Smoking Exhaust on tickover.

Question if i let my car idle, after 6 minutes exact its starts to smoke. On start up nothing at all and general running nothing at all. My car does not seem to use oil or make oil and coolant level stay constant.
The fumes are a mixture of oil and fuel mixture.
Any ideas? Was contemplating a compression test, then a check of the valve stem guides but i would have expected these faults to show on start up.

Could be turbo. As it warms up and expands, oil begins to leak through the seals, and thus smokey exhaust..?

almost definitely turbo

had something very similar on a GTA a few years back and it was the turbo.Didn't always smoke underload but if you left it idling when hot after a few minutes it used to seep oil into the exhaust system - enough to make it appear the car was on fire!

Thats right, normally, if its the turbo, it won't smoke on boost, as the bearings are held under load, its only when the load is reduced you then get leakage past the seals.

Having just removed my Turbo, not a job for the faint hearted. It now appears that the problem may not be the turbo after all. To that end if anyone has the same or similar symptons as mine don't jump at the turbo.
Check The brake master cylinder first. (':oops:')

..it won't be the brake master cylinder...

Check The brake master cylinder first. (':oops:')

Why? Please share your learning experience with us.

You do not need loads of oil for it to smoke..
If your master cylinder is leaking brake fluid in to the vacuum chamber this could in theory be sucked in to the intake manifold and burned. This would show itself more under idle as this is when the vacuum is at its greatest.
Possible.
I’m not saying this is my fault but it would have been sensible to check first.
All you would have to do is disconnect the vacuum pipe, obviously block of the inlet manifold hole and allow the car to idle. If it smokes Turbo if not fault found master Cylinder.

You do not need loads of oil for it to smoke..
If your master cylinder is leaking brake fluid in to the vacuum chamber this could in theory be sucked in to the intake manifold and burned. .

Yes, on a front engined car where the master is above the engine

On a GTA it would have to pull it over 3 metres and up a gradient.

Also, if it was brake fluid, it would do it straight away from cold, which you said it didnt in the first post, and that it smelt of oil/petrol...

maybe the brake master cylinder and vacuum line are full of fluid???
easy to check by just disconnecting the vacuum line at each end i guess.

as it only smokes after 6 minutes on idle, could it be a sensor that is confusing the ECU to do something out of the ordinary, maybe???

maybe the brake master cylinder and vacuum line are full of fluid???
easy to check by just disconnecting the vacuum line at each end i guess.

Could be, but I doubt you'd have any brakes too...

If it was that full, it would be idling badly too..

as it only smokes after 6 minutes on idle, could it be a sensor that is confusing the ECU to do something out of the ordinary, maybe???

The only sensor that could cause anything from the exhaust, would be the coolant temp sensor, which would cause it to run rich, but no more rich than when the car is first started.

[stephendell]

Are talking black,white or blue smoke?

I had a perished vacuum pipe to the map sensor. When it started to crack I got black smoke. Replaced the pipe and problem disappeared.