Blue smoke

2009 4x4 Tacoma TRD with 185K on it 99% HWY driven no hard driving at all , oil changes about every 6K i have noticed a few times when starting a cold engine i see a puff of blue smoke come out of tail pipe any thoughts what it could be? or is it prelude to somthing ?

 

Blue smoke = oil in the combustion chamber. It is almost always worn rings, but it is possible (though very unlikely) your headgasket is leaking oil into the chamber but not coolant.

Try running the next weight oil up, aka a quality 10w40, high mileage oil. It won't solve the underlying issue but will help mitigate it.

 

Yes on oil in the cylinder, but at startup its usually due to leaking valve guides.

 

This has also been my experience. Usually only does it after sitting correct.

 

Valve seals and or valve guides. Really doesn't hurt anything unless it's real bad. My Camry with 156k is doing it now too.

 

Jimmyh yes after it has been sitting for a while . i will have the dealer go up to the next level of oil weight next time like i said only happens once in a while

 

thanks for the responds BTW

 

Heavier oil isn't helping anything. It's still going to get by the valve guides or seals, and tax an old oil pump. A nice valve job, or just put in new seals and guides. That's the fix for it.

 

This was a common problem on the old small block Chevy engines. Would still run like a scalded dog though.

 

Thank again Rock Lobster why do u think the PCV valve might be the Cause? Although I have not replaced it yet

 

The PCV valve is another possibility of oil smoke at start up.

 

I guess no one has said this but have you done a leakdown test yet? That should confirm if there's a issue or not instead of guessing here and there. Just a thought here.

 

A cylinder leakage test?

That tests for a blown head gakset, not oil making its way into the combustion chamber Lord Helmet.

 

No a compression test will show a blown head gasket. A leakdown test will show the conditions of the valve seals.

 

Well leakage of the piston rings, as well as the oil control rings. I typically don't bust that out unless I'm testing for blown head gaskets though.

 

A leakdown test is a more precise test of where the problem is where a compression is vague.

 

I think you have it backwards man. Lol

The compression test tests the integrity of the systems ability to hold a seal used mostly for checking for bent valves and their ability to hold compression of the pistons and the cylinder leakage test detects for any leakage within the cylinder, mainly piston rings and head gaskets.

Under the circumstances, I would probably do both anyways just to cover my avenues and make sure the engine is healthy and sealing correctly then work my way up the process of elimination.

 

I disagree. You do know when you do a compression test. you crank the motor right? You can't tell the condition of the valves seals when you do that. With a leakdown test you add constant air pressure and THAT is how you find where the issues of leaks is coming from. That is why a leakdown test is a more precise why of checking a engine internals.

 

Yes I know that's how you perform both tests. You crank, give it a few revolutions to build up pressure, then check the guages to see what kind of pressure you built up then look for large variances between the amount of cylinders the engine has. The other just as you described. Both have their place in auto diagnostics.

I think you may be using terminology I'm not used to hearing. Either way, I'd still do both if the PCV valve $5 check doesn't do it.

 

Well that's the terminology I was taught in mechanic school and before hand. It's pretty much a universal term in general. But a PCV valve replacement wouldn't hurt either but anything else I'd do a proper diagnostics before replacing parts just to replace parts.