intake issues

[mbear2489]

mom has 1996 grand am se with the 3.1 in it. recently driving down the road, it revved very high and wouldnt go above 40. then when it warmed up it was fine.... intake gaskets good, and a mechanic couldnt find anything. any thoughts guys?

[3100 MPFI]

Not 100% sure what causes it, but it is in the transmission.

The 440T4 in my 1988 Cutlass Supreme did it really bad, but it still lasted almost 2 years after it started doing before I finally got around to changeing it out. I just let the car warm up in the morning.

Right now, my 1990 Grand Prix STE does it (4T60) on cold days. I just let the car warm up, and all is good, and it does not do it again until the car cools down overnight.

I think in my older tranny it was brought on by a broken accumulator spring, but in my 1990 STE, I think it is a cracked seal in the 1-2 servo (seeing that the accumulator springs are fine).

[mbear2489]

oh yeah. forgot to add. we took it to aamco and they told us they were one hundred percent sure that it was not anything trans related and it was in incredible shape for 82k. next question, i know intake gaskets are an issue for the motor..... cracked manifolds ever happen/ would they cause that?

[El_Diablo]

of course cracked manifolds happen... but not directly because of gaskets (that ive seen) and it wouldn't cause an issue like that, the car wouldn't want to run, it would be a vacume leak...


highly doubt its an intake problem, what leads you to believe it is?

[mbear2489]

well... everything else vacuum related is good. all hoses i checked, gaskets are new, my question was at the end of last post. do cracked manifolds if its minor cause that kinda thing?

[El_Diablo]

you misunderstood.... if the manifold had a crack, it would cause a vacume leak, not saying the cause of the problem is a vacume leak

[mbear2489]

ah. i see. well its not trans like i said. i dunno wat else would do it

[El_Diablo]

techs aren't always right... most likely they just check the computer and fluid and maybe drove it around a little (most likely while it was still warm)

[mbear2489]

hmmm, well. it hasnt happened again. but we are gonna take it to one shop quick, and if they figure out wat it is, and its bad we are gonna trade it