New engine, old turbo, smoke when idle
Turbo Mini Forums

Hi,

I've been reading a few topics here about blue smoke, and what it can be. I have a newly build engine, the only things not new are the valves, the turbo, and the carb. Its overbored with new pistons and all that jazz.

For now I have found that it could be the turbo inlet side, where I should see oil in the plenum.
It could be the turbo exhaust side, where I should not see oil in the plenum, and no oil in the cylinders.
And it could be the valves, where I should see oil in the cylinders, and not in the plenum.

I need to add to this, that between the engine build and running it for the first time, it stood still without oil (except for the building oil) for over a year due to time issues.

Can you guys suggest any more tests I can do to determine where this problem is? I'd prefer to solve this in car, I don't want to take the engine apart

Cheers, Roger

Check the things you have mentioned first.

If something is worth doing, it's worth doing half of.

oil leaking into the cylinder can produce blue smoke out the tailpipe.


what could be happening is your motor oil is leaking past your piston rings and getting into the engine cylinder and mixing with your fuel and ultimately burning along with the gas, but i could be wrong.

i would look to the head first.

You can remove one possibility by disconnecting the turbo compressor from the plenum and drive it. It will be SLOOOOOW but you can rule out turbo compressor side oil contamination based on smoke or the lack of it.

Can't you overspeed the turbo doing this?

If something is worth doing, it's worth doing half of.

Yes, but I've done it for a quick test before. It's not like it will be doing any hard driving. It would be best not to drive flat out anywhere... just tootle around for a few hundred yards and look out the back for smoke...

Just take the pipe off and look if you suspect compressor side oil contamination, or am I missing something?

Yes i moved to the darkside

Instagram @jdm_brett

If the engine has been just rebuilt then can I offer the advice I was given - get out there and give it some welly to get those rings bedded in.

Did it work? I seem to remember tom saying "Run the fucker in" or words to that effect.

Like a dream.