I have a 2002 Blazer 2-door LS (4WD). I've owned it about 4 months now.

Last night I had an issue that only happened one time. On our trip to the restaurant (15 MILES), everything was fine. When we left the restaurant for the theater (9 MILES), the transmission seemed to slip ever so slightly in DRIVE as I released the gas. Happened a couple times going around 40 MPH, and a few times later on the expressway doing about 60 MPH. If I put it in 3 it didn't seem to happen. On the way home from the theater (23 MILES), I specifically tried to recreate it in DRIVE, but couldn't. It also ran just fine into work today (15 MILES).

Not that I think it makes any difference, but two weeks ago I went to the local Chevy dealer and had the transmission and transfer case fluids replaced, as well as replaced the spark plugs and wires (don't know if the previous owner did any of that maintenance, so had it done).

I'm open to suggestions. I'm not a mechanic, and it's possible that what I felt as a slip was something completely different. I also thought bad gas, but it has a 1/4 tank when it happened, and it started as a full tank.

Thanks in advance,
Dean from Mukwonago WI

 

so when you got off the gas is when it happened? when you get off the gas do the revs go up a bunch or just like 100?

 

No, to be honest I didn't see any change in the RPMs at all when it happened. I was specifically looking at the tachometer a couple times hoping to see something.

The best I can explain it is a quick thump sound, and a jolt as if I layed on the brakes really, really quick, but with no change in RPMs or speed.

It was very weird.

 

might want to check your u-joints. you could have one going out if all you are noticing is a sound. does it bang or clank when you get back on the throttle?

 

No, nothing like that. Thanks for the input.

 

tranny/motor mount???? thats all i can think that would cause the thump sound.

if its an engine mount, the easiest way to find that out would be to pop the hood, put it in drive with your foot on the brake and give it a little gas, you dont need much, and see if the engine moves alot. you will notice it if it does. then you can go from there.