A/C Compressor rattle...occasional stalling

[SHObogdan1]

Hi everyone, I posted before regarding idle issues on my 93 ATX and it seems like its probably due to a bad IAC. This past month or so I haven't had the chance to replace it because I've done a lot of body work to repair rust on the car. I finally finished the job so I drove it around for a couple of days and I noticed a loud rattle coming from the serpentine belt area and guessed it might have been the alternator. When I decided to check it out, I opened the hood and the pulley directly below the alternator was wobbling really badly. Also when I turned the A/C on max the car would stall while idling. So is it safe to say that my A/C compressor/clutch is toast? Could it also cause the inconsistent idle I've been experiencing? When the engine is fully warmed up (and the A/C is off) the car runs really well so I don't think I have a vacuum leak anywhere.

-Just to note: the A/C does work and the CEL isn't on so that doesn't help point me in a direction.

 

[rubydist]

it sounds like you may have 2 issues - one is that the a/c compressor may be locked up, and the other is that the bearings may be shot in the a/c clutch pulley.

you will need to pull the belt off to confirm the bearing issue.

with the engine off, if you grab the outboard part of the a/c pulley, you should be able to turn it. that is rotating the a/c compressor. if this does not turn, you have a bad a/c compressor.

 

[SHObogdan1]

Thanks, I will have to do that, hopefully if the weather is decent this weekend I can get the serpentine belt off to examine the A/C pulley (and all the other pulleys I suppose). There also was a constant whining noise coming from the serpentine belt area that's been going on for quite a long time. Hopefully, If I'm lucky, replacing the entire A/C compressor will solve both issues. I guess I'll have to pile that on top of my replacement list along with the IAC and maybe the TPS. LOL it seems like everytime I solve one problem, three new problems appear within days. I appreciate the advice.

 

[Wilbur289]

My guess is that the bearing on the A/C pulley is shot. That whining sound you heard was the bearings frying away. That would also be the wobble you saw when you looked. The good news is that the compressor itself might still be good and you just need to replace the clutch assembly.

The bad news is that you will have to pull the compressor and to do that you have to disconnect lines into it.

To do that you need to get rid of the refrigerant and that can only be done legally at a certified AC shop. If it was retrofitted to the newer r134 refrigerant already, you don't need to retrofit it. (You can easily tell that by looking for the high pressure service port near the radiator cap, if it's about the size of a tire valve, it's r-12. If it's much larger then it's 134a.)

Best bet is to take it to a reputable AC shop and let them do the work, if it needs a retrofit, bite the bullet and get a new parallel flow condenser as the stock ones do not work too well with the new 134a.

In the mean time don't drive it as the belt may burn up when the pulley completely freezes up.

 

[rubydist]

as I recall, you can remove the clutch from the compressor without removing it from the car.

but first, he needs to determine if the compressor still turns, because it sounds from his description that it might not.

 

[Wilbur289]

I think he said the AC was working in his last line of the post.

Yeah you can work on that clutch without pulling the compressor, but from what I'm thinking the bearing is dead from years of exposure to MgCl and if that's the case, then more likely than not, there's damage to other components just waiting to fail...especially if you start moving lines around.

Easier to get rid of the r-12 (if it is charged with that stuff) and do a proper retrofit and that involves pulling the compressor to drain the oil.

Could also put on a shorter belt and bypass the AC clutch altogether.

 

[SHObogdan1]

Thanks everyone. Yeah the A/C does work, I'll try to find a good A/C clutch or even a good used A/C compressor and take it to an A/C shop to get it squared away.

 

[Wilbur289]

Just make sure that you get the denso 10p15f, Shosource has new ones at $350 and you can get rebuilt ones for $100 less. They can handle the high RPMs that our engines put out, anything less will just die. If the compressor is still good, you might be able to have one installed and you might even be able to just replace the bearing if the coil and the plate are still good.

Reason I am commenting on this is that I just finished repairing my AC on my 1992 and it was tough to work on without pulling the compressor and my bearing was still good, just needed to adjust the air gap on the plate and that was **** in itself. Fitting the tools in that are needed to pull the bearing and install a new one would have been even harder.


