mesrop1991

When I put my A/C on, it will cycle on 'on and off' every 5-10 seconds.

During the 'on' cycle, the RPM's drop about 700 RPM's (so if im driving at 3000, it will drop to about 2300). Then when it cycles off, the car regains its power. So the car looses power for 5-10 seconds every 20 second 'on off' cycle.

It makes it impossible to drive with the A/C on.

The mechanic suggested he replace the clutch? Is this accurate?

Help!!

Here is a diagram to point out any parts I may need:
http://www.hondaautomotiveparts.com/...R+%28SANDEN%29

DELuth

The ac clutch? Probably not. What are the pressures? Does the small fan work? The system could be overcharged, clogged, compressor itself could be going out, hard to say without some pressures to go by. It sounds like a serious over-pressure problem, probably overcharged or charged with something other than R134a. The ac comes on, pressures skyrocket, ac pressure switch shuts it down, pressures equalize, ac comes back on, it's called short-cycling. Your ac shouldn't be cycling that fast. Without an ac machine or gauges, there isn't much you can do. But the clutch? It would give problems constantly.

Is there any noise? Does the ac cool normally?

98jdmb16a

Ac is probably over charged just had that problem with my car today but mine would lower 300 rpm. Once I took some freon out of it started working smoothly.

sleepyaccord96

i had the same situation and have seen this alot...

A/c compressor needs to be replaced.

strategy400

Make sure it's not overcharged. If it's overcharged liquid refrigerant will enter the compressor and liquid is very hard to compress. This will damage the compressor.

jayupark

i overcharged mine two days ago. bled it down too much though. now shes warm and smooth again...

rickkane

^^^ This.

mesrop1991

Ok, sorry I took so long to respond! I finally got my a/c belt on, connected a manifold gauge to it and here are my readings.

LOW SIDE - clutch engaged: 90 to 100 psi ; clutch disengaged: 70psi
HIGH SIDE - clutch engaged 100psi ; clutch disengaged 75psi

Bad right?

Also, I wasnt driving when testing, and the RPMS, actually were not lowering when the a/c cycled. Maybe because it was about 60degrees out (not warm). But with the a/c on, it did lower to about 42 degrees.



Conclusion: I should discharge the a/c quite a bit, right?

strategy400

You need to rev the engine to 1500 to take accurate readings.
Still it appears your compressor isn't compressing (similar high and low readings).
@ 60 degrees the static (non running) pressures seem a little high maybe 10 PSI, but this depends on your system.
Higher ambient temps will raise the internal pressure and the load on the compressor.
Make sure your doors are open and fan set on high (not on recirculate) when taking readings.
I'd replace the compressor, condenser and receiver/dryer.

mesrop1991

OKAY

I wont be offended if you call me stupid...


So first of all I was using my manifold incorectly. I did not know the manifld valves were supposed to be closed when reading for high and low preasure. So my original readings were incorect.

ANYHOW...I got the entire system proporly discharged at the mechanics, pulled a vaccum myself, and charged the system with 2 cans of r134a. Now my car gets as cold as 50 degrees.

So i guess the system was indeed overchagred (though I dont know how much because I wasnt using the guages proporly) and put a lot of preasure on the compressor which caused the engine to drop RPM's when the clutch was engaged.

So now that its not overchangred, the a/c is working without putting much train on the engine at all! Good, but hopefully I did not do damage to the compressor by having it overcharged for so long!!

DELuth

I was wondering how in the hell you came up with those weird pressures, makes sense now.

Aaaaannd it's still overcharged. 2 cans = too much. Freon capacity is measured in weight, not cans.

Proper charge for 98 civic is around 1.4 lbs. You put 2 lbs in. Temps should get down to around 40 and start to cycle on a normal system. Too much refrigerant is worse than not enough.

My advice would be to get it charged by someone that has the proper equipment. Since that isn't going to happen, I suggest letting out about half a can. How will you know when you have let out .6 lb? You won't. That's why it is impossible to properly charge a system without a scale.

edit: I just reread that. Did you go to a shop and pay to have it recovered? Why didn't you let them gas it back up? This makes no sense. Labor would be the same and you shouldn't have to pay for refrigerant since they would be putting back less than they recovered.

b20bFourDoorCivicLX

i had the same problem, my mechanic ended up re-charging it with a lower pressure now it works alot better but when i turn the a/c off.....i repeat only off it drops pretty ******* low....i have a crv compressor with a sohc condenser....i swear before when i had it charged to high it was shooting out air or somthing weird car didnt want to stay on.....now it works better but my only problem is when i turn the a/c off it drops down low! would a dohc condenser help my issue

b20bFourDoorCivicLX

i released some of the freon out of the nipples both nipples for a few seconds eeach. its already been charged with a low psi but i just wanted to release a little bit more. to be on the safe side.but it works good im able to drive fine

does having tinted windows help keep car cool with a.c on?

looking to tint my windows asap i have bare glass all over

mesrop1991

I had it discharged, then I pulled a vacuum, and charged it through the manifold gauge.

Cant I tell if there's the correct amount of r134 by the high and low pressure readings?

Regardless, it works perfectly now. Gets temp down to 45 degrees.

JJT211

Yes the pressures can give you a general indication as to the amount of R134 in your system, but it's not exact. As mentioned previously, the proper way to charge your AC is by weight. The best way i've found is to use a cheap digital scale (got mine at Harbor Freight for $10). Weigh the can before you start charging, charge your system and weigh the can as you go. Whatever weight you lose from the can, is the amount of R134 you just charged your system with.



If I recall correctly, the AC system's capacity is about 22 ounces (there's a sticker on the underside of the hood that has that info). R134a normally comes in 12 oz cans. So if you used 2 cans, obviously thats 24 ozs. So its probably slightly overcharged although probably not as much as before.

Don't guess, use a scale.

Bottom line, if it works, I wouldn't worry about it. Dont fix what aint broken

sleepyaccord96

i say bad compressor...you low side should be low and high should be high.(no i do not have actual pressures or exact numbers)

But when the low and high side are close in numbers you have a weak compressor.

chuckie81

Please help, ac not cooling, on 77 degree day, gauges reading 42 low, 155 high. Entire system has been replaced one piece at a time. Ready to give up & sell the car. What am I missing? Thanks

mesrop1991

Well, I did loose some out of each of the two cans. Out of two cans, im sure I lost at least 2 out of 24 oz. And yes, it works, so Im not complaining. Ill take your advice for next time!

Thanks

mesrop1991

Read the whole thread. I was using the manifold gauge incorrectly. Those numbers are irrelevant.

JJT211

Its possible one of your new parts is bad out of box....

Have you recorded the pressures each time you added a new part?