getting some smoke after wot

[Wi Stang]

Hi Guys, I'm getting a little smoke out out of my car after I get on it. If I am just driving around town, or even accelerating at a little over half throttle, I don't see anything. But if I go wot to higher up in the rpm range I see some smoke in the rearview after I let off of the gas. I doesn't smoke while I am at WOT, just when I am decelerating immediately after. It only happens for a few seconds afterwards, and smells like oil smoke. I just was at the dyno last week and had my a/f ratio dialed in to just a little under 12 to 1 at WOT. I pulled a spark plug, and it looks pretty good too. The only thing I have changed since then is the timing on the BTM.
Any suggestions as to what might be causing it?

 

[CManT1914]

What color is the smoke?

 

[Wi Stang]

It is a greyish color. It's not white, but it isn't dark either. (kind of a bad explanation) I always have the windows down, and it smells a lot like burning oil.

 

[94-302-vert]

bluish or steamish? Any black build-up on the back bumper by any chance?

 

[CManT1914]

It is a greyish color. It's not white, but it isn't dark either. (kind of a bad explanation) I always have the windows down, and it smells a lot like burning oil.

Well if it's not white, then it's probably not steam, meaning no burning coolant, which reduces the chances of a blown HG. I think you'd see more problems than smoke with a blown HG too.

If it's burning oil, it will have a blue tint to it, which can be caused by blowby or a blown HG.

 

[94-302-vert]

I had an 88 dakota taht blew the HGs... Bluish stinky smoke due to antifreeze....

 

[CManT1914]

I had an 88 dakota taht blew the HGs... Bluish stinky smoke due to antifreeze....

Your antifreeze burned blue?

 

[Wi Stang]

There is no black build up on the back bumper. I'll have to pay a little more attention to the tint of the smoke. thinking back it could have a bit of a blue tint to it. I just think it is weird that it doesn't do it while I am on the gas. Only after I let off.

 

[donjohn]

crap, i get the same smoke thing, i didn't think it was that bad of a thing... i only get it at WOT from a stop or slow speed

 

[95opal]

possibly unburt gasolina if its only happening when you hammer it

 

[Rootus]

Blue smoke on deceleration after WOT is probably PCV related.

 

[Wi Stang]

I'll check on my PCV valve tonight. I have an oil seperator on the PCV line, and inially there was some oil that it caught, but since then I haven't seen any more. Maybe it is messed up.

 

[194stang]

It could be the valve seals too. When you let off it creates a high vacuum condition, it could be sucking a little oil through the valve guide.

 

[Wi Stang]

I put brand new Trick flow heads on about 500 miles ago. Have many people had issues with the valve seals on new heads?

 

[94-302-vert]

Is there any oil in your antifreeze?

 

[Wi Stang]

The anti freeze looks good, and the oil looks good too.
How could you tell if the PCV valve is bad. I looked at it last night, and it seemed to work. I could blow through it pretty freely.

 

[Rootus]

The anti freeze looks good, and the oil looks good too.
How could you tell if the PCV valve is bad. I looked at it last night, and it seemed to work. I could blow through it pretty freely.

With any good aftermarket combo, it seems that the PCV is permanently screwed. Most people end up with a fair amount of oil entering the intake from the PCV unless they go through the trouble to install a catch-can in the line.

A friend of mine had pretty serious smoke on deceleration with his Camaro, turned out to be a faulty head (can't remember, might have been a crack, it's been too long to remember exactly what it was). You're experiencing a lot of vaccum on decel, which is why I suspect PCV first. Just how much smoke are you seeing?

 

[Wi Stang]

It will smoke for a couple of seconds on deceleration. It is enough to see a cloud on deceleration, but it isn't really thick smoke.
I'll pick up a new pcv valve today just to eliminate that as being an issue.

 

[MLC Stang]

Wi Stang,

As mentioned before, backing off the throttle after a WOT run creates a very high vacuum condition in the combustion chambers. If there is any possibility of sucking oil or oil fumes into the cylinders this is when it’s going to happen.

It could be coming past the valve guide seals or past the piston rings. Do you have to add oil to the crankcase between oil changes? i.e. is the engine consuming oil? If so, how much.

Have you done a compression test lately? That would tell you about the general condition of your rings and seals.

 

[Wi Stang]

Since putting all the new engine parts on, I only have about 500 miles on it. The oil level is a little lower than it was initially, but I will need to get more miles on it before I can say how much oil it is consuming.

My dad has a compression tester. This weekend I'll head out there and check where all the cylinders are at.

Thanks a lot for all the help so far guys.