3.5 Ecoboost Smoke, Start up
Hello to all,
After setting this vehicle will smoke upon start pretty decently for approx 10-20 seconds. There is oil residue on the fresh air pipe going to the left turbo, we pulled the Pre cat O2s, the Left had lots of black oil soot on it , the other is clean. oi level is ok. When we started it with the Pre O2s out, there was smoke from the left and NOT the right…
We are trying to differentiate between the PCV system failing , the turbo leaking oil, the engine burning it…
We did a compression test on all cylinders, 1= 106, 2 = 107, 3= 110, 4= 106, 5= 111, 6 = 122 psi…..
My first thought was turbo is at fault, removed the pipes, the shaft has very minimal play both ways…..
Just trying to do whats needful and not more…. any of your thoughts will be appreciated….
I had an online class semi recently about turbos (CTI maybe? Tanner was his name I think. He is on this forum)) Where I learned that the pressures should be equal on the pressurized side of the intake and the exhaust manifold before the turbo. Because there are no actual seals aside from the tight clearance between the turbine shaft and bushings, any pressure difference between the exhaust and…
What kind of smoke? Head gasket or fuel white smoke, fuel injector leaking black smoke or blue smoke? Let’s get the detail of the smokes! Lol.
In the original post he said “There is oil residue on the fresh air pipe going to the left turbo, we pulled the Pre cat O2s, the Left had lots of black oil soot on it , the other is clean. oi level is ok.” I assume it is oil smoke he is seeing.
Sounds like a blown or stuck injector on the left bank. I also suggest doing a cam and crank correlation, because these are bad about timing component issues. They are snappy little engines so people tend to romp on them, this increases the wear and tear issues.
I don't like the 16 psi higher on #6 cylinder. Are you getting excessive crankcase pressure? The smoke on startup is every time? Or do you need to drive it under load to get it to smoke again on startup. Probably worth it to put a Pressure transducer on the crankcase and see if you are getting excess blowby pushing oil into the breather system.
Hi Mervin, In the “old days” this was an early warning sign of bad valve guide seals. Cylinder #6 would be suspect to me. Let the engine sit over night and then pull the plugs to inspect the cylinders with a bore scope camera. You may likely find a small amount of oil resting on a couple of the pistons. Being that is only one bank, focus on that bank. Does it have dual PCV's? Here is a TSB…