Topic: Puff of smoke

[neale_rs]

My YJ once in a while starts up with a puff of smoke out the exhaust.  This is about once every 5 times it is started.  After starting it runs fine with no smoke and doesn't consume any oil that I have been able to detect. I used to park it on level ground and it never did this.  Now, after moving to another house, I park it facing uphill.  I think this may something to do with it.  I've heard this is related to valves.  Is this something I could fix easily just from above?

Thanks

[Jeffy]

My YJ once in a while starts up with a puff of smoke out the exhaust.  This is about once every 5 times it is started.  After starting it runs fine with no smoke and doesn't consume any oil that I have been able to detect. I used to park it on level ground and it never did this.  Now, after moving to another house, I park it facing uphill.  I think this may something to do with it.  I've heard this is related to valves.  Is this something I could fix easily just from above?

Thanks

Can you tell what color smoke it is?  Could be condensation in the exhaust that's vaporizing once you start up.  Also once the engine starts the lifters need a little time to pressurize.  Does it smoke if you romp on the throttle?  How about under a load like when climbing a hill?

Unless it's doing it all the time or you can recreate at the moments notice, then I don't think there is anything out of the ordinary.  I'd just keep an eye on it.

[aw12345]

If it smells like oil burning is kinda bluish white its oil however this is fairly common on high milage engines and they can run with it for a very long time. Provided its oil burning its just some oil that seeps past the intake valve stems
If it really bothers you, you can try and replace the intake valve stem seals. To me its more trouble than its worth

[neale_rs]

It does smell like oil smoke but it only does it on startup (and only once in a while), never when stomping on the gas nor at any other time.    From your comments it seems it is not something to worry about too much.  I'll try parking it facing downhill to see if that helps and keep an eye on it otherwise.  Thanks!

[jfrabat]

If it does it ONLY on start up, it can be that the gap between the valves and the valve guides is out of whack, and when it sits (engine off), oil trickles down to the valve, giving you the puff of smoke when you turn on.  I know this sometimes happens with aluminum heads, but not sure if it happens on Jeeps as well (although I would imagine it does). 

You can check of the gap, but you need to take the heads off the engine to do it (specs on the gap should be available in the chilton manual).

Felipe

[neale_rs]

Thanks.  It sounds like to much trouble.  I think parking it facing downhill will do the trick for now.