Just when things are going well for a while...

[formula_gramps]

Happy summer everyone. Haven't been here in a while, but I just acquired a new problem with my 94 Formula.

Last year I did a lot work to fix some rough running and hesitation problems my 'Bird was having, and managed to get the old girl running beautifully. In large part due to great advice I found here on this board. Thanks for being such a great forum!

All was well until May this year when some chowder-head hot-footed it out of a parking lot, while looking back over his shoulder for oncoming traffic, instead of in the direction his car was going, and drove into me head on. There was enough damage that it would have exceeded the threshold for considering it a total loss, but thanks to some arm twisting of the body shop guys and the appraiser, I got them to back out enough of the mechanical repairs to keep the number just below the "total" trigger. I figured I could handle the mechanical repairs myself. Minor stuff really except for the brake line which runs from the proportioning valve to the rear axle.....that was fun. It had been corroded anyway and when I hit the brake pedal in the accident, in an attempt to push it through the floor, the line burst. Didn't matter anyway, since I was actually using the other guy's car for brakes.....LOL.

Anyway, after getting all the body work done I decided to have the rest of the car repainted as well. My black 'bird looks nearly as good now as when she was new. Getting some of the parts for the body shop was quite an odyssey though, and the car was tied up for a whole month.

Life has been too easy since my Formula was fixed so I guess it was time for a new problem:

Today, when I started it up it suddenly made a nasty "grinding bearing" noise. I think it's a belt driven component, and I tried to use the stethoscope but I can't say for sure which device it is. All the components sound loud through that thing! I am suspecting the compressor though. There is a variation in the travel of the pulley that is so tiny, but I can even see it with these old eyes, and the sound changes whenever the clutch engages. Tried a little WD around the shaft but that didn't change anything.....(didn't really think it would....).

Tommorrow I'll get it up on the ramps an yank the serpentine off. I should still be able to start it up and run it for a few seconds with no harm, right? If the noise goes away, I'll know it's definitely one of the belt driven devices. While the belt is off, I can work the pullies by hand to check for noise or slop.

Does this sound like a reasonable way to diagnose the problem? Any other ideas will be greatfully considered.

If it turns out to be the compressor, I know I'll have a few more questions, so I hope you folks won't mind.

Thanks in advance.

[MN6WS6]

Mine had a similar noise, and it turned out to be the auto tensioner pulley. You can replace just the pulley to save some money. I know what you mean about using the stethoscope method. I put the car on ramps and physically got underneath the car and listened by ear. I had already had the AC compressor replaced, so that pretty much eliminated that. It was coming from right around that area, so that narrowed it down for me pretty simply.

[BrdWAtti2d]

You should be able to start the car without the belt attached. Since the water pump is not belt driven, no harm, no foul. Naturally the battery will not be recharging and the power steering and a/c will not function, but you obviously already know that. So running it for any length of time will run the battery down. Good call by MN6WS6, my tensioner pulley went south as well and made a horrible racket. It was very obvious once the belt was off, the pulley was very sloppy.

The problem could also be in the a/c clutch, negating the need to replace the whole compressor. If the noise is coming from the compressor and does not stop with the a/c off there's a good chance it's just the clutch.

[MDMike]

Glad you were not hurt.

[formula_gramps]

O.K.....

Some days delayed attending to this problem due to previously scheduled vacation, but now I'm back on it.

First off, thanks to everyone for their suggestions, and to Mike for the kind words. I wasn't really hurt in the crash...unless you count my wallet

I suppose you have to look on the bright side of every piece of bad luck. With the serpentine off, the noise is predictably gone. So no internal engine problems...whew!

I can spin the alternator, and tensioner pretty fast by hand with no noise and no sign of bearing slop. Ditto the power steering pump, although it's not as easy to spin as the alt. But I think that would be normal.

As for the compressor and clutch. I can turn them by hand but it takes a lot of torque to move them. I can just about turn them with one hand. The clutch still turns independently of the compressor, but it seems very hard to turn. To me, that doesn't seem logical. Harder still, is the turning of the compressor, but I don't really know what it's supposed to feel like. No bearing "slop" in either that I can see or feel.

Interestingly, the A/C still seems to work fine. Good stream of cool air, and the clutch engages and disengages periodically as you'd expect. It just makes the most God-awful noise, clutched or unclutched, and I'm afraid to drive it right now for fear it might just seize up.

