friend told me that when i romped on my car he supposivly saw some blue smoke!

could this be my piston rings?

also my car has about 112k miles and my coolant sensor went out, and i think my low oil is comming to an end. I checked the oil level and it seems fine.

im most likely going to run sea foam in it!

Randy

 

Blue smoke is always oil...so its coming from somewhere...either your rings or your valve seals...if its at WOT its probably the rings

 

Take a well worn dollar bill or other piece of flimsy paper and hold it up to your tailpipe while the car is running.

You want to hold just one end, and you place it so that if the car were not running and blowing the paper away, it would completely cover the opening.

If the exhaust pressure keeps blowing the paper away, your rings are fine.

If the paper gets sucked into the tailpipe (hold tight so you don't lose it.), then your rings are probably shot.

If you have true duals, do it on both sides to find out if it's limited to one bank.


And before you ask...?
No, I really don't know why it works.

 

Be sure of the colour of the "smoke":

Blue = oil

Black = fuel (too rich)

White = coolant

(Very simplified guideline = not necessarily always right!)

 

Can't a bad PCV valve also be a culprit for blue smoke @ WOT?

 

No it wouldnt!

 

Wow, as obvious as that sounds I've never thought about it. That would make great sense to me, not thinking about it further. Phantom you disagree?

 

Well, the PCV valve allows the crankcase to vent itself into the intake tract so that crankcase gasses wont vent to the atmosphere.

If one were malfunctioning in a way that wouldn't let the crankcase vent it's excess pressure then pressure could build up and make it more likely that the gasses would try to find an alternate route out.

However, there are STILL only a few ways that crankcase gasses can get into the combustion chamber and thus out the exhaust.

They could in theory find their way through a small crack in the intake gasket, but that would probably cause rough running anyway; which you would notice. Plus it's not real likely for other reasons.

The two LIKELY ways that the excess pressure could find it's way into the chamber are; past the valve stems and past the piston.

Frankly, leaky valve stem seals would lead to a lot more oil and smoke, plus fouled plugs. Or at least, that would be the general tendency, because they would let a generous amount of liquid oil into the chamber. You'd also be likely to have smoke all the time, not just under hard acceleration.

Rings though... that would tend to allow VAPOR inside the chamber, as opposed to liquid oil. You would tend not to foul plugs and it would tend to leak less at part throttle.

So, while a bad PCV valve can be exacerbate the problem, you would still need either bad rings or bad stem seals to allow the problem to manifest.

 

If the smoke appears when you hit the gas while its running, its the valves.

If the smoke appears throughout the rpm range, its the rings.

 

yeah that makes a lot of sense. not sure if this is exactly what you were saying, but the way i see it, not enough oil would ever creep back through the valve and into the intake to actually make blue smoke unless you had a bigger problem.

 

Thats just a little technique I picked up through stock car racing. Its never failed.

 

dollar bill was being blown out and not sucked in....

maybe he was tripping because i do use alot of nitrous and when i spray **** comes out most of the time!


Randy

 

Blue(ish) smoke = Oil

 

Then it's probably not your rings.

 

that dollar bill trick is for cheeking exhaust valves
if the exhaust valve sticks open during intake stroke it sucks in and that creates a small vacumme in the exhaust and that would pull the dollar inward