Does anyone with a V6-T5 combo have or has had this problem:

fixed the vacuum leak, intake and IAC cleaned out and TPS adjusted. I still have "bucking" when slowing down in gear (mostly only 3rd now for some reason whereas 1st, 2nd and 3rd before). It happens when you slow down and get below 1500rpm and she "bucks" forward and back until you either put the clutch in or hit the gas.

Can anyone help me here. I don't know what else it could be as the engine is running quite good now. Why does it do this and why only in 3rd now????

 

downshift, your going to slow for that gear. any stick will buck if you drive do it right / wrong.

Matt

 

yea i had the same problem then realized what i was doing

 

Not to throw a spanner in the works guys, but i have had a LOT of experience with manual shift cars, the only time that this 'bucking' would come about due to engine revs, is if you were forcing the engine below idle.

if you are 'bucking' above around 750 rpm, you may have some other problem, perhaps engine mounts have gone soft?


a manual shift car should be smooth right down to idle.

 

I have to side with grumpy. 1500RPM is way to low. Especialy if you are in 5th gear. It's going to buck and try to die on you. I have yet to see any manule car or truck that will put up with this. My owners booklet states that you coast down to 20 MPH in 5th before needing to depress the clutch, but try and see what happens. The car will protest every step of the way starting at about 30 MPH or so. It's just too steap of a gearing for the engine.

 

Im with philoldsmobile, I go below my idle rpm in any gear and it never bucks, ever, and it used to be an auto and I havent changed the prom. check the timing, minimum idle and the tps if yours is adjustable or maybe its bad.

 

Well part of my problem may that I idle at 1000RPM. Tried to get to factory specs for about 3 and 1/2 years with no luck. No other symptoms or problems just a high idle.

 

that idle definatly has something to do with it, when I switched from the auto I had to reset my idle big time, when I unhooked the IAC it went up to 1500 rpms when it should have been 5 or 6 hundred. find out why yours idles so high and youll find your bucking problem.

 

only if there is something wrong, such as motor or tranny mounts.

even most race cars will roll along with the clutch out, in gear, without bucking.

i had a Ford Cortina (english) with a 5 speed borg warner gearbox, and Rover (buick) 215ci V8 engine. that would pull smoothly from 800 rpm, without any ****** at all, and would decellerate right down to idle in top, again totaly smoothly.

untill you are at (or only just abouve) idle, you should NOT have the clutch depressed, otherwise you loose ALL engine braking.

it is not only a problem with the car if you have to de-clutch at 1500 rpm, its also bad driving.

 

Hm, my old Jeep would buck with the old trans mount. Replaced that and fixed a few vaccum leaks, much better. Smooth down to idle in gear on that old 4speed Borg Warner.

-Dan

 

I got the bucking too. But I'm working on brake and suspension rebuilds, so the engine is next in line.

 

WOW! Thanks for all the replies guys. Sorry for the absence but the cottage was calling for me on the weekend.

As for the point about more bucking especially in 5th, I have actually found the opposite. It is less as you go up the gears and I have actually never gotten it in 5th even before the engine tuning mentioned in my first post. After this work, it doesn't even do it in 1st right down to about 1000 or 900 (the torqiest gear).

I will have to check the timing tomorrow and minimum air as mentioned and post again after that.

What is the idle supposed to be for the V6-T5 anyway???? Mine is at about 850-900 right now. iS that too high??

edit: oh also, brand new tranny mount but never checked the engine mounts. How hard are they to do??

 

they aren't hard, just place a floor jack under the front of the engine (under the crank pully) , and jack just untill the body starts to move (there will then be no weight on the engine mounts) they should then just un bolt

if you can go to idle in first without bucking, i wouldnt bother changing them, as they cant be too bad.

Congrats on geting everything sorted.

 

Well, I checked the minimum air and it was right around 450-500 so that was fine. THen I checked the timing and it was off by 3 degrees (13). So I adjusted that and today when I was driving I didn't notice any bucking in 3rd when slowing right to idle (as mentioned currently 900ish). No bucking in any other gear either. Any ideas as to why timing would fix something like that (assuming that the few times tested already are representative of how it will always act from now on)??

philsolsmobile - for the engine mounts were you referring to taking them out from the top (in the engine bay??? or from underneath? If they are worn, would that cause more vibration at idle felt through the body??? Cuz you can see things shaking on the passenger seat at idle but over 2000rpm it smooths out mostly.

Again though, is 850-900 right for idle for a T5 car??

thanks.

 

ok, unfortunately the bucking is not gone. It seems to mostly occur when cold (and again, usually in 3rd). Once warm, not much, but sometimes. But today when it happened (when slowing in 3rd it started just below 1500rpm) and then I hit the gas a bit thinking it would smooth it out.....it mad it worse Any thoughts as to why it would do this??

 

I dunno if anyone has mentioned this as of yet, but hows the tortion (torque) bar bushing? It's possible it's pulling back and forth really hard from a bad bushing. Just an idea. *shrug* That, and it could be another mount or a bushing some where that might be a cause of your problem. Just a good look over the suspension could be all that it needs.

-Dan

 

nadster - actually, it's a brand new ES torque arm bushing and rubber tranny mount. The engie mounts are possibly original though.

 

sounds like soft engine mounts to me.