2002 s40 I've had this car 3 weeks now, the AC blowed hot when I got the car, Got one those kits at Walfart charged the system until it was in the correct range. Here is the deal the faster I drive, the colder it gets, the slower, the hotter, if I idle very long it gets hot, if I drive fast for a long while, it will stay cold when driving slow and at idle for a while. any thoughts?

 

Sounds like it still has a low charge. Have you looked at the sight glass on the receiver/drier? On the right side below and behind the headlight there is a small aluminum cylinder with piping running into/out of the top. Also on top is a small round piece of glass (might be dirty). Get a nice bright light, clean the glass, and turn on your A/C. If the charge is very low you will see big bubbles passing by the glass. Slightly low and you will see small bubbles. Full and you will see NO bubbles.

You got bubbles?

Also check your condenser fan. This is the 2nd fan up front that should turn on when the A/C is turned on. Makes a high pitched and very noticeable noise that coincides with your switching on the A/C.

 

Thank you Sir, I will check that in the morning.

 

I turned the ac on today and as usual it was cold and then warm, and then this time the engine temp went way up to right at the bottom of the red area, lucky it was raining and the faster I would drive the cooler the engine would be. when I got home the blower fan ran for a half hour. about two hour later I checked the coolant level, it was about three inches from the top which seemed normal to me.

any thoughts on what could have caused this?

This Volvo is testing my nerves. This s40 has given me more trouble in one month than all of the other Volvos I ever owned put together.

 

A slow opening thermostat? You should get a check engine light with this one.

A bad temp sensor? This usually also triggers a check engine light. You can verify the actual temp with a digital thermometer.

Any coolant on the ground in the morning?

 

That same evening, "last night" I turned on the ac and in a few minutes the temp went way up , I shut off the ac off, Praise God I was turning into my driveway, I stopped, I heard a loud popping noise and then coolant started running out from under the car. the temp gage read normal temp after that. I guess I start checking the hoses, radiator etc.

 

The hose assembly on the top left by the drive belt had popped loose so I put it back together and tapped it hoping to make it to the parts house to get another one. I let it idle for 20 minutes everything ran smooth, I left the coolant cap off to see if there was any movement of the water after about 15 minutes the water started boiling, I put the cap back on, the idled about another 1o minutes. I felt safe to drive. I drove about 1 mile and the temp gage went to red, I stopped and let it cool down a bit, it took a whole gallon of water, I started it back up and it stayed in the red all the way back home. WHAT IS WRONG WITH THIS CAR?

 

Sorry Buddy, to answer your questions.

I do have a check engine light, I will have to get a digital thermometer, and no coolant on the ground in the morning. Actually until I turned on the ac I never had any problems with the engine temp.

 

Looks Like I fixed it for now. I found the answer here of all places: https://volvoforums.com/forum/volvo-...e-34969/page2/ . The fan lately had been blowing long after the car was shut off so I looked that up and found this thread, and wala there was my answer. I'm still wondering what the ac had to do with the thermostat, because before I turned on the air, the engine temp was fine. I drove this car for weeks before I put freon in it and no engine temp problems. Also I had my wife pick up the thermostat for me, and the parts house didn't send it with a gasket, what did they think I was going to do use the old one?

 

I decided to get to the bottom of this ac problem today. You get in the car, turn on the ac, it cools for about 5 minutes and then gets warm. I turn off the ac, wait about 5 minutes, turn the ac back on, it cools for about 5 minutes, gets warm. I believe someone here said low freon, I checked that, actually had too much freon, tooth fairy fixed that for me. I figured out what was happening, the ac compressor kicks on when you turn on the ac and after about 5 minutes it kicks out and doesn't kick back in unless you turn off the ac for a while. Any thoughts on what would cause this to happen?

 

I've not heard of this on the older S40s, only the newer 2004.5+, deshimming. It happened on my 2005 and I fixed it in a few minutes. Volvo AC Pump Shim

Before taking the compressor apart you should check the gap on the clutch. Also, if you have the cash, pick up a set of cheap A/C manifold gages at Harbor Freight. You can then look at working pressures to see what it going on without looking at bubbles and guessing. (Like me )

 

I'm starting to think that might be the problem, it's been a little cooler here lately 78-84 and the ac runs fine, but when it got back up into the 90's same problem.

 

To start off, there is NO freon, it's called R134A Refrigerant for cars 1993 and newer.

Second make sure that you put coolant in the radiator if it was empty then in the reservoir then check to make sure that the hoses are clamped on tight enough due to the pressures. The reason it is pressurized is to keep the coolant from boiling during operations(DO NOT REMOVE THE RESERVOIR CAP IF THE ENGINE IS STILL HOT!). I HIGHLY recommend the you use premixed coolant or use DISTILLED water with another jug of pure non-diluted coolant to do a mixture. TAP water is NOT recommended due to the minerals in it that can cause corrosion within the engine and radiator.

For AC systems, it is not recommended to use a "quick fix in a bottle" or "band-aid" it, unless its a very slow leak (let the pros do the work safely). Make sure that you have good seals on your hoses; the condenser fins are free from damage or dents to allow proper air flow. The Evaporator Should also be clean from any residue in order to give you the "cold air". Engine RPM can vary on how quick and cold it gets but regardless it should be cold "enough" when moving or idling at a stop.

Here is a Video on how a basic car AC system works.


Hope this helps!

 

The ac works fine now that it's 80-85 outside, that's why I think that the ac clutch is overheating.