Keith_M
Jedi Knight
Offline
I had a previous thread about white smoke from my 1275 engine, and I'm happy to say that the white smoke is gone. The head was not flat (the machine shop said .012 had to be taken off to get it flat), and after re-installing the head, the copious amounts of white smoke are gone, but now I have much lesser amounts of blue-gray smoke. I think the blue-gray smoke was always there, but was masked by the white smoke.
The blue-gray smoke only occurs as the car is warming up, and only when you open the throttle. It goes away completely when the engine is completely warm. I'm pretty sure it's oil coming through the PCV valve because there's oil in the PCV, and opening the throttle should reduce the vacuum and open the PCV valve, allowing high flow rates. I've checked the operation of the PCV valve (it's one of those flat-topped affairs that empties directly into the intake manifold) and it seems OK to me; the diaphragm is intact and flexible and I can close the valve by sucking on the bottom of the unit.
My question is: Why is this occurring and can I do anything to stop it? I have read that excessive blow-by can cause high flow rates through the PCV valve, and I suspect this may be my problem. The engine runs fine and doesn't smoke at all when warm, so I'm resisting a ring job.
The blue-gray smoke only occurs as the car is warming up, and only when you open the throttle. It goes away completely when the engine is completely warm. I'm pretty sure it's oil coming through the PCV valve because there's oil in the PCV, and opening the throttle should reduce the vacuum and open the PCV valve, allowing high flow rates. I've checked the operation of the PCV valve (it's one of those flat-topped affairs that empties directly into the intake manifold) and it seems OK to me; the diaphragm is intact and flexible and I can close the valve by sucking on the bottom of the unit.
My question is: Why is this occurring and can I do anything to stop it? I have read that excessive blow-by can cause high flow rates through the PCV valve, and I suspect this may be my problem. The engine runs fine and doesn't smoke at all when warm, so I'm resisting a ring job.