intermittant blue smoke

[bandaidmd]

Hello All,I did a forum search with no luck so heres my ?
02 linc ls 3.9 v8 155k miles
This car has progressed from once in a while at startup belching a clould of blue smoke to doing it 80% of the time(at cold startup). It will also at random times let out a cloud at highway speed accompanied by noise from the engine which sounds like it my be spark knock.
My fist thoughts were the valve seals were starting to go bad but when it decides to belch its like a battleship laying down a smoke screen as if the oil was pooled up someplace and dumped into the intake airstream, my only experience with valve stem seals was little bits of smoke at startup and after letting off and getting back on the throttle and i have tried to let off the gas (high vacuum) and re accelerating but i cant make it belch. If you drive at hiway speeds "sometimes" when you accelerate to pass it will make the sound and belch out the cloud. The intermittant part it is what has me thinking theres something else going on here.

 

[joegr]

Maybe the oil returns on one bank are clogged and sometimes way too much oil is pooling in one of the valve covers and being sucked in by the PCV system?

 

[bandaidmd]

Maybe the oil returns on one bank are clogged and sometimes way too much oil is pooling in one of the valve covers and being sucked in by the PCV system?

glad you brought that up i was thinking a cloged return but wouldn't have thought that much could get by the valve guides at one time..didnt think of the pcv system.

 

[G-RELL]

I'm not sure a pcv would cause a spark knock though....

 

[joegr]

I'm not sure a pcv would cause a spark knock though....

Pulling a lot of oil into a cylinder will increase its compression. Of course, we don't really know if the OP is hearing spark knock, or some other noise.

 

[oddball]

If it's sucking in that much oil, it won't sound good.

 

[bandaidmd]

The noise is defiantly detonation caused by the oil dumping into the intake air stream,where can it be pooling up like that or why is my 64 dollar question.

 

[bandaidmd]

Valve covers are coming off and also doing a compression check sometime this coming week.

 

[02blackls]

Did you figure anything out with this, I have a very similar problem and am not sure what it is, but could use some help. It is kind of embarrassing to leave the cloud that it does.

Thanks

 

[centason]

It maybe blow by at the rings. What's the history of the car?

 

[joegr]

It maybe blow by at the rings. What's the history of the car?

Easy test for excess blow-by:

With the engine running, remove the oil fill cap. Place your hand over the mouth of the fill opening. If you feel very slight suction, you're good. If you feel puffs of air, you have excess blow-by.

Note however that excess blow-by is not required in order to have excess oil consumption from worn rings and/or cylinder walls.

The OP indicates that his problem is intermittent, which tends to point away from it being a worn ring issue.

 

[bandaidmd]

pulled plugs and did a compression test, 7 avg 210 one was a bit low @195 but its not that far off the avg. Plugs were not oily and show no carbon type buildup. Full disclosure;i paid someone else to do this work and he found the air cleaner extremely dirty(oops guess i overlooked it) . Changed oil and added a bottle of lucas ,will update again when i have some drive time.

 

[hotrod03lincolnlsV8]

I have seen a small puff of smoke when i start my 03 w/108k on rare occasion. I found it happens when the car is started cold and run for less than 5 min and shutdown. (usually moving the car around the driveway) The next start has the oil smoke and once, spark knock.

When the oil is cold and thick it will not drain down as well as when the engine/oil is hot. I suspect the returns might be restricted and/or there are a couple of intake valve seals that are not sealing as well as they used to. Total oil consumption (in 3k-4k mi) is not measurable so at this point i dont know that i will worry about it.