Maybe you'll get lucky and find a shop with a wiz mechanic that can replace the bearing without adding a lot of extra labor on.

 

[SHObogdan1]

I appreciate the suggestion but $350 is just a bit out of my price range. I just found a good used complete A/C compressor for $30 today at the junkyard. All I have to do now is just find a good repair shop that can get it done for $350-$400 labor and I'll be all set.

 

[SHObogdan1]

I bought the A/C compressor from the parts store and after removing the A/C compressor on my car, I noticed that the two are not the same (although the employee said the compressor was removed from a 1993 Taurus SHO). The one on my car has a snap ring and a nut that holds the pulley onto the clutch hub while the one I purchased has a spline shaft with a bolt that holds the pulley onto the clutch hub. Also, the one I purchased has the A/C ports in a different location than mine. Are the ATX and MTX A/C compressors different? Or are they just different because one uses R-12 freon factory while the other one uses R-134a? I'd like to buy the A/C clutch listed on rockauto but I can't tell from the picture if it has a snap ring on the pulley or not and the description doesn't say anything. I tried to call rockauto for more info on it but they had no idea either. Do you guys know if the A/C clutch listed on rockauto is the right replacement for a 93ATX? Only reason I'm asking is because of the hassle it is ordering the wrong part, returning it, then searching some more another one. Thanks again!

 

[kevinspann]

No, the MTX and ATX use the same 10P15F compressor. Sounds like you have the wrong one, which is common.

 

[SHObogdan1]

Maybe I was sold the wrong part...but even on rockauto the A/C clutch hub looks very different between the ATX and MTX, and the part number and prices are different. From what the pictures show, it kinda looks like the MTX has the spline shaft that holds the pulley to the compressor.

 

[rubydist]

the correct a/c compressor has a snap ring that holds the pulley onto the compressor, and a bolt/nut that holds the outer clutch half onto the pulley, and the clutch half is oriented to the compressor with a keyway.

the one you got sounds like the standard Taurus part, which is completely different.

 

[JRA2000TL]

Get a Nippondenso 10P15F, as stated. Check Ebay and search "10P15F compressor" I paid $110 shipped for mine. 99.9% it's a reman by Four Seasons. That's about your only choice now. It's hard to find a brand new one and you will pay $300+. I could not find a NOS Motorcraft/Ford one. If you go that route, replace the accumulator and the liquid line. Check Ebay for the accumulator. You can get them for $40-50 vs. $100+ from RockAuto and everywhere else. The liquid line will also run you $20 on Ebay. Trust me....Ebay is better for parts in terms of A/C for our cars. I just went through this and replaced my entire a/c system in my 89 (minus the evaporator, which was fine). 38 degrees out of the vents.

 

[SHObogdan1]

Get a Nippondenso 10P15F, as stated. Check Ebay and search "10P15F compressor" I paid $110 shipped for mine. 99.9% it's a reman by Four Seasons. That's about your only choice now. It's hard to find a brand new one and you will pay $300+. I could not find a NOS Motorcraft/Ford one. If you go that route, replace the accumulator and the liquid line. Check Ebay for the accumulator. You can get them for $40-50 vs. $100+ from RockAuto and everywhere else. The liquid line will also run you $20 on Ebay. Trust me....Ebay is better for parts in terms of A/C for our cars. I just went through this and replaced my entire a/c system in my 89 (minus the evaporator, which was fine). 38 degrees out of the vents.

Thanks JRA2000TL! Yeah ebay is alot better than all the other places in terms of prices. $110 definitely beats paying $280+ for what's listed on rockauto. Like you said, since I'm already in the process I'll go ahead and replace the accumulator as well. Once again, I greatly appreciate it!

 

[JRA2000TL]

Thanks JRA2000TL! Yeah ebay is alot better than all the other places in terms of prices. $110 definitely beats paying $280+ for what's listed on rockauto. Like you said, since I'm already in the process I'll go ahead and replace the accumulator as well. Once again, I greatly appreciate it!

No problem. I bought my compressor from an a/c parts distributor (via ebay though, of course). It didn't come with oil already in it, but it came with a bottle of 8oz. PAG46 oil (the specified 134a oil for the compressor). I simply poured that in, rotated it a few times by hand, and bolted it in.

