when i turn my ac on and the engine is pretty warmed up, a tapping/clicking/knocking noise starts. it almost seemed like the velves but it doesnt do it every time. only sometimes but when i turn the ac off then it stops. what could it be? i went to a mechanic and he sad that its juts the way the engine runs when it has the extra load of the ac when its on... ?? it seems a little too loud for it to be normal...does anyone have a clue what it could be? it sounds like its coming from around the left side of the valve cover, near the distributor...
thanks a lot for any and all help
TIA
-Tom

 

hmm strange problem. if it's loud it shouldn't run like that. is this at idle or when you are driving between the cruising ranges of 2500-3500 or is it in vtec?

check on the interals of your distributor and make sure things are tight in there -- like the rotor, etc.

that's a start anyways, HTH

 

OK I'm just GUESSING here so don't get mad if its wrong... but since you say its ONLY when the A/C is on.. and stops when the A/C is off.. it might be your A/C compressor/condensor or the associated belts or pulleys for the a/c?

 

My car runs like **** when the ac is on, but, i don't hear any ticking.

 

my car makes the same noise also...it only does it when the a/c is on...i dont see anything wrong it really doesnt bother me i think its normal...my a/c still works perfect but ya mine does the same....what kind car do you have?


[Modified by CiRcUiTsi, 11:55 PM 8/3/2002]

 

sometimes that's what a 'sig' is for

 

my bad i didnt see his sig haha oops

 

sometimes tapping sound is from the oil pressure being too low. I had the same sound when I had my oil cooler system hooked up. As soon as I disconnected the oil cooler the sound is gone. A/C might lower the RPM & that might cause additional oil pressure drop. Low oil pressure will create a valvetrain noise.
That's my thought. Does the tapping go away when you raise the RPM slightly?
Yuri K

 

Try running your car uphill and see if it still happens. If not then it is your AC compressor or the AC clutch.

 

is the tapping coming from the engine bay??? or passenger side near fire wall..might only be the fan if its associated wiht the AC

akams razor.....simpliest explanation is usually the correct one--but that isent alway the case wiht cars

 

my car does the same thing. i took it to a mechanic and he said dont' worry too much about it. its nothing. so i was like ok....if this **** messes up its on YOU.

 

my car makes a whining or whistling noise when my a/c is on. it kinda sounds like a jet firing up. its kinda neat sounding but i'm hoping its not something wrong. do any of you know what i'm talking about? when i cut the a/c off, its still there for a little while, but then it fades away after a few minutes?

do any of you know what it could be?

 

its just your fan cooling down the engine. its nothing wrong. every car does it. the longest i've heard the fan going is my friends benz. its on for like 10 minutes. i know what your talking about when you said it sounds like a jet or soemthing. its nothing. its supposed to do that. its also better to have your a/c off before you turn off your car. or when you run your car hard you should leave it running for a little bit after before you turn the car off.

 

oh...i meant leave the engine running on after you run your car hard....not the a/c. heheh

 

thanks for the responses guys,
i thought it was from the ac compressor or the belt or fan, its cant be because it comes from the other side of the motor. it is from the engine bay, the mechanic told me the same thing, its ok and "normal" so im not gonna worry about it unless a problem occurs.

 

Yea mine does the same thing with the Ac on.I assume normal.

 

maybe it's the A/C compressor making noise?