Hey all,

I’ve been looking at this forum for a while, so I figured I should make an account so that I can post my car’s problems and see what everyone thinks.

I’m the owner of a 1978 Oldsmobile Toronado, bone stock. And for the last couple months, I’ve had problems with my transmission oil.

Whenever I add transmission oil, it seems to completely disappear out of the pan by the next few days depending on how much I drive, but generally, I added a quart just about every other day.

I told my dad that this was happening, and he said there must be a leak, hence, me pumping this thing with endless amounts of oil. But I had my superstitions and I told him that I thought the oil was getting into the engine block somehow. This is because as my transmission oil was decreasing in amounts, my motor oil levels were rising.

Now I’m in the process of rebuilding the transmission, and I’m totally stumped as to how transmission oil can be mixing with motor oil. Can anyone tell me if there are any parts on this transmission that connect the two types of oil in any way? Or if broken, have the potential to? The transmission is in a million pieces right now, just ordered a new vacuum modulator that was faulty, and seems to have been pumping oil into the heads. So that’s half of my problem, but I figured that unless I have worn piston rings or something of the sort it shouldn’t be combining with the motor oil.

Thanks,
Luke

 

The transmission and engine crankcase are not connected. You may have a leaky vacuum modulator on the transmission though. Check by removing the vacuum modulator vacuum hose. If it has ATF in it you know the vacuum modulator is bad. The leaking ATF would go into the engine, but it would be burnt.

If your oil level is rising I'd check your fuel pump. It may have blown a diaphragm and is pumping fuel into the crankcase.