I have a strange problem. When I am driving everything seems fine, I get on the highway and bring her up to about 60+mph, when I let off the gas, about 1 second later the car starts losing mph and I can feel myself being pulled forward in the seat. It'll do this to about 45mph, then it switches to 3rd gear and I cannot feel it anymore. I counted the gears and it is in 4th after 45mph. I had this problem before, last month I changed the oil (mobil 0w-40) and re-worked my front brakes due to a squeak ( I relubed the caliper guide pins and laced it with desqueak) I did not experience the problem after that, until today. This weekend I did have my tires replaced and an alignment done. What do you think? something with the front end suspension? brakes? fuel filter? I have autotap so I can get data if needed.

 

kind of sounds like the breaks may be sticking a little on the front but hard to tell without actually driving the car. Maybee lube them again and see if it fixes it again

 

yeah i would clean all of the brakes, front and rear,wire brush where the brake pads meet the caliper holder and put some teflon grease on the sliders and pins and the holder, and also on the backing of the brake pads. inspect everything, make sure everything moves freely. you may need some new pads and rotors if they were dragging. and if your calipers are old you need to replace those because they get gummed up with dirt and brake fluid.

 

what is the tach doing as you decelerate? Are you sure it is not stuck in a lower gear?

 

I kept an eye on the tach and it was dropping as my mph dropped, then I see where it switched to a lower gear around 45mph or so. But I will have to check again on my way home today. Strange thing is it acted up this morning on my way to work and my way home for lunch, but it did not act up on my way back to work from lunch. think i'll have to hook up the autotap and take it for a spin and see what gear its on when its acting up.

 

just to follow up, I still had the problem after I change to the ls1 brakes. I noticed sometimes when I started my car, the rpms would take a longer time to go back down to normal idle. I pulled the intake elbow and sprayed seafoam deepcreep into the throttle body, giving it a good soaking. Put it back together and cranked it up, smoked up a storm... the car has not had any problems @ highway speeds since and it idles more smoothly. If the problem returns I'll let you know.