Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

1999 Venture Transmission

Our auto transmission in our 1999 Chevy Venture gives a jerk/jolt when it shifts through the gears as we accelerate. However, this does not happen all the time. When I first start the car, start moving and reach the speed limit, everything works fine. But, if I come to a stop light/sign, THEN accelerate, it shifts real hard and you can feel the (jolt/jerk) change in gears as it moves through 1st, 2nd, 3rd, etc. To make it more complicated, sometimes this this problem won’t happen at all while driving, other times it happens after the first time you come to a stop and accelerate again. There is also a high pitch whine you can hear when the problem starts. When I reach my destination and park, turning off the car, then come back later, the car shifts normally again. OR, I can pull over and turn the car off, wait a few minutes and start up again and that seems to “reset” everything back to normal until I have to come to a stop later. The van has 220K and the motor was replaced at 154K. Could this be a computer related problem. THe CHevy dealer talked about a rebuild at $2-$3000. Have been driving this way for a couple years, but it seems to be getting worse now. Help.

When was the last fluid change?

Had it changed several months after the problem first happened, but it didn’t have any effect on the problem.

When did the problem first happen? At what mileage?

What you really need to do is have the transmission scanned by a shop that specializes in transmissions - a local shop, not a national chain place.

I’m going to bet that you have a P1811 code stored. This is a code that won’t illuminate a check engine light and most likely won’t register on a regular OBD-2 scanner.

Your description sounds exactly like a very common problem in these transmissions which has to do with the computer detecting shifts that take too long. It then maxes out the fluid pressure providing the hard shifts. (I know this b/c I have one of them).

If that trans has 220K on it I doubt that anyone will do anything to it that doesn’t involve tearing it down (i.e. a rebuild). But get it scanned and you can report back (include the very exact and specific codes).

You need to have the computer scanned for codes first,


Had it changed several months after the problem first happened, but it didn’t have any effect on the problem.

Yea, most people do that. The problem is you need good fluid it in to prevent damage and it is too late after the damages shows it’s ugly head. Even if the manufacturer is silent on this issue, I recommend automatic transmission fluid be changed no less than every 30 or 40,000 miles.