I've got to ask the pros before I let the stealership look at my 01 CLS.

I searched, but didn't find exactly what I was looking for - so here's my ?s:

Symptoms:
A low hum from under the hood, audible inside the cabin, with the car at idle (in drive or park) associated with the AC system.

I know it's the AC system because turning the AC off immediately silences the noise, turning it on immediately brings it back.

I am concerned because I haven't been able to hear that noise inside the cabin before - which makes me believe something in my AC system is tearing up. I know there is some noise associated with a normally functioning AC at idle - but again, I don't remember hearing it before inside the cabin.

Air still blows cold - although, I'm not sure I have ever had the AC serviced with new coolant. If I have, it's been a long time.

Question: Am I paranoid? Is this a noise that I should be able to hear?
Question: Is it more likely the AC clutch or AC compressor? Is there a way to tell the difference (e.g. will the cold air get warmer as a compressor goes bad, but not if the clutch is going bad?)

I've only had one AC failure (on an 84 Vette) and it was a seizure of the pump. Not much gray area on that one.

Finally: if it is an AC clutch or compressor - is there any associated work I should have done at the same time? For instance - I know most people replace the water pump when they have timing belt serviced since - as I understand it - the pump must be removed to access the timing belt anyway.

Any other insights would be welcome. If you've had an AC failure of any kind and can relate what symptoms you noticed (other than being really hot!) I would appreciate it.

 

i think i may have the same problem as you. when the AC kicks in the noise from the compressor is quite loud outside and in the cabin. the air still blows cold but im just concerned about the noise. it seems like something is def. wrong. its not normal. quite loud and noticible. im scared that im going to have to replace the compressor. but hopefully i can just charge the system and put some oil in it. i may get it diagnosed soon but it could be a while since i have a few things to do before this.

 

Sounds like normal Honda AC compressor noise.

 

I completely allow for the fact that I might be a hypochondriac (or whatever the car repair equivalent is) on this matter.

I just remember when it was new - I sat in the cabin with the radio off and it was silent except for the rush of air through the air vents. Of course, I had just traded an 84 Vette for it - which is most certainly NOT silent! So maybe my perception was jaded.

I work with a guy who drives an 01 TL - so maybe I need to sit in his and listen to the noise.

However, I'd still love to hear from anyone who has had an AC failure about the symptoms that proceeded it.

Many thanks.

 

I hope so cause ive always exp this with my car since getting it. People ask me, whats wrong with your AC, its loud, and i just shrug it off saying its normal for this car. It works awesome mind you, the cold air comes out quickly and effectively even as the car sits in direct summer sun light for a whole day.

 

I completely allow for the fact that I might be a hypochondriac (or whatever the car repair equivalent is) on this matter.

I just remember when it was new - I sat in the cabin with the radio off and it was silent except for the rush of air through the air vents. Of course, I had just traded an 84 Vette for it - which is most certainly NOT silent! So maybe my perception was jaded.

I work with a guy who drives an 01 TL - so maybe I need to sit in his and listen to the noise.

However, I'd still love to hear from anyone who has had an AC failure about the symptoms that proceeded it.

Many thanks.

 

Yeah it's loud on mine with no music on. Under the glove box more so. You may try to replace your cabin filters see it it makes a difference.
The 3 CL's I had all were quiet when new & got louder as time/miles went on. My AC is on 95% of the year.

A side note.... the AC system on 6cyl Honda's are very good. I have yet to hear of something failing on a CL/TL/accord within 110k miles.

 

yea but when i bought the car, no way it was this loud. it sounds like its gonna take a crap anytime or blow up, haha. but its quite loud and its making me worried. but at least the air is cold. i may need to recharge and oil it up

 

Unless there's a leak there is no need to "recharge or oil" the system. It's a closed pressure system. Your just going to waste your $. Get a 134 AC gauge set & check the pressures. That's the only way to test the system.
If the noise is really bad look at your belts, or the tensioner.

 

I hadn't thought about the tensioner. Obviously the tensioner and AC pump are separate systems, but when the AC pump is engaged there is increased force on the belt and therefore the tensioner.

The good news is - I took my car into the stealership 3 months ago to get my new transmission and I (foolishly) paid them to do the 60K maintenance at the same time. If my AC clutch, pump or tensioner is crapping out - perhaps I can bully them into fixing it at a discount since their "thorough inspection" didn't identify the problem when they "maintained" the car.

Ditto on one of the above posts, however: it's definitely a louder noise than I remember.

Are there any visual or other clues that a tensioner is about to die? I know that water pumps tend to start dripping coolant just before they fail (at least on GM cars) - will the tensioner start dripping oil/lubricant or show any other visual symptoms before it dies? Is a loud hum associated with tensioner problems - or is it a different noise (clicking?) or no noise at all?

 

there is a H and L dust cap. for the self-charge kits, you are supposed to use one of those to charge the system so you can diy or check yourself about the coolant level. im just not sure ours is not R-134a. its something like HFC-134a, and it says to use genuine honda syn compressor oil. the self-charge kits come with universal oil.

 

How about at 150K? My AC makes this noise intermittently and it bugs the crap out of me. The noise didn't used to be there and as I put more miles on my car it's only getting louder.

 

At 150K miles the bearings in the compressor, blower motor, or blower fan etc, may be going. These are still moving parts & will wear out.

 

134A is 134A they are ALL the same.

The oil depends on what the car takes. Some universal oil covers many different types of compressor oil & may work fine.