hey all .. i've read up a bit on these forums to get some ideas about my problem so please can someone help clarify further for me..

When I turn my a/c on.. there's a loud grinding type noise coming from the engine. What is that? How do I figure out if its just a belt issue or the compressor itself?

From what i've gathered.. its likely the compressor if noise happens when a/c is on?

- How can I isolate the cause?
- Is it possible to do a DIY check & fix?

1998 TF Magna

also.. air con was still pushing out cold air while the noise happens. not sure if that is relevant info. but still looking for some advise on this issue guys .. ? please help.

When I turn my a/c on.. there's a loud grinding type noise coming from the engine.


Is the noise short and only happens when you turn the A/C on, or is it there all the time?

If first = normal A/C clutch operation.
If second = worn A/C compressor internal bearing.

If the belt on the A/C is not tensioned right its vibration sounds like a grind/rattle - it's a cheap or easy adjustment if you need to check this with a mechanic

Is the noise short and only happens when you turn the A/C on, or is it there all the time?

If first = normal A/C clutch operation.
If second = worn A/C compressor internal bearing.


Hi MadMax... thanks for replying.. This noise is definitely not normal.. Its never been there before.. noise starts few seconds after I turn the a/c on then stays there until I turn it off again.. so i think its as you said .. worn internal bearing..

- Can I still drive the car around in the mean time without using the a/c ? Im assuming if I don't use the a/c then there's no danger in driving right ?
- Can one do a DIY fix on this ? fix the bearings or buy a replacement compressor and bolt it on ?

I never knew how uncomfortable it is driving around without an a/c lol esp. right now in the middle of summer !

Just had a look on ebay for replacement compressors.. saw some selling for $65 - $100. Looks reasonable.. although I might have a re-gassing issue I suspect.. if i tried replacing this myself ? which is beyond my scope.

Thanks again.

thanks.. but i doubt the belt is causing this now based on what MadMax pointed out..

Could still be the belt, there is no load on it when the A/C is off, turn the A/C on and the belt is given a load, it may be slipping, loose, or hardened with age.

Get a mechanic to listen to it.

If it is an internal component:

Not using the A/C is probably ok, and a smart thing to do. Inner parts of the compressor are not spinning if the A/C is off.

Really needs an expert, a compressor that is shedding metal internally can put a lot of metal through the whole system and it will need cleaning out - just replacing the noisy compressor may not do the trick.
So you will need:
a) To have the system cleaned out, or the original compressor removed to see how much internal damage there is and if metal has been lost from it.
b) Find and fit a good compressor. (an eBay s/h one is risky, see following steps.)
c) Replace receiver/dryer.
d) Vacuum down system, check for leaks.
e) Gas up system with refrigerant, oil, dye.
f) Test for leaks, check for performance.

If your eBay compressor is not good, go back to step b.

Costs add up.

I've seen people drive around in the 40 degree weather, in late model cars, with the windows down.
Either they are used to the heat and like it, or their A/C is stuffed and they consider it too costly to fix.

Maybe take it to a Auto Electrician or mechanic ....... just a thought.

so this magna is a spare car that we have and use on occasion when needed.. or when we need extra space for family trips.. which is why i dont bother too much about costly repairs .. when it dies.. il just get rid of it.. but having said that.. i love the car.. its always been an old fav..

back to the issue.. so air con sat idle all year since my last post.. never used it.. now that its getting hotter.. i turned it on just to see if the noise was there.. and guess what... nothing!... noise gone.. cold air blowing through like before.. its as if nothing happened.. so ive been driving around a little paranoid with the air con on and window down .. no noise.. parked at home.. air con on .. no noise.. no rattle.. no grind..

any thoughts on that ? how can sth that sounded so serious earlier this year be gone now ? should i be worried at all ?

Sorry to sidetrack for a moment, but I'm also having an A/C issue. I need a new compressor (total cost for compressor/filters/regass is upwards of $1000 for a car hardly worth that much), so I'm looking at getting a 2nd hand on for a fraction (risky, I know), so just wondering if anyone knows if a 1998/99 compressor would fit in a 2002 TJ Series 2? As far as I know the Magna didn't change much mechanically in that period?

I had a very similar sound to my TW. Like BB21266 said, Turned out to be the belt, compressor was in perfect condition.