car is abruptly shaking
 

So i turn on my car, in park, turn on the air conditioning and the car is vibrating too much. Also when I'm driving, and come to a stop light, the shaking gets even worse. Anyone know what's the problem? Couple co-workers think its the motor mount, others think when i turn on the air it could be the coolant, maybe need a reflushing; i dunno. Any related experiences; do tell, and help me solve this issue. [most certain im gonna be responding late to this, gotta start my route again] thanks scionlifers.

What RPM is it idling at?

at idle power brake the car while having someone look at the engine, there should be some movement when a load is put on the engine but if there is excessive movement its probably an engine mount, turning on the a/c will increase the engine load therefore increasing the rpm so that could just be enough to cause the shaking

How many miles? CEL?

Did you recently disconnect your battery? or did the batt. drain out? If so, give the ECM some time to relearn the parameters. Our throttle control system is drive-by-wire and it may need some time to readjust, even with A/C on during idle. ECM also needs to relearn the pwr steering inputs as well. Ofcoarse, this is all speculation. Since you live out in the deserts of Arizona where gravel roads are common, you can check out your air filter and clean your MAF sensor with electrical cleaning solution.

I had similar symptoms. I replace my air filter and cleaned my MAF sensor. No hesitations afterwards.

My TL does the same thing it never happened in my TC. just let it warm up for about 10 minutes before you go and it wont do it.

1600-2000

yeah we did that at one of my stops. they said the engine did move quite a bit. but what woulda caused my engine mount to give up?

2007 tc with now 72000 miles. cel b/c i have a fujita intake, but now its been off for awhile. the battery may have drained out too, b/c i have a rockford fosgate p2s, and i used to just turn my car half way on, instead of it running on the alternator. maybe, ya ima have to clean my whole engine bay.

mine did the same thing now when i turn my ac on no cold air but also no vibration so idk go from there ..... it must be the ac in some way

the engine mount might not have been tightened all the way causing it to loosen or break, it could be corroded to the point that it broke, take it to a shop to get it diagnosed

wtf?!!? 1600?? am i the only one who thinks this is weird.. my car idles at like 800-900rpms..

It really depends on how long the car has been on and how hot/cold it is that day. When I start my car up in the morning, its pretty cold and my car idles at like 2000 RPM for about 10-20 seconds then slow drop down to about 900-1000 RPM. The engine is just warming itself up getting ready for some driving. Its not a big deal.

That's because it's warming up.

If OPs car is idling at 1600-2000 RPM, something is very wrong.

Ya, when i turn my car on, sits around 1500 but after a bit it is 800-900. The A/C causes vibration in my car but I just live with it.

Also, what do you consider 'vibrating too much'? I idle at about 580-630, and with the A/C on, I can literally see my steering wheel vibrating, and I think that's fine.

You guys should check your spark plugs and run some injector cleaner through your gas tanks BIG TIME. It is a 4 banger but my xB is nothing but smooth and at idle it is scary smooth with the intake shaking the most from the air pulsing into the engine.

I think carbon has stiffer motor mounts, in which case the car will vibrate more. I dont think the car needs a tune up, lol

I have an engine damper and my car vibrates a little bit. Its gotten better than when I first had it, but im guessing its because the damper is looser/broken in a bit.

Yeah I do, but what I was trying to get at, was that his opinion for 'too much vibration' is different than others. I personally like the fact that my car has some shake to it at idle, whereas he might think ANY vibration is bad. All tCs have a slight vibration at idle when the fans/AC kick on and he might think that vibration isn't normal.

maybe op has polyurethane motor mounts or a torque dampener and he's failed to mention that to us.. lol

Are we talking "can't see out the rear view mirror" vibration or my fingers are a little blurry on the steering wheel vibration. These engines have balance shafts in them so they should be pretty smooth at most RPMs.