car feals "heavy" after letting of gas

[TimF]

When I'm driving my car, and I let of the gas, my car will coast for a split second, then just feels like it gained 500 pounds and slows down like I'm braking, then just goes back to coasting fine w/o problem. Any Idea what this is. Before it only happened in 1st gear when the car is cold, but now it carried over to 2nd

 

[Calan]

You need to fill out your vehicle profile so we can get an idea of what we're working with.

 

[TimF]

stock, have done nothing to it other than a shift box.

 

[black_gst]

Do you smell hot brakes?

 

[dondmon96]

I agree, drive around for a bit and see if your brakes smell hot after normal driving. Go down a hill and pop it in neutral and see if it does it.

Another thing to check is check to see if your BOV recirculation hose is hooked up right. I drove with a Turbo XS Blow off for awhile cause it came with the car, and when you was going downhill 'coasting' it kinda felt like what you are describing, bucking and jerking.

 

[TimF]

brakes are fine(we inspected them the other day when I changed tires), I dont smell anything. My bov is connected right. I dont even touch the brake and it does it, just when I let of the gas, and it only holds back only for a second or two.

Ill check the coasting downhill in neutral when I get out of class

 

[born2tune]

not brakes, but it could be your wheel hub bearings are going out, sadly more than one at a time. if it was just one then as soon as you let off the gas the car "pulls" to the side its worn, they cause a tight feeling like if the car cant cruise downhill as a normal car would. but if its more than one then it wont pull to one side but instead just slow your car down alot may be evenly or unevenly.

another factor is the Psi in your tires, if its low they "drag" more than one thats normal or over-pressurized.

 

[KMOSES]

I've got the same problem, it only happens in low gears for me like 1st and 2nd, if im in first its much worse than 2nd. It's really annoying in traffic when you are in 1st you get up to 3krpms and right before you hit 2nd you have to slow down and start to coast down and right before you get to the point where the car would roll by itself in 1st the car jerks like you just slammed on the breaks for a split second then continues to roll.

 

[TimF]

I've got the same problem, it only happens in low gears for me like 1st and 2nd, if im in first its much worse than 2nd. It's really annoying in traffic when you are in 1st you get up to 3krpms and right before you hit 2nd you have to slow down and start to coast down and right before you get to the point where the car would roll by itself in 1st the car jerks like you just slammed on the breaks for a split second then continues to roll.

That’s pretty much it, it does not jerk that bad though. I have not felt it in third, it use to only be in first, which I rarely drive in unless I need to accelerate in a hurry, then now it’s in second. It is worse when the car is still cold to.

 

[KMOSES]

That’s pretty much it, it does not jerk that bad though. I have not felt it in third, it use to only be in first, which I rarely drive in unless I need to accelerate in a hurry, then now it’s in second. It is worse when the car is still cold to.

It is worse when its cold for me aswell, I also may have exagerated a bit by saying "slammed" the brakes. It is a good solid jerk though.

 

[jtmcinder]

Do the down-hill test two ways. If you feel the drag both in gear and out of gear, then it's the driveline or brakes. If you only feel the drag in gear, then it's engine-related.

Kinds of thing that can cause this in the driveline are binding in the transfer case, gunky gear oil, or - gasp - a transfer case that has leaked out all oil and is about to seize on you. (You already ruled out the brakes, it seems.)

Kinds of thing that can cause this in the engine are ... ask someone else ... I'm not an engine expert.

 

[Calan]

Kinds of thing that can cause this in the engine are ... ask someone else ... I'm not an engine expert.

Since it is temporary and only when first letting up on the throttle, my first thought was a malfunctioning or disconnected BOV causing compressor surge and a sudden imbalance in AFR...but I'm not sure how likely that is on a stock setup.

Does it do it even if you stay in vacuum and don't go into boost?

How long have you had the shift box installed? Any other mods related to that?

 

[TimF]

Since it is temporary and only when first letting up on the throttle, my first thought was a malfunctioning or disconnected BOV causing compressor surge and a sudden imbalance in AFR...but I'm not sure how likely that is on a stock setup.

Does it do it even if you stay in vacuum and don't go into boost?

How long have you had the shift box installed? Any other mods related to that?

yes it does it in boost or vacuum, and I have had my shift box in for a while now, I say since april. I have done nothing yet to my car other than the shiftbox, and I got that because I lost hundreds over finding a good TCU and gave up on that. I just came back from looking at my fluid. if anything my trans fluid seems to high, my engine is cold and the fluid is up to the hot section on the dip stick.

and if anything it does it more in vacuum then boost actually

Also Im going to my girlfriend in a bit, have not gotten a chance to test it downhill yet

 

[ChiTownHussla]

vacuum leak?

 

[TimF]

I tested on the hill, and on flat road. On the flat road I stayed in first and accelerated a little, then shifted in to neutral, then let of, the car coasted fine. I also accelerated downhill in first, while going down shifted into neutral and let of gas and it ran fine, so I hit the accelerator while in neutral downhill and it went up and came down again. So there was no heavy feeling while coasting in neutral.

 

[born2tune]

so you are saying that the problem went away? im confused whether you did something and you fixed it or you are saying it doesnt drag no more but it still does ?

 

[jtmcinder]

Sounds to me like he just ruled out drivetrain and brakes. Assuming that it still drags when in gear, he just isolated the problem to the engine. Thus, I now bow out and leave it to the engine experts. Good luck.

 

[dj-t]

Same situation with my bros 97 tsi. Every time we jack up the car to inspect we couldn't find anything wrong everything seems fine. Lower the car take it out for test drive. It runs normal again, but after about 15 minutes it will have the heavy drag again in any gear.

Its been about a month know since this started happening he still drives it but very short distance (no more that 2 miles). Now the rear is starting to lock up on him. As he goes up the driveway or make a hard slow turn the rear tires will chirp. It's like having the center diff welded. I drove in his car a few days ago and now it is rumbling from the rear like he has mud tires on. Lifted it back up turned the rear tires to see whats going on it turned smooth no noise nothing. The next thing we'll do is disconnect the drive shaft and see if it is from the front or it is the rear diff.

 

[KMOSES]

I also did the downhill test, no drag while in neutral, the jerk still happened while in gear and going downhill.

Also to the OP, I don't want you to think i'm trying to thread jack, just trying to help get as much information and as many eyes on the thread for the both of us

 

[TimF]

I also did the downhill test, no drag while in neutral, the jerk still happened while in gear and going downhill.

Also to the OP, I don't want you to think i'm trying to thread jack, just trying to help get as much information and as many eyes on the thread for the both of us

no problem cause I really think we do have the same problem. Like stated before it only drags in 1st and 2nd, is worse while the car is cold (if it does do it while the car is heated its not as noticable) and only in vacuum, Iv went WOT and boosted and no drag after that.

 

[Colt4G63 also]

It sort of sounds to me like the transmission isn't automatically upshifting when you let off the gas. Kind of like when you shift into low two when going down a hill to help slow down the car. Downshifting in laymans terms. How long have you had this shift box?

 

[bryanwheat]

I agree, it sounds transmission related. Maybe the converter is staying locked for a second or 2 and than unlocking or something along those lines. I couldn't see it being engine related really.

 

[98GSXtacy]

Have you checked you transmission fluid yet by chance?

 

[EZSpeed]

is it auto or manual? maybe we're overthinking this and it's just engine braking, or downshifting like Colt4G63 Also said

 

[bryanwheat]

It is an auto.