Air conditioner noise

[blackrodeo]

How often does your a/c compressor cycle on and off and how much noise does it make?

Mine makes a big thunk when it cycles on and off and seems to do it often (as compared to my other vehicle which I was driving today)?

I'm just trying to figure out if it is normal or on its way out.

Thanks!

[tonnydoodles]

check the freon level, it might be low

[Nathan08T]

The cycling on off (like the person above me) is called short cycling and is mostly caused by a low refrigerant level.

What kind of noise does it make? I've seen lots of compressors make strange noises when starting up, majority of them never have any problems. Mine, however, makes a thud/grinding noise.. I was told the clutch and/or bearings are about to go bad.

[Rhanagar]

I hope it hasn't got Freon in it ... should be R134a which is a Hydro Fluoro-Carbon.

The thunk is either low refrigerant or low oil ... Have you had a leak check done on it?

Nathan your problem sounds like the bearing gone in the pulley wheel. If you take the belt off and undo the screw in the middle of the clutch plate you can get a peller onto the front plate and it comes off. Behind that is sometimes a circlip which then needs removing. Then the pulley wheel can be pulled off. The pully wheel is an interferance fit with a bearing in the moddle. When mine started making grinding noises it was the pulley wheel at fault and when I removed it I had loads of ball bearings sat on my driveway along with shredded bearing races. I just dumped the system cpompletely and fitted plain pulley in place of the compressor. You should also have your refrigerant level checked and checked for leaks. New worldwide legislation has just kicked in for refrigeration so it will pay you both to get it looked at.

As an aside if the refrigerant is gone from your system the oil in the compressor cannot get around to lubricate the compressor innards. This will lead to eventual siezing of the unit (much like an engine without oil). I don't have to tell you what would happen if that happened at 65 on the highway.

Front bit of a compressor broken down:





In the first photo you can see the giant magnet still attached to the compressor, then the pulley underneath it with the bearing in the middle. In the second photo I am holding the clutch. The inner and outer rings are held on with the plates going outwards. The magnet energises when the A/C is switched on and pulls the rings onto the pulley. As the pulley is turning with the engine once the clutch is engaged the pulley will then turn the clutch and inturn the compressor.

It is recommended to run your A/C at least once a week for 10 mins to ensure you keep the oil and refrigerant inside the system moving around lubricating everthing to prevent things from siezing.

[nepato]

Ive had the buzzing sound and small thunk when the ac kicks on since i bought my rodeo 3 years ago. It still blows ice cold though, but i probably should get it checked out soon.

[robs]

The thunk could be a liquid slug sitting in the compressor. Basically as the unit cools any oil and/or liquid coolant makes it way down into the compressor since it sits lower than anything else in the system. Air compressors don't compress liquid just kind of push them out. I wouldn't worry about

Mine is very excessive when I park overnight in my driveway at a decline. Parking at incline or level and I don't have this issue.

[twilson]

Mine, however, makes a thud/grinding noise.. I was told the clutch and/or bearings are about to go bad.

***FYI**

I would reccomend bypassing that compressor with a shorter belt, as soon as them berrings blow the compressor is going to stop spinning, then the belt wont move, its going to tear your belt off.... It literally almost happened to me.

-I no longer have AC but its bypassed as of now.

[DanielHerbert77]

Hey there,

I have a '99 Rodeo (V6, 3.2L 4wd, Auto, LS) with what I believe to be a bad A/C Compressor Bearing. A mechanic told me this nearly a year ago and I thought nothing of it because I didn't notice anything. A few months ago, I noticed a ringing/rattling sound occurring at higher RPMs (around 3500-4000). Around the same time, I noticed an awkward/weird sound - rattling and very noisy while idling also. This noise, along with my valve lifter tick, and fans and belts being generally noisy has led to a terrible sounding truck. Very recently, I have noticed that when the compressor kicks on, there is a horrible whirring noise, especially while stopped at a light or somewhere while the transmission is still in Drive. As soon as I put it in Park, the noise seems to disappear immediately.

