Hi Gang,
Something new has started on my '87 TII S4. When coming off the mountain passes here in Colorado, I occasionally get huge clouds of blue oil smoke out the exhaust.
It seems that it happens when I gear down to save on brakes while on the downside of a 10,000 ft hill. If I depress the clutch and go to brakes to control speed, the smoke quits.
Any ideas where this is coming from?

THX

- k -

 

Rev your car to 5k rpm and keep it there for a while. Blue smoke pouring out?

 

No smoke when revving. just when i downshift on a really high/long hill. Soon as I hold the clutch in, the smoke quits. It may or may not start smoking again if I release the clutch and begin coasting against the engine again. Sometimes it does, other times not.

- k -

 

No Ideas, gang?....

 

So it only happens when the engine is pulling a lot of vacuum. Do you have a lot of blow by from the oil filler spout(air) when you rev? It sounds like maybe one of your oil seals has a crack in it and the oil gets a little help through when the engine has the throttle closed at high RPM.

As a CDL driver, and I used to live in Breckenridge, IMO you shouldn't need to use engine braking to save your brakes on your car. Trucks have jake brakes to plug the exhaust and give huge amounts of engine braking, your just using engine compression which does some but not enough to matter on a car. I'd use it as a last resort, sure, but clutch wear is more expensive than brake pads.

If it onlysmokes right now when you engine brake, I guess, don't do that