DTN

My steering wheel vibrates up and down at idle. It vibrates ALOT. More then any other car I've ever seen. It vibrates up and down, not side to side or turning. It's been getting worse over the last year or so. It's only at idle, if I increase the RPM to 1,000 it completely goes away, then when the idle drops down to 800 again it shakes like a muthafukka.

I've replaced the following list of parts with no change: TPS, MAF, IAT, FPR, Front/rear rollstop mounts

I've torqued the rollstops, motor mounts, and subframe to specs. I've checked for engine-chassis contact.

The inside of my exhaust tip keeps getting black alot quicker then I'd expect, but then again, that may be normal.

I've done regular maintenance. I've changed the spark plugs, wires, fuel filter, all the stuff in the maintenance book. The car runs great.

It started off as the A/C was the only time it started shaking. Now it's always shaking and gets ALOT worse when the A/C is turned on. About 5 months ago I visited the Hyundai dealer and they said to wait until the A/C compressor goes out.

My engine does not seem to vibrate all that much, but it is directly causing the steering wheel to vibrate. when I loosen the rear of the subframe, the steering wheel stops vibrating.

I've got a new A/C compressor and an engine damper on order as a last ditch effort to try to fix this problem. I really don't know what could be causing it and I don't think either of those parts will fix it. I need more options to check guys. Help me out, open your traps and throw out some ideas. I will check anything you say.

HyundaiKitCoupe

the same thing used to happen to my car back when it was an automatic. it used to only shake at idle when the rpm's dropped to 800. the wheel shook up and down more when i pressed the brakes, even more with the lights on, and much more when it was cold outside.

it did go away when i hit about 100k miles. after i got my manual swap, it completely went away and haven't seen it since. now it idles beautifully straight at 1000k like a champ.

judging from what i've experienced, i think it's a power issue. it's hard to say though. i would recommend you adjust your throttle idle up just a small hint and see if that works.

REDZMAN

Dont' you have solid mounts and a engine damper?

DTN

No. I removed the solid engine mount (rear rollstop) and replaced front and rear roll stops with new aftermarket from Advanced Auto. I am still waiting on my engine damper to get here.

I am going out now to do some more troubleshooting. I will try the throttle adjust.

Ericy321

If anything the engine damper will make it worse I would think. It sounds like a power issue to me as well. Is it worse with more accessories on?

Have you tried removing the steering wheel cover? nana.gif

DTN

^^ Funny you should mention that, the steering wheel cover is off!

Ok, so I adjusted the idle up, and it just did that funky rolling idle thing when decelerating which Tibs do when they're adjusted too high.
I adjusted the idle up further and got a CEL
I adjusted the idle down lower and got a CEL
I adjusted the idle back to a normal level.
No change throughout the idle

I tested my compression a while ago and it checked out good

What will happen to the car when you disconnect the vacuum line to the FPR?

Just for fun I disconnected it and the idle raised up. When I plugged the vacuum leak the idle went back to where it was before. Is this normal?

stealth

I have the exact same problem, mine used to be when the a/c was turned on also but it does it almost all the time now at idle, im at 86k miles, and have found that when i have my neons on it gets worse

also when i come home at night and go to shut my sunroof or windows, if i hold the button in after the window/sunroof is closed my idle will go crazy and the wheel shakes like a b*tch until i let go of the button

i also believe it is a power problem and have been thinking that maybe the alternator cant keep up???? just a guess at that

i was going to order a high amp alternator but dont have the funds right now to see if that fixes the problem, any ideas here?

DTN

oh, no, I've put in a new alternator twice. I received it from JavaGeek. The first one made a funny noise, the company who sold it to him honored the warranty and sent me a new one which did not make a funny noise. It is not electrical related.

Any other ideas?

I'm kinda wondering about this FPR thing... How can one test the FPR? What should happen when you disconnect the FPR? Can someone go out to their car, warm it up, disconnect the Fuel Pressure Regulator vacuum line and tell me what happens when you plug the vacuum leak?

Mine raises in idle when the FPR is disconnected and then goes back to the same when the vacuum leak is plugged.

AGreen

The FPR is supposed to have manifold vacuum to it so it can lower fuel pressure at low engine loads (full manifold vacuum) and raise it when vacuum drops (i.e. the throttle opens)

If there's a vacuum leak, which I'm assuming you will have because you pulled the vacuum hose off the fpr, the the idle will go up. It's almost like opening the throttle a little bit, but it's unmetered air so it will throw a CEL if not taken care of soon. You really shouldn't notice any difference in the way the car runs with vaccum removed from the fpr, so long as you don't create any vacuum leaks. The only way to test it is to attach a fuel pressure gauge to the fuel rail somewhere and snap the throttle. If pressure goes up when the throttle opens, it's good.

I really don't think it's fpr related. I don't recall seeing any beefed up ground cables on your car when you were here last. Check voltage drops all around while the car's running. If you have those cheesy bolt on cable ends, get them replaced with good crimp-on's, and heat shrink the connection.

I learned to live with my vibrations. I think the 1.8 cam and high comp. pistons, coupled with filled front and rear motor mounts are the roots of my problems.

DTN

Ok, I've done some more research on this. Check out this picture



The power steering unit connects directly to the crossmember. If the crossmember was loose, or the bracket which holds the power steering unit is loose, it would cause this problem. Steering wheel vibration has to have something to do with the crossmember. I think it's the key.