trans fluid loss

I have a 1994 Pontiac Grand Am which is mostly driven by my kids. A few weeks ago my daughter mentioned a possible transmission problem and I made fun of her over that -- what does she know about transmissions .... I only drive the car occasionally, and for short trips, and I had noticed some hesitation when accelerating from a standstill, which seemed to go away when the car warmed up. Yesterday I drove the car for 30-40 miles, and the transmission started slipping. I checked the fluid -- nothing on the dipstick. It took about

3 quarts to bring it up to the required level! I haven't noticed any trans fluid leaks, I I remember checking it a couple of months ago -- it was at the top mark back then. I did some reading last night and found a few references, including in this group, to a faulty modulator valve that can cause this problem. I'm planning to watch it for a week or two, and see if the fluid loss continues. My questions:
  1. Am I on the right track?
  2. Is replacing a modulator valve something I can do at home (I'm comfortable with wrenches), or should I take it to a professional mechanic? Thanks. Svilen
Reply to
Svilen Stoicheff
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Grand AM 1994 should have a 4T40E. There is NO vac modulator. Check and or Replace the side pan gasket, lower pan gasket, and filter. Check the TC seal. You can replace the lower pan gasket and filter at home.

Reply to
=?x-user-defined?Q?=AB?= Paul

Interesting. AutoZone sells one for $16.99.

Thanks, but I don't think it's possible for 3 quarts of ATF to escape through leaking gaskets without anyone noticing. Unless it somehow evaporates.

Reply to
Svilen Stoicheff

They may be correct. If your car has a 4T60(e), then it does have a vac.=

modulator. That's a lot of ATF being burned by the catcon.

Reply to
=?x-user-defined?Q?=AB?= Paul

"" wrote: > I have a 1994 Pontiac Grand Am which is mostly driven by my > kids. A few > weeks ago my daughter mentioned a possible transmission > problem and I > made fun of her over that -- what does she know about > transmissions .... > I only drive the car occasionally, and for short trips, and I > had > noticed some hesitation when accelerating from a standstill, > which > seemed to go away when the car warmed up. > Yesterday I drove the car for 30-40 miles, and the > transmission started > slipping. I checked the fluid -- nothing on the dipstick. It > took about > 3 quarts to bring it up to the required level! > I haven't noticed any trans fluid leaks, I I remember checking > it a > couple of months ago -- it was at the top mark back then. I > did some > reading last night and found a few references, including in > this group, > to a faulty modulator valve that can cause this problem. I'm > planning to > watch it for a week or two, and see if the fluid loss > continues. > My questions: > 1. Am I on the right track? > 2. Is replacing a modulator valve something I can do at home > (I'm > comfortable with wrenches), or should I take it to a > professional mechanic? > Thanks. > Svilen

Easy way of telling it?s the modulator is to pull the vacuum line off of it at the intake and see if it is wett with fluid.All the ones I have ever seen that leaked like that made the car smoke out the tailpipe because the vacuum at the intake sucks it through the motor into the cylinders and burns putting out a cloud of whiteish smoke.

Check the vacuum line first.

Reply to
Shakes73

Checked the vac line to the modulator -- seems dry. A Pontiac dealer is telling me transmission fluid leaks into the radiator. They want to replace the radiator and do all the related fluid changes and flushes. I am unconvinced: If 3-4 quarts of transmission fluid leaked into the radiator, wouldn't the coolant be overflowing? I see no such thing. Actually it was kind of low, so I had to add 1-2 quarts a couple of weeks ago. And I've seen no coolant leaks, either. Go figure.

Reply to
Svilen Stoicheff

I don't buy that at all. Take it somewhere else. ATF in the cooling system is very noticible. It tends to accumulate in the overflow tank. Is the tank oily brownish inside or full of ATF? Take a hose off, is the insides of the hose and radiator covered with brownish oily stuff? Conversly, when the engine is off and the trans is no longer under pressure, the cooling system is still pressurized. The trans would probably get coolant in it.

Reply to
=?x-user-defined?Q?=AB?= Paul

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