Now that the hotter months are going away (NE U.S.) I am thinking of bypassing the compressor altogether and getting the proper shorter belt (don't know which one?). If I replace the compressor, what else should also be replaced, how cheap can I get it, and what should I expect to pay to get it done? I have a few mechanics around me that I trust not to rip me off (I think). I am very mechanically inclined and have done a handful of repairs myself, I just don't have the time or energy right now to perform the work myself. Is it safe to get a replacement compressor from eBay? Is there a source for parts like this within PlanetIsuzoo?

What would you recommend?

[twilson]

To by pass the belt get a 99 Roedo belt w/o AC. very easy to install, you just have to adjust the tensioner bar. Also there is a user on here who may be able to help you get a compressor @ a good price, but do not quote me on that, most likely he can help you tho. If you PM (private message) user "Jlemond"
and ask him, he will be able to point you in the best direction. If you go up to top of screen you will see messages ( 0 new messages) click that then click on new PM, then you will see a link for "find a member" after clicking that you can send different users a PM.

See this post on a diagramm of the engine so you can draw how your serpentine belt goes on.

viewtopic.php?p=241539

and see this post about other people bypassing there AC. I did it my self for a 3.5 l i used a belt off a 99 rodeo w/o AC so i know they have them for you.
viewtopic.php?f=4&t=53346&hilit=+compressor

[tonnydoodles]

I hope it hasn't got Freon in it ... should be R134a which is a Hydro Fluoro-Carbon.

The thunk is either low refrigerant or low oil ... Have you had a leak check done on it?

Nathan your problem sounds like the bearing gone in the pulley wheel. If you take the belt off and undo the screw in the middle of the clutch plate you can get a peller onto the front plate and it comes off. Behind that is sometimes a circlip which then needs removing. Then the pulley wheel can be pulled off. The pully wheel is an interferance fit with a bearing in the moddle. When mine started making grinding noises it was the pulley wheel at fault and when I removed it I had loads of ball bearings sat on my driveway along with shredded bearing races. I just dumped the system cpompletely and fitted plain pulley in place of the compressor. You should also have your refrigerant level checked and checked for leaks. New worldwide legislation has just kicked in for refrigeration so it will pay you both to get it looked at.

As an aside if the refrigerant is gone from your system the oil in the compressor cannot get around to lubricate the compressor innards. This will lead to eventual siezing of the unit (much like an engine without oil). I don't have to tell you what would happen if that happened at 65 on the highway.

Front bit of a compressor broken down:





In the first photo you can see the giant magnet still attached to the compressor, then the pulley underneath it with the bearing in the middle. In the second photo I am holding the clutch. The inner and outer rings are held on with the plates going outwards. The magnet energises when the A/C is switched on and pulls the rings onto the pulley. As the pulley is turning with the engine once the clutch is engaged the pulley will then turn the clutch and inturn the compressor.

It is recommended to run your A/C at least once a week for 10 mins to ensure you keep the oil and refrigerant inside the system moving around lubricating everthing to prevent things from siezing.

freon is the dupont trademark name, lots of people call all kinds of refrigerants freon, and the freon made by dupont is hydro fluoro carbon based.

[DanielHerbert77]

Thanks "twilson" - I have already ordered a shorter belt from the info you gave me on eBay... I hope that works well for now... I will be looking for a more permanent solution so I'm in the market for an INEXPENSIVE compressor replacement also.. THANKS again!

[DanielHerbert77]

Changed the serpentine belt to a shorter one, bypassing the A/C compressor.
Most of the engine noise is gone, except for the worst ringing noise which now seems to be coming from underneath the truck well behind the motor.
It occurs at higher RPMs (3200-4000) and can every once in a while hear it while idling.
Maybe something in the drivetrain?
It's been happening for 3-4 months now and is slowly but surely getting worse, I think?

Any ideas???

[jpj556]

I saw the pretty pictures of the shiny clean A/C compressor and it made me wonder, "Can replace these $17.99 bearings without removing the d*#med thing from the truck? That would save me the trouble and expense of recharging the system!"

Any chance of this working?