I were to start the car after it sitting for a good 8hrs either overnight or heading home after work and give it a quick rev I'd see a little cloud of smoke; take off only just hit boost and I'd see a small oil cloud behind me.

Changed turbo's still did it.

Apart from cold starts it never blew smoke and didn't use oil. Even when it was cold by the time I clicked third gear there was no more smoke. Next accel round it was clean.

I then dropped the RB30DET (rebuilt head) in with the same turbo; no more smoke.

So in my case valve stem seals.

My opinion is if it were turbo seals it would be doing it when warm also.

[_MRR33]

I had the same problem with my old rb20t.

If I were to start the car after it sitting for a good 8hrs either overnight or heading home after work and give it a quick rev I'd see a little cloud of smoke; take off only just hit boost and I'd see a small oil cloud behind me.

Changed turbo's still did it.

Apart from cold starts it never blew smoke and didn't use oil. Even when it was cold by the time I clicked third gear there was no more smoke. Next accel round it was clean.

I then dropped the RB30DET (rebuilt head) in with the same turbo; no more smoke.

So in my case valve stem seals.

Fair enough, I want to make sure 100% before I go spending $1500 on getting the valve stem seals done.

I was told I can take the turbo off and check the dump pipe side of the turbo for oil and leave it on its side overnight and see if any oil leaks to rule that out.

I've checked the otherside, being the side with the fins etc and that was fine, really clean and zero shalf play.

[Cubes]

I was told I can take the turbo off and check the dump pipe side of the turbo for oil and leave it on its side overnight and see if any oil leaks to rule that out.

I'm unsure if that would tell you if the turbo really is stuffed or not.

Every turbo I've had when sitting on the shelf leaks oil past the turbine wheel and compressor wheel.

My new garrett turbo did it, and 4 other RB turbo's I've had have all done it. R34 GTT turbo, 2 x VG30det turbo's 1 x rb20det turbo.

A mates journal bearing highflow also did it from new.

But regardless... You won't see any oil by doing that test anyway as it would have to fill the scroll to the height of the turbine wheel minor first. Which would be a good 100-200mls of oil at a guess.

So really I don't believe you are any wiser. If your going to have the head rebuilt get it cleaned up in the process, have a little port work done to it as it really does pay off with the 25 heads.

I had mine rebuilt, multi angle valve job, valve deshroud, inlet and exhaust port for ~$1100 from memory. BUT that was myself giving them the head and them not removing/installing it.

[_MRR33]

I'm unsure if that would tell you if the turbo really is stuffed or not.

Every turbo I've had when sitting on the shelf leaks oil past the turbine wheel and compressor wheel.

My new garrett turbo did it, and 4 other RB turbo's I've had have all done it. R34 GTT turbo, 2 x VG30det turbo's 1 x rb20det turbo.

A mates journal bearing highflow also did it from new.

But regardless... You won't see any oil by doing that test anyway as it would have to fill the scroll to the height of the turbine wheel minor first. Which would be a good 100-200mls of oil at a guess.

So really I don't believe you are any wiser. If your going to have the head rebuilt get it cleaned up in the process, have a little port work done to it as it really does pay off with the 25 heads.

I had mine rebuilt, multi angle valve job, valve deshroud, inlet and exhaust port for ~$1100 from memory. BUT that was myself giving them the head and them not removing/installing it.

Ah alright, that was quite helpful thank-you. I was told my the mechanic who said it was the turbo seals that I should do that, but I guess there's no point?

How much do you think I'd be looking at to get the head completely rebuilt?

[Cubes]

If it only does it on cold starts unless it really bugs you why bother.

Mine did it for a good 100,000km's, never got any worse.

Spend the 1.5k on some go fast mods and do the head at a later date when it cracks one of those ringlands as the rb25's almost always do at some point.

As for costs.

