White smoke on deceleration...

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Supra

New Member
May 11, 2005
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Re my new motor:
http://www.supramania.com/forums/showthread.php?t=19395

My GF was following me the other night and commented that 'when I passed a guy, my car's exhaust was clean, but when I was done passing him (when I let off the gas) there was a puff of blue smoke'. I hadn't noticed this but now that I'm paying attention to it, there is a light to moderate puff of blue smoke when I let off. It seems worse when I run 15psi of boost (highest yet), let off and coast with the car in nuetral or up shift creating minimal vaccum. If I boost and then decel. in gear (high vaccuum) it doesn't smoke, or there's very little smoke which is why I probably never noticed it.

I'm betting the rings aren't seated, but I have 1,050 miles on the motor now. Should I be concerned or is the motor still breaking in?

Break in so far has been:
0 miles - 30W Valvoline new oil filter
0-5miles - new oil filter
5-100miles - 10W40 Castrol new oil filter
1,000- miles - 10W40 Castrol new oil filter

I was generally easy on the motor for the first 200 miles, then I beat it pretty good with hard decel. I'm wondering if the rings still have a chance to seat after 1,000 miles. Absolutely no other run problems and the plugs looked good after 500miles.
 
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Supra

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drjonez said:
what's the PCV setup?
Click to expand...

This is the first time I'm running a catch can. If you DL the video from my rebuild thread, it's very clear what i have but in simple terms it's the stock PCV pipe cut off, then a ~1/2" hose from there to the catch can. Then from the can down to the ground. Catch can itself is a generic that has 3/8" ID in/out with no check valves. I thought it would suffice.

Should I run a long hose from the PCV to the ground to bypass the can and do a couple runs? :1zhelp:
 
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dbsupra90

toonar
Apr 1, 2005
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indiucky
IJ. said:
Probably just a case of you need some vaccum to scavenge the blowby.
(not enough flow at atmo to keep up)
Click to expand...

yep i agree. it works a lot better running it to the intake tube instead of road draft.
the rings should have seated by now. 15psi should have taken care of that. if not run 30psi just to be sure ;)
 
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Supra

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I'll get a nipple welded to the AL intake pipe as soon as possible. See if that cures the problem. Any longer term effects from this or should the smoke clear up?
 
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drjonez

Supramania Contributor
Mar 31, 2005
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www.4cefed.com
no probs doing that, provided the catch can can condense out the oil....

running it that way puts a bit of vac on the crankcase, pulling blowby out and helping the rings seal better....
 
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Supra

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May 11, 2005
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I re-routed the catch can to the intake and the problem hasn't changed. :3d_frown:

Also checked the turbo for shaft play (OK). It seems like the more boost pressure I run, the worse it is when I let off. Doesn't do it between shifts though, only about 1-2 secs after I let off from a hard, WOT run.

I'm going to view the problem from another car to get a first hand look at if it's coming from the tailpipe and what color it really is. It certainly looks blue from in the rearview mirror. I plan to do a compression check tonight and see if the numbers look good. Check the PCV catch can for flow and try directly running the PCV line to the intake (bypass the catch can). :3d_frown: :3d_frown: :3d_frown:

Other than this 'problem', the car is running great! No misfires, no overheating and builds boost fast. (Knock on wood) :love:
 
mkiiSupraMan18

mkiiSupraMan18

Needs a new username...
Apr 1, 2005
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-Rich87Tx2 said:
(Knock on wood)
Click to expand...

Why would anyone menton knocking on anything around a 7m? :icon_conf
I'm just curious to see how things play out for you, incase I have this prob or something similar w/ my rebuild.
 
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Supra

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May 11, 2005
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bensn8 said:
It could be bad seals on your turbo, When you checked for shaft play I bet you checked on the intake side. Remove the elbow and check for any oil.
Read this. http://www.supramania.com/forums/showthread.php?t=19394
Click to expand...

Doesn't matter which side you check from. It's the same shaft. :icon_razz If you're leaking oil to the elbow, I would think that it's going to slow burn leaving a long cloud trail.

I have a sharp *POOF* of smoke a few seconds after letting off that literally leaves a small "wall" of smoke. The kicker is that if I go WOT but shift 'slow' it does NOT smoke at all. I have to actually let off and then wait a full 1-2 secs then it lets out a *poof*.

I just got back from a long week of travels so I'm finally starting to trouble shoot it. The motor has 1,100 miles now with no run problems other than this annoying puff of smoke.

I still need to follow the car and see the problem from behind. Last night I would have swore that it gave a quick, potent puff of blue smoke (twice, separate runs). This morning I boosted and I would swear that it gave a sharp light gray puff. :nono:

Problem is not getting worse, and it's not getting better. I might just pay to set it on a dyno for an hour. :3d_frown: It'll be easier to troubleshoot that way.
 
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Supra

New Member
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LOL, how's this for luck. Blew a second coolant hose today. One of a handful that didn't get replaced during the rebuild and it looks pretty old, probably shouldn't have re-used it. It's the one under the T-stat this time. I was boosting, got the same cloud only bigger this time and then I smelled that sickly sweet smell that all MKIII owners know so well. I'm wondering if this was the cause of my "questionably blue smoke"??? Guess we'll find out tomorrow... :3d_frown:

I'm going to have nightmares about cylinder pressure entering the cooling system and popping ALL my hoses. BHG!!!! NOOOOOOO!!!!!! :biglaugh: :biglaugh: :cry: :cry:

Owned and stranded at work by a $0.99 hose. Priceless.
100_0389.jpg
 
nickel and dimed

nickel and dimed

Member
Aug 13, 2005
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Alberta
MDCmotorsports said:
Rich:
Have you tried another air filter? Possibly one of larger volume or better quality?

Just a thought... cheap filters will create vacuum and cause oil comsumption.
Click to expand...

This is news to me. Could you explain where and how a cheaper filter could do this?
 
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