Strange issue...

[Eric VerValin]

Ok.. I have this 'thing' goin on that I've been trying to diagnose. I have no codes going off, and the motor sounds healthy like it should. But here is my problem...

When I'm driving.. (any gear) and let off the gas pedal, the motor feels like its missing a front motor mount. It "sets down" really hard, like a broken MM. When I touch the gas again, it "bounces" the other direction. 90% of the time, it dosent matter if theres a big load on the motor, or if I'm really really really easy on letting the gas pedal up. It still bounces around like a bad mount.

In the driveway, hood up, Parking brake on, letting the clutch out in first, or reverse, the motor moves a fraction of an inch, but nothing like a bad mount. I re-torqued the bolts on the mounts, and the subframe just for fun. Still does it.


Now I'm thinking this is something ''vaccum'' related, but being as there is no 'pcv' valve, just the hose, the only other thing I can think of is my throttle plate spring is funny some how, or maybe the IAC is sticky?? Its really annoying driving, because every time I let off the gas, its like I downshifted a gear, and when I ease onto the gas again, it feels like I floored it with a broken mount.



I know my IAC is getting older, and could be a culprit, and the only other known issue, is that stupid donut gasket is leaking again, and I know I'm losing some backpressure there. I've been checkin connectors, and sensor's everywhere, and still nothing. I almost thought I had a dead spot in the throttle position sensor, but it tests out okay.

Anyone have any ideas?

 

[Ishodu]

Play in the CV joints would be my guess.

 

[marv]

halfshafts

I am about to put in my 4th set of axles. Every time I put new shafts in problem,
same as yours, goes away. I put in shafts myself and thought it was my mistakes causing bad axles but mechanic did last time.....I wish I new.....

92mtx-every bolt on

 

[Lightning]

Have you checked your subframe mounts?

 

[Eric VerValin]

Well I have 2 new halfshafts.... like less than 500 miles.. not new, reman, but still.. I'll have to check it out as I'm stuck at my friends house due to snow. Now where would the play show itself? Inside or out?

And I have Aluminum SFB's.. Appeared to be tight still last I checked.

 

[Mad Celt]

Stock tranny/engine mounts? I'd still suspect them...the difference in torque at idle (or whatever low rpm you're testing it while parked) is going to be much much lower than what gets transferred to the mounts even when cruising at 2k. Just a thought as I know VW mounts can look fine and feel fine in the driveway, but can still be smoked.

YMMV, good luck!

RJ

 

[itwonder]

Could it be a front strut rod popping; maybe you have the problem where the socket needs to be reinforced?

 

[Eric VerValin]

Well I swapped out a tranny recently, and in doing so.. replaced a few bushings.... They seemed tight, I used a 3/4" impact on everything. And at the same time, replaced both halfshafts. Wonder if those 2 bolts came a little loose in the center bearing support?

And my rear mount has less than 5k on it, and the front is a used maybe 15k reinforced mount. I had to "reinforce" my tranny mount, as it was found to be toast when I swapped the tranny, and also, I couldn't figure out how I got that damn dampner (shock) back on there.. wanted to cut that peice of frame out.. Got tired of it, knowing it'll be in there when I replace that mount.. (got a friend who knows where a shiny new one is)


Edit: Also have new endlinks on there too.. just werent on for the pic. Just glad to have burnt / pressed the old ones out. man that was fun! and smoky

 

[Eric VerValin]

So I'm about to check this out.. how can I check that socket? The one up front I'm assuming... will it seperate with an obvious crack?

And I also noticed today driving.. It's non existant below 1500 rpm, but up around 2k its there all day. Going to check what I can see visually tonight, will post updates.

 

[93rev2sev]

Wheel bearings?

I know you just replaced those too...but weren't you haveing a problem with them a while back?

Hows the torque steer? Especially in the wet or snow?

 

[Eric VerValin]

Well, not really any more torque steer than I'm used to, feels like a lot less. I definately pulls straight sideways now, as opposed to the old, flex then move. If that makes any sence.

Another thing that is the crazy part to me.... and why I'm thinking along the lines of a sensor or something, I had it for a while where it *should have been doing it, but wasn't, I let off the gas, and as smooth as pie, nothing not a nudge at all. So I slam the gas down, nothing, same smooth gravy. I repeat this a few times, not quite so hard, but then out of the blue, its back, just as bad as ever. No real change in engine speed / vehicle speed.. same gear....


Its just weird to have it **** so hard, when I'm easy on the gas, and not **** at all when I am... (note this is not ''common") It's just so on/off its drivin me nuts.

 

[Eric VerValin]

Well.. the only thing minus my 'bolt thru' transmission mount, is a loose inner tie rod. A good friend has helped me and found me a brand new Ford Tranny mount, so I'll be able to tell if that was it when it comes out.


Also.. the Moog Strut rod bushings... when I was looking at it.. the inside half of the front 2 bushings aren't making a 'flat' contact against the frame... is that the "frame damage" that kit would help? I didnt have my camera, but will take pictures in the morning.... Looking from the front... O's are bushings...

O <-----These half's------> O

Arent' contacting the frame at the outer edge of that "half" of the bushing. Granted its in the hole, and was tightend with the subframe out of the car, and using a 3/4" impact until they stopped.... should be tight right?