Gen II MTX engine problem

[Pure Stock]

I am having an issue of a puff of blue smoke being emitted from the exhaust "only" on initial start up. As in the car is sitting for 8 hrs. or more. After about 5 -10 seconds after initial start up the blue smoke stops. As far as I can tell under W.O.T. there is no trail of blue smoke behind the vehicle. In 3,000 miles oil is usually low about 1/2 quart. Any ideas?

edit: posted under wrong section, should be under help and maintenance.

 

[gmorrell]

What mileage? Probably valve stem seals. As the seals wear and harden with age, they allow some oil to run down the stems after shutdown/cooldown. The oil accumulates on the top of the valve mushrooms and burns off at startup. You can change out the seals, but it's a big job with this motor, as the cams and buckets need to come out, and you need some special tools to remove and install the seals. The amount of work is generally not considered worth the effort to cure a little blue puff at startup.

When it gets intolerable, yank the heads and do a full valve job: Grind the valves and seats, new guides, new seals, etc.

If they're old, they all do it.

 

[Pure Stock]

What mileage? Probably valve stem seals. As the seals wear and harden with age, they allow some oil to run down the stems after shutdown/cooldown. The oil accumulates on the top of the valve mushrooms and burns off at startup. You can change out the seals, but it's a big job with this motor, as the cams and buckets need to come out, and you need some special tools to remove and install the seals. The amount of work is generally not considered worth the effort to cure a little blue puff at startup.

When it gets intolerable, yank the heads and do a full valve job: Grind the valves and seats, new guides, new seals, etc.

If they're old, they all do it.

Engine has 78,*** miles. I have the engine out of the SHO at this point. I can rent the tools to do the job. Looks like a fair amount of work just to get to the issue. I want to hang on to the car for a good while. I see your point though.

 

[kikkinasphalt]

i agree if your going to take it apart.. might as well get everything done then

while its out, be sure to 60k it

 

[rubydist]

I agree that its almost certainly valve stem seals. Sometimes, you can add some seal conditioner that will soften them up enough to make it noticeably better, sometimes it doesn't help at all, but its only a few bucks to try it.

 

[Eric VerValin]

x2 on the stem seals. When I had my headwork done, they were all pretty cracked and old looking. Good time for a 3 angle valve job..