Black Smoke Blue Smoke
 

So I know black smoke is fuel and blue is oil. I've got black smoke under hard acceleration but I've never noticed blue smoke out of it before just recently. After I had done some work on it it was idling for several minutes in the street before I was able to drive it back into the garage. I was checking the accelerator linkages and revved it hard from the engine bay. I noticed a significant puff of blue smoke the first time I revved it after it was idling for a few minutes. Didn't do it the following few revs that I gave it. I know it's oil. My question is why only on first rev after a long period of idle? Is it valve seals? I would assume if were rings it would show blue smoke constantly no?

- Peter.

Probably the valve seals, yes. From what I understand if it's blowing blue after sitting for a while it's the valve seals.

Every old-ish diesel I've ever seen does that, even our 10 year old work truck.

Only start worrying about it when it becomes like my car....10 minutes of idling then flooring it = white smoke screen :P

Sort of what I figured. Thanks.

- Peter.

Valve Stem Seals are cheap. The job is not too bad but kind of slow.

Make sure Pistons are at TDC so the Valve does not drop into the Engine.

Thanks for the tip. It'll be a while yet before I get around to trying my hand at doing this one.

- Peter.