whitish/grey smoke on startup for a couple seconds only

[Dr. Jeckel]

I just got through putting everything back together and breraking the cam in today. I noticed after I turned the car off and let it sit for a few minutes, then went to turn it back on that for a couple seconds it would smoke. It doesn't smoke at any other time. There are no leaks and the exhaust doesn't smell sweet or like oil. The heads had new valve seals put on them at the machine shop. The cam, heads,THDP, 50's, chip, rollermaster, lifters, pushrods, cometic HG's are all new. Everything was put on as per a well known engine builder on this site, who is very familiar with TR's. I also bought a pcv catch can from AMW, everybody has had good luck with it. The car runs great although I have not taken it for a full run yet. Just part throttle to about 8psi and all felt great and smooth with no smoke. I have only driven it for about 25 miles after the 30 minute breaken that comp cams recommended.
Could the smoke be the new valve seals or running a little rich from the 50's?
Car idles and runs smoother than before the cam, Thanks Eric!!

Any input is greatly appreciated.

Thanks, James.

 

[Dr. Jeckel]

It's almost like when you start your car when its real cold outside. It's very light and not dense at all.

Anybody have any ideas?

 

[Dr. Jeckel]

There are tons of experienced engine builders and the like who I am sure have an idea of what could be the cause.
Please give me some advice or explination/speculation to what might be causing the smoke. I have read and it seems the valve seals on the intake or valve guides on the exhaust valves might be the cause.
When I had the heads done they said the valve guides were good and they installed new valve seals.
Should I be real worried as it doesn't affect idle or driving characteristics? I have got the car to about 13psi during part throttle and all was great.

Anyone with experience, please lend me some advice.

Thank you, James.

 

[turbojimmy]

Can't help you - sorry. My brother's car has the same exact problem except he gets a bit more smoke than you. I posted here and on other boards and haven't gotten much help other than valve stem seals. We're going to change them this weekend. My brother's smoke is clearly blue/gray though (oil).

Usually white smoke = water; black/gray smoke = fuel; bluish smoke = oil. A little white smoke as the car idles before it warms up is usually fine. Water is a by product of combustion and it all doesn't get burned off until the engine is hot.

Fuel-smoke can be caused by an injector leaking down as it sits.

It seems that oil smoke when the engine is cold can't really come from much other than valve stem seals or rings. A bad turbo won't smoke until it's hot enough to start burning oil (which happens quickly after a cold start but not immediately at start up). The smoke my brother's car has happens when the car is started ice cold (oil is making it into the combustion chamber).

Jim

 

[Rodney87GN]

Bringing this post back from the dead...

Mine does the same thing. First start cold in the morning I get no smoke. If I shut it off for about 10 minutes after driving around I get the puff of smoke at startup. Oil is clean and I'm not losing any coolant so I think my head and intake gaskets should be ok (I hope).

I'm leaning towards leaking injectors too because fuel psi drops off to around 20 psi in 15 minutes or so. Otherwise car runs great with no smoke while idling or getting on it. It's kinda embarrasing on startup because it makes the car look like a POS, lol.

Dr Jeckel, did you figure out your problem?

 

[bsdlinux]

First start cold in the morning I get no smoke. If I shut it off for about 10 minutes after driving around I get the puff of smoke at startup.

Seals and or guides in the heads

 

[Rodney87GN]

I thought that too, but I always thought bad valve seals would puff smoke only when the car is started the first time after sitting for a long time. At least my old IROC with worn valve seals was that way.

I must have really bad valve guide seals if it puffs smoke after the it's been driven around for awhile. I really hope it's not the guides themselves that are toast.

Thanks for your input.

 

[Dr. Jeckel]

The car has long since been out of my possession. All I can say is that the turbo failed (had a boost spike of 30psi one night), the cam wiped a lobe....then a rod saw daylight.
Never really did figure out the puff.
I did figure out that, although very fun to drive, the gn/ttype's are plagued by problems caused by alot of horsepower and 80's technology. I do miss it though, mainly the sound of the turbo and the feeling as it spooled.
Good luck to ya.