AOS or something worse?

[piper6909]

Hi. My 2002 2.7 blows a little blue smoke at startup. I blows water vapor as well, but I'm pretty sure there's some blue smoke there.

Is it time to change the AOS? It has 90k miles and I don't know the maintenance history. Or could it be something more serious?

Thanks!

[kk2002s]

A little smoke at start up can be normal, especially if the cars been sitting. A very basic test for your AOS is while the car is running, remove the oil fill cap. If it's very hard to get off due to vacuum draw, then that could be an indication it's on it way out. There should be some vacuum draw but not excessive.

[piper6909]

Originally Posted by kk2002s

A little smoke at start up can be normal, especially if the cars been sitting. A very basic test for your AOS is while the car is running, remove the oil fill cap. If it's very hard to get off due to vacuum draw, then that could be an indication it's on it way out. There should be some vacuum draw but not excessive.

Thank you, kk2002s.