Smoke when letting off throttle?

[dan03mach]

Ok my car hasn't ever really ever had smoke coming out the exhaust but now it is. There is a little bit while idling and at WOT but when you let off of it after going WOT it smokes alot. What is causing this? What could cause this?

Thanks
Dan

 

[Tom's_03SVT]

scavenger pump...?

 

[dan03mach]

scavenger pump...?

No pump, top mount turbo and just a drain line. Also I put one of those water/oil seperators on the passenger side valve cover to catch oil coming out under boost. I put that on there about a month ago and the smoking issue started a couple of weeks after I put that on. Could I not be getting enough crank case ventilation now? I use to just have an open breather on both valve covers.

 

[blowngt]

Does it smoke at all on initial start up??

If it does, it's most likely bad valve stem seals.

If it only does it on decel, then it could be blow by.........

 

[yellow03vert]

When mine did this is was the seals on my turbo. It could also be valve seals like someone already mentioned.

 

[04SilverSerpent]

Blow-by imo....what kind of oil are you running? I was told to run regular valvoline since synthetic gets by the seals. From what the builder of my setup told me, most turbo cobra's smoke to some degree...just a matter of how much. My smokes abit on startup as well etc.

 

[dan03mach]

Blow-by imo....what kind of oil are you running? I was told to run regular valvoline since synthetic gets by the seals. From what the builder of my setup told me, most turbo cobra's smoke to some degree...just a matter of how much. My smokes abit on startup as well etc.

Well it didn't smoke at all for since I finished the build in march of 09 and now it is smoking. It smokes a little at idle and while running but not much at all. Most of the smoke comes from when I go WOT and let out of it. I use Ford Motorcraft oil. I'll look at my drain line and also check and make sure the crank is getting enough ventilation.

 

[blowngt]

Also, the next time you change your plugs take a look inside the chamber with a flashlight.

If it's wet with oil, it's either blow by or valve stem seals.

At least this way you can start the process of elimination.

I speak from expierence. I had both bad seals (lots of smoke at start up and during decel), and blow by (caused by crappy gapless rings we experimented with). The bad rings gave me a ton of smoke on decel. It was to the point of being embarassing......

 

[2bscrewed]

Could be turbo seals. Is there any oil in the intake tube?

 

[rotor_powerd]

My RX7 used to do this, then it started slowly smoking all the time except when it was in boost. The seals in the turbo were blown.

What size restrictor are you running?

 

[dan03mach]

Could be turbo seals. Is there any oil in the intake tube?

Nope... I think it is cause by not enough ventilation on the crank case. I took the oil seperators off yesterday and just opened up the valve cover vents to the atmospher and the smoke almost went away after running it for a while. Then I put the seperator back on and the smoke started to come back. So I think that is what it is. I'm going to do some more testing later on.

 

[dan03mach]

My RX7 used to do this, then it started slowly smoking all the time except when it was in boost. The seals in the turbo were blown.

What size restrictor are you running?

No restictors in the oil line. You shouldn't need any running turbonetics turbos. I know many people that run these turbos and none of them have restrictors in the oil line....

 

[Alb Cobra]

No restictors in the oil line. You shouldn't need any running turbonetics turbos. I know many people that run these turbos and none of them have restrictors in the oil line....

I don't have a turbonetics but I needed a restrictor on my GT42-76, was told by precision that the turbos like 20-25 psi and our oil pumps produce more than that on start up unless you use a restrictor.

It it is smoking a little at idle and then like a freight train after you get on it then it is a good chance the seals are going bad on your turbo...should only be 300$ to rebuild.

We made a drain canister just to see how much oil actually flowed under normal idle and it was suprising how much oil there was though the restrictor we used. Filled up a glad sandwhich container half way in less just a few seconds.

 

[dan03mach]

I don't have a turbonetics but I needed a restrictor on my GT42-76, was told by precision that the turbos like 20-25 psi and our oil pumps produce more than that on start up unless you use a restrictor.

It it is smoking a little at idle and then like a freight train after you get on it then it is a good chance the seals are going bad on your turbo...should only be 300$ to rebuild.

We made a drain canister just to see how much oil actually flowed under normal idle and it was suprising how much oil there was though the restrictor we used. Filled up a glad sandwhich container half way in less just a few seconds.

It really didn't smoke at all when getting on it, but when you lifted off the throttle, that is when it would smoke.

 

[04SilverSerpent]

Were you running breathers on both sides? Right now I have a breather on the pass side and i'm running a small catch can on the drivers side.

 

[2bscrewed]

No restictors in the oil line. You shouldn't need any running turbonetics turbos. I know many people that run these turbos and none of them have restrictors in the oil line....

I have turbonetics turbos, and I need restrictors. Without them, it smokes like a freight train.

 

[dan03mach]

I have turbonetics turbos, and I need restrictors. Without them, it smokes like a freight train.

Yeally? that is weird. All the turbonetics turbos that I have seen put on with hellion kits at one of the shops I go up too all the time don't ever use oil restrictors and none of them smoke. Mine never smoked untill I put that oil seperator on which cause too much back pressure in the crank case. I'm running a -4 line too. BTW what type of turbo kit do you have and were are your turbo(s) mounted at?

 

[dan03mach]

Were you running breathers on both sides? Right now I have a breather on the pass side and i'm running a small catch can on the drivers side.

When it didn't smoke yes I was running breathers on both sides, but now that it is smoking I have a breather on the driver side and then just an oil seperator on the passenger side that vents out to catch the oil under boost. That is all I wanted was something to catch the oil under boost. I got tired of wiping off my valve covers from the little bit of oil that would get pushed out under boost.

 

[KooK]

If you have a journal bearing turbo, DO NOT use restrictors or you will destroy the turbo. If you have a ball bearing turbo, call up the manufacturer and see what they recommend, normally a .040 is fine. Last time my car was smoking like this (fine at wot and horrible as soon as I let off) it was the oil seals on the turbo. First thing is first, remove the intake pipe going into the turbo and wiggle it to see if there's play, if not then remove the turbo itself. If there's oil in the manifold/header then it's coming from the engine. If it's dry in there and wet in the downpipe it's coming from the turbo and needs new seals (probably a rebuild). When this happened to me, it seemed like it just happened all at once with no warning.

 

[Eatonualive281]

I have turbonetics turbos, and I need restrictors. Without them, it smokes like a freight train.

does it really?? i have that same problem, it smoked in boost and right after i let off...was it the same for you?