Highly recommended to grab the genuine nissan VRS kit for around $280. They come with all top end gaskets, seals, headgasket & including valve stem seals. I priced up the valve stem seals alone and nissan wanted $330 :S

For a valve stem seal replacement and valve grind you'll probably be looking at $300-$400 max depending on how well the bloke knows the heads. I can't remember exactly what I was charged as it was 2-3years ago but it was around that price just for the rebuild so to speak I also had bronze I think it was valve stem guides fitted.

[_MRR33]

If it only does it on cold starts unless it really bugs you why bother.

Mine did it for a good 100,000km's, never got any worse.

Spend the 1.5k on some go fast mods and do the head at a later date when it cracks one of those ringlands as the rb25's almost always do at some point.

As for costs.

Highly recommended to grab the genuine nissan VRS kit for around $280. They come with all top end gaskets, seals, headgasket & including valve stem seals. I priced up the valve stem seals alone and nissan wanted $330 :S

For a valve stem seal replacement and valve grind you'll probably be looking at $300-$400 max depending on how well the bloke knows the heads. I can't remember exactly what I was charged as it was 2-3years ago but it was around that price just for the rebuild so to speak I also had bronze I think it was valve stem guides fitted.

Thats the thing, it really bugs me - lol funny enough I just want everything running right, when you start it up cold, first 2 minutes is fine then when it starts to smoke it slowly gets more smoky until theres quite a bit of smoke in the air - I hate it.

I've only got the one quote so far, and they've said $1500 or less. I guess while the head is off I'll do what needs to be done and what should be done, since the car had the bottom end rebuilt 4-5mts ago I might as well finish it and do the top.

Thats weird, $330 for Valve Steam Seals on there own from Nissan, but the Nissan VRS kit, you get the gaskets, seals, headgaskets and the valve stem seals cheaper.

But, I'll keep you updated, thanks very much though been very helpful

Edited October 25, 2007 by KustomR33

[_MRR33]

So,

If the valve stem seals need to be done - what needs to be done to the head? and what should be done to the head while its off?

Cheers!

[Cubes]

Cams, lifters, springs removed replace valve stems.

As for what else needs or should be done really depends on what your long term goals are.

If the motors been 'built' give the head a complete reco maybe a little port work while its off, a set of performance springs valve springs and then its ready to drop a set of nice cams in it with 20-25psi of boost.

[blind_elk]

I've still got money on water vapour from the combustion process.

[Cubes]

lol yeah its most likely that.

Be 100000% sure its not Water. Oil has a completely different density/look/smell and hangs around where as water disperses much quicker.

[ak_stylez]

My friend was describing something similar for his soarer and when I had a look it was just water vapour. be sure its not that you don't wanna needlessly throw away $1500.

[benl1981]

You should be able to get the valve stem seals from ACL for about $40. Some people have had luck changing these with the head on. Search around you'll see a thread.

[Cubes]

I was told by the bloke who built the engine to make sure I get genuine nissan valve stem seals, which was based on experience with the VLT heads. :S

How do the ACL's hold up? I've managed 70,000km's and the genuine are still going strong.

[benl1981]

Can't say I've used them so maybe it is better to stick to Genuine for such a time consuming task in case something goes wrong.

[Simon-S14]

stick with genuine, as cubes said it pays to do a full head reco with some work while its off the block.

Water vapour could be a prob, either way the head has to come off anyway

[_MRR33]

If it was water vapour, what would cause that?

At stages, there becomes quite large amounts of smoke, I really want to make sure I know the problem before spending any money, like you said don't want to fork out $1500 and find out it's still doing it.

[warriorbrawl]

Hey mate-

how old /new is the turbo?

Is it the stock one?

How many kms do you think the engine has done?

this maybe be a good indicator as to what is gone.

[ZILR-34]

just reading up on this. i got the same problem with my RB20. if im goin to fork out $1500 to change the valve stem seals + reco the head am i better off getting a RB25de and bolting on turbo gear as im already make 230rwkw's ??

cheers

bill

[-_-StRyDeR-_-]

instead of spending the 1500 odd dollars... why not pull the head off yourself and give it to them to then fix up, will save urself 300-400ish in labour costs