Vibration in Gas Pedal?!?

[mikec]

Hey Everyone,

Here's one that'll get you thinking: Would an emergency stop be the actual cause of sudden vibration being felt in the gas pedal at any RPM over about 1500 or so, regardless of whether the car is in gear or not (4EAT)? Because that's what I'm going through right now. The vibration is basically present whenever the engine is running, and doesn't correlate in any way with speed, but with RPM. I also believe I can hear the vibration affecting the engine, and the engine doesn't seem to be running at the same RPM for the throttle positions I'm used to. Which leads to what I believe crazy hesitation being experienced, as the car doesn't seem to want to go anywhere on the highway. Having searched for "vibration", I'm wondering if the hesitation is due to the vibration.

So... Any ideas what would cause vibration all of a sudden? Like I said at the beginning, this all seemed to have started after my panic stop. The brakes have been checked, and the pads are at least 50%, and the rotors looked fine. There has been a bit of vibration in the brake pedal when the brakes are applied since it, but I was on them pretty hard, and didn't let the car roll forward when I finally stopped.

Sorry for the long and vague post, but as of right now, that's all I know. Is it just possible that its a coincidence and the engine mounts have deteriorated more than they had before?

[vrg3]

The only way you should be getting vibration through the throttle pedal would be through the cable. I'd check the throttle cable for proper tension and check that the throttle cam is properly fastened and turns smoothly with the appropriate spring tension.

[mile hi]

Something has probably happened to make the accelerator cable tight, there should be a little slack in the cable. I would check the cable where it is connected to the cams that operate the throttle plate. Or possible motor mount ? This would let the motor move a bit and the cable might be tight from this.

[mikec]

I'll check that within the hour or so. I've got a bunch of driving to do, so I'll know pretty quick it that did anything.

Thanks for the suggestions guys.

[Legacy777]

About the hesitation thing.....pull fuse 14 for about 5 minutes and then go drive. See if it changes things.

[mikec]

I'll try that too!

[mikec]

Well, I did some testing. Had to go somewhere, so I took the highway there and local roads back. The vibration is tied to speed, afterall. On local roads, I was able to get the RPM up to 3000, and the vibration was a lot less in 3rd than it was at the same RPM in 4th (speed obviously higher in 4th). Is it possible this is could be the wheel bearing that I thought was going bad actually going bad?

The reason I'm getting worried about this is that I have visions of the engine slowly tearing ifself apart from the inside. If its just something simple like engine mounts, then I'm not so worried. I've got newer mounts coming, but until they do, I'm afraid to push it / drive it at all. I'm also considering a trip to the local dealer (labour costs!!).

Throttle cable looked okay. Slight slack when the throttle was completely closed. I did WD40 the springs and cable, as they were gunky. They didn't feel overly hard to move when I tried by hand.

Oil's good. I suddenly had to add a quart today. Spark plugs look okay, but the plug for #1 cylinder had some oil around the threads and base (the widest part). I've asked about that in another thread. Gonna check tire pressure after they've had a chance to cool. Last tank of gas was 89 with STP fuel injector cleaner, but I've burned a 1/4 tank of 87 since. Dunno what else to offer in the way of information.

Again, sorry for the vagueness and length of this post. Just trying to avoid engine death and a trip to the dealer.