Slight bucking on the highway when letting off the gas and lightly applying it again.

[greenbeanmtx]

As the title says ive been getting this since i got the car and was always told it was the tranny mount. My motor mounts are stock but were replaced july of last year. This bucking im getting is so slight that im the only person who notices it when in the car. Ive become **** about how this car drives and since the alsfb install i notice it more so now i want to make it right because im tired of being ****. Ok so heres my question. Should i get a tranny mount and leave it at that or should i replace the front motor mount with a reinforced one or what? Ive got spring break next week so im going to be doing all this install stuff and i want the car to be perfect when im done so this is a pressing issue to me. I dont rag on the car at all and honestly only open the secondaries a couple times a week or so because im trying to conserve gas. All my mileage takes place on the interstate and when i go over a hill and let off the throttle and then lightly reapply i feel the slight almost hesitation like buck. My freinds think im nuts cuz they dont feel it but i think if anyone knows greenbean its me hehe. With that said im not a track freak and my motor mounts have roughly 15k on them so they should be fine.
Im just wondering what is best for the car. Also wondering how difficult it is to change a tranny mount. From what my search gathered everyone gets them from SHONUT so if yall give me the thumbs up ill go ahead and order one tonight or tomorrow so that it will get here by next week for install time. Thanks everyone

 

[black93sho]

Mine was doing that same exact bucking when I let off the gas and then got back on it, but it was my front motor mount. Just fixed it this weekend and its as good as new.

 

[DVJ38]

My car does the same thing, but only in first and second. It lunges back and forth when letting go of the gas. I've been avoiding this by pushing in the clutch and braking or putting it in neutral and braking. I can't let the engine brake the car.

I was thinking tranny mount. I was talking to my friend and he told me it could be a gasket between the tranny and engine. I've never heard of that before. He also said it could be the shifter rod bearing (which hopefully will be replaced soon, SHOrt throw)

Let me know what you did to fix it though, as this bugs me a lot. Good luck.

 

[greenbeanmtx]

Mines not that severe but ill let ya know what i do. So far i cant get teh correct tranny mount so im toying with the idea of a reinforced motor mount to fix the issue.

 

[sdpatt]

You might have a dead spot off-idle in the throttle position sensor. The mounts aren't causing this condition.

 

[greenbeanmtx]

That occurred to me Scott but i replaced that in september when i accidentally broke the old one. And if thats the case then the tps has been doing this since it was put in the car. Should i go ahead and replace it and see?

 

[shojuan]

That occurred to me Scott but i replaced that in september when i accidentally broke the old one. And if thats the case then the tps has been doing this since it was put in the car. Should i go ahead and replace it and see?

Sometimes you get a bad one when you buy new. I think autozone might be able to test these. If you have an ohmeter you can try to test it yourself by seeing if the resistance changes with position in a smooth fashion or if there are rough jumps.

 

[jelloslug]

You might have a dead spot off-idle in the throttle position sensor. The mounts aren't causing this condition.

Would there be any other symptoms? Mine has always had a slight "bump" when you press the gas, no matter what gear. The tranny mount and the TPS are the only 2 things I can think of that have never been replaced on my car.

 

[Ishodu]

Are you guys maybe feeling the gear lash in the tranny?

 

[greenbeanmtx]

Are you guys maybe feeling the gear lash in the tranny?

I dont think thats what im feeling. Heres a more precise description of what i feel. In 4th or 5th gear on the highway if im in traffic or if im comming over a hill and i let off the throttle to slow down to maintain speed its fine and smooth, but as soon as i re-apply the throttle it feels like its got slack in the drivetrain almost like on a rear wheel drive car thats got bad u joints. No body notices it in the car when riding, only me. But the thing is that every other car i drive doesnt do this. Even the 89 ive got with 244k doesnt to my knowledge.( havent driven in in a couple months so i can recall now for sure)
If anything its just mind boggling to me cuz everything on the car is 100% and maintained. I replaced the tps with one from oreilly and i suppose it could need replaced. If Scott points me to that then naturally im going to listen. If he suggests it then i dont even question it. I will buy another one tomorrow and try it and see what happens. I inspected my tranny mount today from the wheel well and it looks ok. Theres nothing missing but it does show its age. No breaks that i could tell but i didnt study it too close( i was putting new brakes on so i didnt pay much attention). Today comming home from class it did it really bad, to the point where passengers would notice. When this happened it made me see what Scott suggested as being the culprit.
Its not a big deal but if i can resolve it then id like to cuz it just makes the car not feel as solid as i know it is you know. Ive poured all this time into this car and i want this to go away if its possible. When i first noticed it i thought( spark plugs or wires) I replaced, no improvement. Then i did everything in my sig, again no improvement. So it leads me to think tranny mount or tps sense Scott suggested it. Ill pick another tps up in the morning and try it and see what happends but if anyone has any ideas please chime in. I thought i was the only one who had this problem but looks like im not alone so mabe we can figure annoying gremlin out.

 

[jelloslug]

Are you guys maybe feeling the gear lash in the tranny?

That's exactly what it feels like but helical cut gear don't really have much backlash. Also, when I did my 3.2 swap I replaced every gear (including the ring gear) and shaft with new parts and I still have the exact same bump that I did before I didi the swap.

 

[sdpatt]

Before replacing the TPS (under warranty?), you may first try loosening the TPS mounting screws and changing the position of the sensor. It can move a tiny amount in its screw bosses and this is how you set the idle output voltage to less than 1.0V. You should relearn the idle speed programming after doing this.

 

[DVJ38]

My sound is a clunking sound. It only happens in first and second gear (not noticable in the other gears-forget if it happens though). It doesn't occur when I'm on the gas, only when the engine is in gear and I'm traveling and I let go of the gas. If I transition part throttle to no throttle slowly, that I can minimize it. I've been thinking tranny mount?

Any ideas?

 

[greenbeanmtx]

Alright fellas heres the verdict. I went and got a another tps sensor and threw it on and drove on the highway today and the bucking is gone. Scott hit the nail on the head as always. I never would have thought a slack feeling would be caused by a sensor like that especially since mine was new but it was. Thanks Scott i owe ya one! The car feels like i wanted it to now and theres 0 slack of anykind now! No more being ****, yipeee

 

[SHOblime]

For anyone else with this problem.....if you are in 5th or 4th gear trying to go up a hill and you happen to drop below 2k as you shift, that will definitely cause some bucking, I shifted into 5th the other night going up a mountain and boy did she bog/buck/stall a little....not sure if this helps anyone else, but shifting too low will definitely cause a bit of a bucking feeling.

 

[rangerj]

SHOBLIME,

The bucking you feel in high gear and low RPM is the engine bein "lugged". Lugging the engine is ******* it, especially the bearings. So, at slow speeds downshift and keep the RPMs up around 2000 as a minimum and you will not get the "bucking".