HELP! weird sound from engine when defroster is on

[EliteConcept]

today i had to use my defroster on my 92 X. I put it in park and got out while it was still on.....and i heard a weird sound coming from the engine...it quit when i turned off the defroster....and came back when i turned it back on...
it sounds like the pully under the hood is attempting to start spining...but as soon as it starts like it is spinning...it shuts off...and repeats this process every 3-5 seconds, while the defroster is on.

anyone know what could be wrong with my truck???
if so how and what do i need to fix it??
please help!!!

ryan

 

[TDG]

Does your A/C work? I only ask because when you turn the defroster on it also turns on the A/C to help dry out the air. Try turning on the A/C by itself and see if the sound returns.

 

[espnfreak]

yeah like he said, its most likely the ac compressor running

 

[mattadams]

is it like a loud clicking? That's just your a/c compressor shutting off and on. It freaked me out a few times too because sometimes its so quiet you can barely hear it, sometimes its very very loud, no explanation for it.

 

[EliteConcept]

I just had the a/c recharged before i went to airzona in june and it really didn't work too well after i got it recharged... i noticed this sound then too....
when i turn on the a/c it also makes this sound.

its almost like a clicking grinding sound..like the pully can't move....if watch the pully or what ever the round thing is called the belt attaches too....that emits the sound...it will begin to spin....then stop.

any ideas?

thanks so far for your help!!

 

[TDG]

If its every 3-5 seconds then the compressor is short cycling, probably due to a low charge. If it's making a ton of grinding noise then the compressor is probably shot. Chances are you had it recharged due to a leak, and when the A/C leaks the oil that lubricated things such as the compressor leaks out too. (You can usually spot an A/C leak by an oily residue near the leak location) Chances are if they recharged it and didnt add any oil your compressor may be gone. My 93 makes a ton of noise when the A/C is on due to being improperly serviced (Orifice tube in backwards, no oil in the system etc) before I bought it. The last time I tested the compressor it wasnt able to maintain proper system pressures. Either way take it back to the A/C people who recharged it. If A/C isnt an issue at this time of the year and you just want the noise to go away when you turn on the defroster then you can disconnect the A/C clutch coil, basically locate the spinning, whirling, grinding thing and find the two wires going to it (Should be behind the pulley) yank em off and tie them back out of the way. Of couse there are a zillion other things you can yank and pull to keep the A/C from coming on but thats the simplest one I know of. But who knows? It could be something very simple.

 

[EliteConcept]

as far as the air condition recharge my girlfriends mom knows the guy who did it as a favor...... but it probably needs to be done again next year?

ANYONE KNOW if there is a problem if i disconect the wires from the pully that makes this noise??
like tdg said????


thanks
ryan

 

[kps36]

This happened to me.
Your compressor is getting ready leave this world. I would short-belt it asap, mine still is, and look at a bearing (compressor guts) replace. Mine also started showing early signs in 'defrost' setting. 2 months later the compressor siezed, had to short-belt it to get it to start.