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Transmission slips then fails; white smoke exhaust

R

rtwash89

New member
Hi guys,

Last week I had experienced what felt like the transmission slipping on my way home from work. I had to give it more gas to keep it up to speed. Finally made it home and couldn't make it up my driveway as the car wouldn't go into gear (any gear at all). Pushed it to the curb and shut it off for a few minutes, started it back up and was able to shift it and get it up the drive into the garage. Decided to take my chances and try to get it to my mechanic with my dad following me; about a mile down the road I got a thick white smoke coming out of my exhaust that was leaving residue on my dad's windshield behind me. I got it about 5 miles further when the transmission started slipping again; coasted into a parking lot and tried to let it sit again before trying to drive it with no luck (won't shift into gear again). Towed it to the shop, then couldn't get it to go into gear either.

Shop told me the transmission is toast, or rather that there was a part within it that was forcing transmission fluid out of the transmission and into my engine/exhaust system, and that it would be cheaper to replace the tranny with a used one ($900 tranny with 67K on it, $600 labor...$1500 total cost) than it would be to get into the transmission and replace the part (I suppose labor costs to rebuilt the transmission in the repair process). I believe the part is a transmission modulator valve (does that sound right)?

I guess what I'm asking for is your advice on the matter. If it is this modulator valve, in your experience, does labor to repair it really include disassembly of the tranny (the shop I brought it to doesn't do transmissions)? And if so, would you suggest just going with the $1500 deal of putting in the used (67K miles) tranny? I guess I'm trying to determine which process would be worth the trouble, and if their diagnosis of the problem sounds right (they've been wrong from time to time, unfortunately it's my cousin that owns the shop, along with 2 others in the area, so I go to him for family discounts).

Thanks in advance,

rtwash89
 


What you posted makes no sense. Trans fluid can not get into your car's exhaust. It can blow out the vent and burn off the outside of the exhaust.
 
That's what I was told. My dad and I thought it was coolant that was burning, but since I'm not exactly a guru when it comes to trannys, or engines for that matter, I believed him. The white smoke is definitely coming out of the exhaust though, and there was also a bit of smoke coming out of the engine compartment, from behind the engine itself.

I thought it was the intake that finally gave out that my mechanic told me wasn't an urgent fix (said coolant was leaking into my engine) that was causing the smoke, but they just told me is was tranny fluid. :th_wtf:
 
It's not both. Transmission fluid only has one possible way to get into your engine. That would be if the trans cooler in your radiator burst and since the trans has more pressure than the radiator, fluid would go in. From there the only way it could get burned would be a bad lower intake, head gasket or bad upper intake (if na)
 


Okay, so assuming the intake IS bad, would that have effect on the car shifting into gear? Or slipping while driving? I'm trying to decide if this is just one problem or multiple.
 
Okay, I got more information on it. I guess I was wrong about it coming out of the exhaust; it just looked like it was. Mechanic says the trans fluid is being pushed out of the transmission and is burning up on the outside of the exhaust system. Must have been a hell of a lot of fluid burning up to make that much smoke. Regardless, it appears to truly be the transmission then. Still weighing the options on repairs though. Would you suggest getting the used one swapped in? I have no idea what condition that one is in, just that it's got 67K on it. It's either that or stick with the one I have and get the part repaired, 143K on it...
 
If you have a 97 with the vacuum trans and it's like the old chevys if the vacuum modulator goes bad it can suck trans fluid into the motor but i don't think that is very likely.
 
It's an 01 GT (3.8L V6). Not sure if it's got the vacuum, but from the way my mechanic described it to me half an hour ago, it doesn't sound like it's being sucked into the motor now, just gushing out of the transmission and all over the outside of my exhaust system.
 


Going with replacing the transmission with the used one my mechanic suggested. Crossing my fingers that it's in decent condition...
 
Your current trans to blow fluid out the vent, likely has a bad channel plate gasket or worse. That's what typically causes the issue you are having though.
 
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