Motor or something is shaking while gunning it or tapping gas pedal. Can't Figure out
 

Just replaced all 4 motor mounts with brand new ones. Replaced Manual trani one yesterday replaced the other 3 last month. Engine shakes like 3 times or so when I am going on to the highway or gunning it. I thought it was the clutch for the longest time but Pmohr thought it was the motor mounts. Well replaced those and it still does it.

Def a difference in shifting and drive ability tho since replacing the mounts so I don't regret that at all. Car is so much better to drive and it bucks a whole lot less in 1st gear but wish I can get rid of the shaking when guning it or when trying to shift to 5th on the highway on ramp.

What could it be? Are the mounts just not good enough? I was thinking of digging the old mounts out of the trash and doing a poly mount project but I really had a pain doing these mounts. lol, really don't wanna do them again unless I have too.

What else could it be? IT just seems like the engine is not being held good enough? The rpms stay the same so I know it is not the engine responding wierd. PLEASEEEE help. It makes no sense because the car never did this last spring with OLD beat up/cracked mounts.

I'm kinda having this issue also. I'm going to try out an engine torque damper and see how it goes.
I changed out my axles, motor mounts and all my suspension bushings.

Although, the vibration is not as bad as it was, it's not good enough for me.

Man I think we are having the EXACT same problem. Does it happen when you are in 5th gear cruising at low-to-mid range rpms and you open the throttle relatively quickly? And the motor feels like its hesitating and there is a lot of vibration for a second until the car accelerates normally.

I thought maybe it was just that you aren't supposed to hit the gas that "hard" that low in the rpm band in a high gear. It wont happen if I'm in 5th gear above 3k rpm. It's like the torque is twisting the engine around in the bay. I have ES motor mounts as well and have replaced every bushing with polyurethane except the subframe bushings. After I replace those, I will be out of ideas as to why it does it.

I rarely get it shifting into 5th though. It doesnt happen if I ease into the gas , only if I hit the gas pedal quickly, even if I'm only opening it to 50% throttle.

I almost think perhaps the stiffer motor mounts are what cause it. Maybe on softer ones the motor wouldn't have the same rebound and the mounts would absorb all of it.

Sounds like you have a minor hesitation or misfire going on. Check the MAF sensor response, you'll need a real time scanner to see the signal to the ECU. Also make sure the TPS signal is smooth, you can easily do that with a volt meter.

That is certainly a possibility. I have other drive-ability issues like a sudden jolting when applying and holding the gas very slightly at cruising speeds. I was figuring I had a failing timing-related sensor. The TPS is brand new. Maf is used, just replaced, but still suspect.

What kind of mounts did you buy? I've replaced 3 so far but the transmission mount from idiotzone keeps ripping into pieces... usually the weakest link goes first and I would assume it'd be the older oem mount by the timing chain cover but instead I've gone through 3 autozone trans mounts and I'm actually at the point where if this last one (that I'm about to pick up in 45 min) does not last me 1 month then I'm asking for my money back and if that doesnt work I will call corporate.

Sometimes we'll rule out the fact that its a new part and say "oh its not that, I just changed it last week" and then keep hitting our heads because we cant seem to find what the problem is.. Dave Sz and I took a look at my car I'd say about a month ago when I complained to him about the problem and it wasn't as noticeable but it was def there so we thought it would be something else rather than the mount itself.

My uncle thught this but it cant be, no rpm change and it feels like a violent shifting of the engine, but it would make sence as this didn't happen last spring with OLD *** mounts. but I just did everything tuneup wise to the car.

power pros...

I HAVE THE SAME PROBLEM!!!!

But my mounts look pretty good though.

Has anyone checked out to see it was their maf? Also where would I plug in the voltmeter to check the TPS? Also could it be Iggy coils?

My car still acts stupid with the TPS unplugged. Still bucking during normal driving. I think its either my MAF or some kind of ignition coil problem. I'm not buying used MAF's anymore, I can't seem to get one that lasts for more than a few months. It looks like I'm going to bite the bullet and get a new aftermarket one.

Engine RPM's are fixed to your manual tranny & drive trane. Once your moving you're not going to see any big RPM change with a misfire or hesitation, you're only going to feel it.

hmm... good point, but I figure if there is a misfire you would see an erratic RPM needle

you wouldn't.

sounds like a sensor related problem to me.

my car shakes a little bit but its the car pulling...when i gun it or just push the pedal down all the way in 2nd or 3rd it feels like its losing traction or its going to but its just the pull...i was trippin at first too!! but the car runs fine, check my mounts, axles, cv boots, control arms...everythings fine..

lol all mt 4th gens seem to have this problem from the looks of it, mine does it too, like if i suddenly get on it, it shakes then goes, but if i do it back to back it will shake the first time then the second and third time etc. its fine, i think its a sensor issue, almost like a "system not ready" type thing. because if i roll on it i dont have that problem.

thats weird. What kind of sensor would it be?

Not sure if it is possible with a hydraulic clutch system, but....Could it be clutch slip....I guess from reading this thread so far....from the way everyone is talking about hesitation of power and vibration.

Just try to think outside the box....:).....heck maybe thinking like :jeffy:

I'll go :wall: now.

I just bought a new MAF, so I will report back if it solves any of my issues.

well, i have an auto and it'll do the same thing. so, i think its just a " cars gettin older, just check everything thread" and leave it at that.

yeah, by now I am starting too think it is some type of hesitation, because this "shake" feeling never did it on the old *** mounts. Why would it do it on the new ones? So it has to be some type of hesitation.

when this shaking occurs have any of you felt any type of acceleration or power loss from the car at all? i have a 96 auto and when this happen i feel a whole loss of power anyone feel loss of power?

yes, old car. its probably upper throttle body cleanout, maf clean, idle adjustment. maybe coil packs are not responding as they used to.

yeah.....you don't know, just stop.

hey!!! im goin on expierience here....:hide:

YOU SHUT UP! lol

lol

the new maf definitely did not even remotely help the jerking issue. My best guess is that it is worn subframe bushings and maybe coupled with the stiff polyurethane motor mounts most of us have that are not very forgiving. With stock motor mounts it seems like the motor might still jerk under the same conditions but you wouldn't really feel it as the motor mounts would be more absorbent.

thats my best guess.

^Bump^

Just cleaned my MAF today.

It helped my car in other ways quite a bit, I thought my car was responsive already after the throttle plate cleaning and fuel injector cleaning, but it's somehow even better.

As for the jerking... ITS STILL THERE! But now I REALLY have to try to make it happen, it doesn't happen as much as it used to, I really doubt cleaning the MAF or that the MAF has to do w/ the problem at all now.

Maybe it's just a 4th gen thing...