I've considered eliminating the compressor with an A/C delete pulley setup, block the two lines and just go without A/C. I rarely use the A/C anyway. Up here in New England when the weather is nice, I like to pull the t-tops off anyway. But nagging at me is the fact that I read somewhere that if I do that, my windsheild defroster will no longer work. Does anyone know if that's true? Having no defroster is not an option up here!

Also, just to disconnect the hoses to the compressor would mean that I have to de-pressurize the system... right? Is there any safe way for the DIY'er to do that? This system uses R134 so it would not be like dumping freon into the atmosphere. ( I certainly don't want Al Gore coming after me....LOL).

After reading Joe's thread about how much he hates working on AC systems, I'm somewhat apprehensive, since I'm sure my mechanical skills are a fraction of his.... I've done a lot of repairs over many years...just never worked on an A/C system.

Your suggestions on how to proceed would be very much appreciated.

[Trash man]

it's not as easy to spin as the alt

alternators should free spin when not hooked up to a power source

the clutch should spin hard due to the fact that is what makes the a/c compressor work(without gettin too much into detail, picture mini engine), the pully should freewheel also when its not engaged

[formula_gramps]

Thanks Kyle,

Roger that, on the internals of the compressor, I understand that's why it would be hard to turn. But something you said may be the key to this problem, I just want to make sure you and I are talking about the same things. In the picture below (only one I could find quickly), I have the two items labeled "A" and "B".

My understanding is that "a" is the clutch. Am I to understand from your description that this portion is always connected to the "guts" or internals of the compressor, and therefore would be hard to turn by hand? Do I have that right?


Further, are you saying the portion marked "B" is supposed to be just a free-wheeling pulley that should turn quite easily by hand? Because it doesn't. It's very hard to turn. Is this just a pulley on bearings that has no connection to the internals of the compressor? If so, it must be the bearings that are trashed.

Have I interpreted this correctly?

Thanks again!

[MN6WS6]

Yep, A is the clutch which is always connected to the guts, and B is the free-spinning pulley, which also has a surface on it for the clutch to engage onto. If B is hard to turn, B is your problem.

But.

I've never pulled apart a compressor, so I don't know that you can replace just those bearings. If you want my opinion, I would replace the whole compressor, but you are talking about big bucks. The reason I say that is that once one part starts going out, it's just a matter of time on the rest of it. The clutch went out on my compressor, and I had originally planned on buying just the clutch, but the technician at my work got the car in the air and also noticed it was leaking oil out of the front, so I got a compressor instead.

If you replace the compressor, you also need to replace the drier and expansion valve, and you might as well go ahead and put a low side pressure switch, which is located on the hard line, while you are doing all of that. The drier, expansion valve, and switch are fairly inexpensive, but the compressor is probably $500 from the dealer, and I HIGHLY recommend you put a Delco/GM/Delphi compressor on it as aftermarket ones just don't measure up. And the dealer is going to charge you out the ying-yang for that work. So my suggestion would be to shop online for the compressor or use Dal Slabaugh (sp) or Jason Kromer (sp) at the two dealers that give f-body owners employee pricing. At least you can save some money on the parts.

BTW, if you bypass the compressor, you will lose the defroster. The defroster uses the compressor to take the humidity out of the air so that it blows dry, hot air on the windshield so that it doesn't fog up on the inside.

[formula_gramps]

Thanks MN.....that makes a lot of sense.

Actually, I think the bearings are available. I believe that they are available through RockAuto. If I remember right they're around 20 bucks. Certainly worth a try. Beats discharging the system, replacing the compressor (like you said...big bucks), vacuuming the system out, recharging, etc.

Based on what you told me about the defrost, I would have to have a working compressor even for the winter. Can't live up here in cold, dreary, damp, New England without a defroster!

The only thing I'm wondering is where I can get the special tool for pulling the clutch off. Looks like it would have to be some sort of thread-in deal, but I've never seen one. It would have to be pretty darn small too, to be able to pull that sucker off with the compressor still in place.....hmmmmmm.

Like you, I've never pulled one of these apart. Heck, I didn't even know which part was actually connected to the guts 'til you straightened me out.....LOL.

Thanks for the good advice, and if anyone knows where I can get that clutch removal tool, please let me know. Already checked with the local AutoZone, but they don't have it. In a way that's good. They'd probably give me the wrong tool anyway. Those people scare me. Most of them know very little about cars. Generally, you're talking to someone who was selling hemorrhoid cream at WalGreens just weeks ago.

All the best,

Gramps