I do recommend, however, taking it to a shop once you install everything and having them pull a good vacuum and recharge on their machine. Since you're replacing the accumulator with the compressor, you want to have the shop vac and re-charge pretty quickly once you do the install so you don't ruin the dessicant in the accumulator. Try not to leave the lines exposed for too long. Leave the lines capped until you're ready to do the install.

Since the correct amount of oil and refrigerant is critical to system performance, that's why I recommend paying the shop for that portion of the job. It'll run you about $100. They will make sure of the correct amount of oil and refrigerant in the system.

As stated, you can remove the clutch from the compressor w/o opening the system, but it's a b**** and a half to do while in the car. In my case, my compressor simply died and my car had 260k on it. I decided to gut everything and replace all of it. A/C is critical where I live. Good luck.

 

[Wilbur289]

The compressor itself may not need replacing at all, you could replace the bearing on the pulley then use the stock compressor once it has been drained of the oil used with the r12 and charged with PAG 46. The system calls for 7-8 FLUID ounces of oil meaning 7.5 should be used total. It calls for 41 FLUID ounces of r12 and that will translate to 34 of r134a.

TBH, this job can't be done properly until ambient temps get to 75+ degrees. I really would urge you to wait until after your winter is done and you are far enough into spring to get some warmer weather to get the job done. Trying to suck out r12 when it's cold is not an easy thing to do. Leaving any r12 and old oil in the system will mean doing it all over again later.

If you really must drive it, put a shorter belt on and bypass the AC pulley. I do not consider this a permanent solution as you will possibly put more stress on the alternator than what is was designed for.

The upside to parking it for the winter is that you won't expose that aging car to the crappy MgCl strewn on the roads there and you will be more certain about exactly what needs to be done.

Once again; you most likely do not need to replace the compressor itself and quite possibly the clutch plate and coil are ok. That bad bearing is what needs to go and that itself will not set you back much.

 

[SHObogdan1]

The compressor itself may not need replacing at all, you could replace the bearing on the pulley then use the stock compressor once it has been drained of the oil used with the r12 and charged with PAG 46. The system calls for 7-8 FLUID ounces of oil meaning 7.5 should be used total. It calls for 41 FLUID ounces of r12 and that will translate to 34 of r134a.

TBH, this job can't be done properly until ambient temps get to 75+ degrees. I really would urge you to wait until after your winter is done and you are far enough into spring to get some warmer weather to get the job done. Trying to suck out r12 when it's cold is not an easy thing to do. Leaving any r12 and old oil in the system will mean doing it all over again later.

If you really must drive it, put a shorter belt on and bypass the AC pulley. I do not consider this a permanent solution as you will possibly put more stress on the alternator than what is was designed for.

The upside to parking it for the winter is that you won't expose that aging car to the crappy MgCl strewn on the roads there and you will be more certain about exactly what needs to be done.

Once again; you most likely do not need to replace the compressor itself and quite possibly the clutch plate and coil are ok. That bad bearing is what needs to go and that itself will not set you back much.

I have to replace the entire compressor; I forgot to mention, when I removed the serpentine belt and alternator, I finally had access to the A/C compressor and noticed that the pulley and clutch hub were cracked and and part of the pulley actually broke off. I couldn't get the snap ring off of the compressor (while attached to the engine) so I unbolted it and tilted it without removing the lines. When I got the snap ring off, I guess I pulled the seal along with it and the freon leaked out. Nonetheless, I took out the compressor and found out that it's remanufactured so the previous owner definitely replaced the original. In addition, the previous owner also did the r134a conversion because the A/C port is larger than the standard r12 port. So, if I were to buy the seal and the A/C clutch, I would actually pay more money than buying the entire A/C compressor for $90 on ebay.

 

[Wilbur289]

... So, if I were to buy the seal and the A/C clutch, I would actually pay more money than buying the entire A/C compressor for $90 on ebay.

Yeah, that reman compressor was probably the at the root of the problem. Hope you have the proper Denso for your car, if not you will have to do it again.

 

[SHObogdan1]

Hope you have the proper Denso for your car...

Yes it is.