90 Loyale 3SPD A/T losing ATF by the quart. No sign of leakage from the the pan, but I changed the filter, gasket and fluid anyway. Still losing a quart about every 50 miles, but thankfully the tranny shifts fine. After filter and atf change, there was billowing white smoke from the exhaust for the first 5-6 miles. Now it's just mild smoke.

 

Presume this is a hole in the vacuum modulator diaphragm allowing atf to be sucked into the intake manifold and burned in the cylinders. Could any voices of experience confirm this, and also perhaps tell me if a vacuum modulator from an '87 would be the same part as the '90 [got one in the boneyard ...]? And, does that modulator unscrew readily from the tranny housing - or is it a crap-shoot getting out intact? Thanks.

It sure sounds like a failed vacuum modulator to me. I can't answer whether the later unit will fit (I kind of doubt it) or how difficult the 3AT's is to change. I will say that oil is a lot lower octane than gasoline, and you can do permanent damage to one or more pistons if you run it hard in this condition.

It just unscrews (lefty-loosey), You might need to put channel locks on it to get it moving at first. It's holding back whatever ATF is still in there, so make sure you're quick about it or have a catch pan under it. I'm not sure if the 90 part will fit, but I don't see why not. If it doesn't, the Fram replacement is around $15.

Originally posted by asavage

I can't answer whether the later unit will fit (I kind of doubt it)

 

Whoops! I read that as you were trying to use a '96 modulator, and I didn't think that that would work. Sure, I think a modulator from a '90 would likely work.