Jump to content
SAU Community

Recommended Posts

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?

Link to comment
https://www.sau.com.au/forums/topic/190755-white-smoke-on-start-up/
Share on other sites

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.

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.

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.

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?

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.

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 by KustomR33

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. :/

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. :P

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.

  • 4 weeks later...

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

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • AHHHH gotchaa, I'll do that once I am home again. I tried doing the harness with the multimeter but it seems the car needed a jump, there was no power when it was in the "ON" position. Not sure if I should use car battery jump starter or if its because the stuff that has been disconnect the car just does send power.
    • As far as I can tell I have everything properly set in the Haltech software for engine size, injector data, all sensors seem to be reporting proper numbers.  If I change any injector details it doesnt run right.    Changing the base map is having the biggest change in response, im not sure how people are saying it doesnt really matter.  I'm guessing under normal conditions the ECU is able to self adjust and keep everything smooth.   Right now my best performance is happening by lowering the base map just enough to where the ECU us doing short term cut of about 45% to reach the target Lambda of 14.7.  That way when I start putting load on it still has high enough fuel map to not be so lean.  After 2500 rpm I raised the base map to what would be really rich at no load, but still helps with the lean spots on load.  I figure I don't have much reason to be above 2500rpm with no load.  When watching other videos it seems their target is reached much faster than mine.  Mine takes forever to adjust and reach the target. My next few days will be spent making sure timing is good, it was running fine before doing the ECU and DBW swap, but want to verify.  I'll also probably swap in the new injectors I bought as well as a walbro 255 pump.  
    • It would be different if the sealant hadn't started to peel up with gaps in the glue about ~6cm and bigger in some areas. I would much prefer not having to do the work take them off the car . However, the filler the owner put in the roof rack mount cavities has shrunk and begun to crack on the rail delete panels. I cant trust that to hold off moisture ingress especially where I live. Not only that but I have faded paint on as well as on either side of these panels, so they would need to come off to give the roofline a proper respray. My goal is to get in there and put a healthy amount of epoxy instead of panel filler/bog and potentially skin with carbon fiber. I have 2 spare rolls from an old motorcycle fairing project from a few years back and I think it'd be a nice touch on a black stag.  I've seen some threads where people replace their roof rack delete with a welded in sheet metal part. But has anyone re-worked the roof rails themselves? It seems like there is a lot of volume there to add in some threads and maybe a keyway for a quick(er) release roof rack system. Not afraid to mill something out if I have to. It would be cool to have a cross bar only setup. That way I can keep the sleek roofline that would accept a couple bolts to gain back that extra utility  3D print some snazzy covers to hide the threaded section to be thorough and keep things covered when not using the rack. 
    • Probably not. A workshop grade scantool is my go to for proper Consult interrogation. Any workshop grade tool should do it. Just go to a workshop.
    • In my head it does make sense to be a fuel problem since that is what I touched when cleaning the system. When I was testing with the fuel pressure gauge, the pressure was constantly 2.5 bar with the FPR vacuum removed. When stalling, the pressure was going up to 3.0 bar (which is how it should be on ignition).
×
×
  • Create New...