Is there a common or known problem that causes the engine to vibrate ALOT when the air is on? Its during idle or very low speed driving through a parking lot.I do have the typical 4 cylinder shake of a high mileage car,but I wanted to find out if there is a very common issue first.I once had a car that the a/c bracket was known to crack and it was upgraded in later years.

Just wondering about the accord I have thanks. 96 EX 5 speed Vtec.

Runs awesome,air blows ice cold..wonder of motor mounts might be the cause.

TY for any ideas.

 

Motor mounts, usually front and/or rear can cause excess vibration.

Also, if idle air control valve is dirty, the idle rpm may sag below set point (about 750-800 rpm), and vibration will be worse.

Suggest inspecting mounts visually for damage, and cleaning IACV, throttle plate, and throttle bore. See DIY forum for additional info.

good luck

 

Thank you. The IAC and TB bore is dirty,and can use some cleaning.I haven't gotten around to it yet but recent inspection of the TB bore showed me it hasn't been cleaned out in many years.I used to tear down GM TPI engine and clean the Runners and Plenums for Corvettes and F car owners years ago. Time to start doing my own cars lol

I will check the mounts on further inspection. Not really a problem right now,just more of an annoyance.

 

I had an issue on a VW years ago - somewhat similar.

Crankshaft pulley with the vibration-damper rubber between pulley & hub. That was just beginning to deteriorate but hadn't started slipping. Anyway, when the AC clutch engaged, the crank pulley would wobble visibly. That might not be your problem, but it's free & almost painless to check & rule it out.

 

Thanks...My Crank pulley is old,and when I changed the timing belt recently,I made a decision to get a new one soon.I would imagine the extra load on their would cause the old unit to vibrate some more.I will keep you all posted.

 

I think this year has the electronic motor mount that gets softer at idle. If the idle is too high, it can cause vibrations because the motor mount is in stiff mode...

Another data point, not a diagnosis

 

That vacuum-operated engine mount is only on auto-trans cars.

 

DOH! You are 100% correct, ID 10 T error, failure in reading comprehension on my part