Bibi_is_hername

I'm the new owner of a 03 Evo 8. Love everything about the car but you all new that. I ran into a little problem though. While at idle with the a/c fans on I noticed the steering wheel vibrates. Its not unbearable but you can always tell when i have the a/c on? It has DC titanium front and rear strut bars on it. I'm wondering if that stability is what causes that vibration to be more noticable or if there is something wrong structurally. Any one help me out?? Thanks

barneyb

The AC always makes things shake. Yesterday I had my battery disconnected and the ECU has yet to relearn the idle. At stops the idle is dropping to about 600 and I can really feel it.

So, normal.

Bibi_is_hername

I appreciate that reply. Makes me feel a little better about it. The car has hks 280 cams, do you think they could cause the idle to go up and down?? Like you said its almost as if the car can't make its mind up where it wants to idle. My normal idle is about 750rpms but it can range anywhere from 800 to 600 rpms. I'm just trying to figure out why its doing that.

mirkendargen

iTrader: (2)

You might have a vacuum leak(s) or a dying idle air controller if your idle is consistently wandering after the ECU has had time to learn it. (And not just the change of the compressor coming on or off). If you have a solid front motor mount, that makes the steering wheel shake a lot more too. A lot of people do have them because that shake is the only downside, and they improve shifting and throttle on/off response.

But yeah, every car I've ever owned AC makes it noticeably shakier. I mean, car compressors is a back-and-forth piston kinda machine, right? No way to keep that from causing a lot of vibration.

190hpkilla

iTrader: (19)

Check idle speed. Is the RPM at idle too low? Cleaning the throttle body helps bump up the idle.

As carbon builds up on the throttle plate it gets difficult for idle air control valve to keep throttle butter fly open(carbon acts like a restriction)

Disconnect battery( this will reset all computer learned values so your idle wont be high after you clean the throttle body) Dont spray too much cleaner, you can hydro-lock the engine. Use a brush to clean inside throttle, make sure no lint or hairs get left behind(that can cause throttle plate to stick)

If after this the vibration is still present, this means usually the engine mounts are dry rotted and transmit too much vibration(do you have all factory mounts?)

Sometimes you cant tell if the engine mount is bad, I recommend replacing all engine mounts at once, as even one bad mount can cause unwanted vibration,

I had many Evos even with balance shafts removed My steering wheel does not shake.

bluedevil06

four bangers are the worst with the a/c on and the evo's are pretty nasty compared to my other dd's. i assume your car is tune with 280 cams, they are pretty aggressive without a tune and will cause loopy idle.

Bibi_is_hername

I recently unhooked the battery to work on the sunroof so that could be why my idle has been so screwy. How long does it usually take for the ECU to relearn the idle?? Going to look into getting new motor mounts, vacuum leaks, and cleaning the throttle body.

03 Mitsubishi Lancer Evolution VIII stock wheels and tires for sale.
Custom Painted (dark gray) Roll Bar for sale

EvoTeyn

It shouldn't take longer than 10 minutes, try disconnecting the neg. terminal for about 5-10 minutes, reconnect and start her up and let it idle for 10-15 minutes. I forgot to let mine idle and it was all f-ed up driving, especially coming from a stop but it learned itself after about 20minutes. If it means anything mine normally idles at 1k-1100rpms, with AC on anywhere from 700-1000rpms, I usually turn it off when comming to a fast stop. If it still vibrates after I'd check your engine mounts like the other guys said

maevo8

iTrader: (6)

I mys self have the 280 hks cams and its normal for it to do that after instal. At first thought it was the iac going bad replaced that and same thing so I would say your good to go

ixmrgg

iTrader: (13)

If you get motor mounts, prepare to have a lot more vibration when idling with the AC on. I just got a Blox front engine roll stopper, and while its fine through the rest of the rev range, the wheel and dash vibrate quite a bit when stopped at traffic lights and the like.

Bibi_is_hername

I appreciate all the help thanks guys

190hpkilla

iTrader: (19)

What he means is NEW motor mount as his OLD mounts are dry and transmit more vibration.

190hpkilla

iTrader: (19)

There you go. After disconnecting the battery idle will be low especially with all the gunk in the TB.

Disconnect battery again. Clean TB. Connect and it should idle like new unless there are other hidden issues.