Background
---------- This is a summary of the threads:
Re: Changed engine, heated ventilation smells oily
Worn valve seals were suspected. They were replaced on a 2nd visit, leak-down test didn't indicate any problems, pressure test of the coolant system did not reveal wet spots in the heating core (according to a tech, the core was not removed). Engine was "flushed" and a teradyne was performed.
Currently
--------- For the past week (since the valve seal replacement), the caustic chemical smell persists at noticable levels, and the burning smell is gone. Instead, there is a hot oil smell; I suspect that this is what the chemical smell turns into when the engine has warms up. A sure sign of prolonged exposure is continued coughing for upto a day after the exposure. The shop techs hardly notice the smell, if at all, though friends do; this is not surprising, considering the strong smells in the shop. Friends are only exposed to it for short durations, and only some are bothered by it.
Keeping all windows open while driving only reduces the problem; the hot oil smell is noticable outside the car, comes in through the windows. It is more noticable when travelling at low speeds (1st/2nd gear), and especially right after a duration of high revs e.g. shifting from 1st 2nd (maybe during a left turn), downshifting into
2nd, or just when the lights are against you during crowded city driving.There doesn't seem to be any fresh fluid spots on the ground where I park. This observation is slightly complicated by the fact that there is melting snow, and large spot is due to the leak from the original engine.
Oil still seems to be burning at approximately the same rate as before. The symptoms don't match that of a head gasket problem. There is still white smoke during startup, while the smoke appears invisible after engine warms up. I'm not sure how to distinguish between water vapour and coolant in the exhaust.
In addition to a possible external oil leak onto a hot part of the exhaust system, JeB suggested that the crankcase vent might be dumping into the engine compartment. I was googling and asking people about this, and found that the high crankcase pressure that results from a plugged PCV valve can also cause oil to leak out from any seam. I was hoping that more experienced NG participants can answer some questions I have about this line of thinking.
- Venting into the engine compartment, and associated oil leaks, would manifest during engine operation, especially high revs. Is this a good possible explanation for why the fumes seem more noticable at low speeds and right after high revs?
- Wouldn't this cause outward signs of an oil leak e.g oil stains on the engine components? None were seen. Would the heat of the engine exterior cause them to evaporate?
- How likely is a plugged PCV valve when I don't see the following symptoms?
- Rich fuel (black exhaust) due to lack of dilution by crankcase vapours
- Rough idling due to upset fuel/air mixture
- A person I talked to said it wouldn't be too surprising that fumes get into the passenger compartment from the engine compartment even when the fan is set to recirculate, since the barrier is anything but a perfect seal. However, my mechanic mentioned that he checked all the seals between the engine compartment and any airway that might lead to the passenger compartment. To what degree is each person correct?
- Though I still trust my mechanic, I'm considering bringing this to somewhere else to get a fresh perspective. I don't think I can continue using myself as a guineau pig in trying find clues about what conditions are linked with the fumes. Any opinions on this? Up til now, I can dress warmly and roll all windows down, but it will soon be raining/slushing/snowing, and I need to blow hot air against the windshield.
Thanks for any thoughts on these.
Tercel Owner