TresX

Yes the compressor seems to be engaging. The lowest I've seen mine was at 7 bar. So your answer I guess is 7, but when you turn the car on and activate the system, it fluctuates.

The ML....if you were getting HOT air before and are getting cooler air now, maybe you just need more refrigerant. As soon as you refilled it, was it ever really cold? If not, is the temp of the air the same after you refilled it and now? IE has it gotten warmer? If not, it's not uncommon to underfill a system that needed recharging. (Thing is, you shouldn't be leaking refrigerant in the first place). You just need the cabling and guages to check. If you do need more, just make sure you use a can with UV dye in it.

ThrillKill

ML is not that bad after I had it recharged but still not like it used to be. I've never changed the cabin filter so I have a feeling that might be it.

DevilsAngel

Ya thats originally what my mechanic said. I was just hoping that it might not be that and be a cheaper fix. He said it would be about $200 to fix UNLESS it was a leak more inside and they had to take out the dash...does that sound more like the leak that would cost $800-$1000?

I didn't use the uv dye, looked at it when i was at the store, but didn't get it. is #7 the refrigerant level? cuz when i first recharged it was at a 5 and when i checked it today it was at 2.
And one more, if I here the compressor engaging does that mean it still might be bad?

p.s. really appreciate the help. there's so much to learn about my car

TresX

yes 7 if refrig. level....$200 fix? I would be very careful that he doesn't add any kind of sealant type chemical into your system. TRUST ME....you will end up paying THOUSANDS if you go this route. Get it fixed properly. I don't know of anything that can cause a refrigerant leak that would cost $200 to repair. Your compressor is engaging so it's not "seized", which is a common failure, but it can still be bad. (Busted gaskets --> leaking refrigerant) Even a rebuilt one costs 600 easy. Taking the dash apart will cost you about $1k in labor ALONE. Then you have to pay for whatever is broken and the labor to replace that as well. You DON'T want to take your dash apart!

TresX

P.S. Whatever needs replacing...make sure you go to a reputable shop....it makes the world of difference. Some may not evacuate the system and/or even not replace the dryer.

DevilsAngel

oh ya understand with going to reputable shop, my bf made that mistake with his audi. took it to a shop that was closer instead of where i will only take my car and got charged for something that wasn't even wrong with the car. so i vowed to not go anywhere else but http://www.matrixintegrated.cc/ in Portland. Its an awesome shop. one of the mechanics have a stage 3 s4 that runs 11's i believe. its freaking sick. the owner has a sick E55.

so i guess pretty much case closed, its just time to take her into the shop. it was worth a shot. lets just pray it stays cheap

The Jury

Yesterday I was having problems keeping my interior cooled off. The Ac didn't seem to want to go into full blast to help me out. I usually keep it at 72 degrees and it's cold inside, but I was all the way to 68 yesterday and it wasn't getting any cooler.

Today I started it from sitting all night, it blew ice cold for the 3 minutes I had it running. I took these pictures after 3 minutes of idling in a garage with the exhaust going out the open door, but the front enclosed in the garage and building up heat under the hood.

I need to find out what the deal is because it is in the 90's here as of this week. I don't want the AC randomly working.

The Jury

Perhaps a better question is where are the internal temp sensor(s) at? I clean my car religiously and I might have gotten some cleaner in it.

TresX

Your evaporator temperature sensor is bad.....it's located above the driver's footwell along the firewall. Your car is showing a value of 118 degrees for that sensor when inside the car it seems to be 81 degree and outside the car it's only 99 degrees. Change it and I bet you will get cold air all the time.

hijacker(GR)

Two weeks ago i had the same problem,hot air and a/c lights always on!
Went to a local MB service and in 1hour the car was ready,he said he changed some kind of relay.I paid only 30euros here.
Sry for my bad English

viguera

Any ideas on what the evap sensor looks like? Any pictures from anybody that has seen it? I understand that the part you can order from the superstore is different from the part in the car.

After changing my driver's seat motor I've been endowed with newfound confidence that I can probably do this myself... and although that's probably a mistake, at least I'd like to try and see...

Hell, even if I can't figure it out I'm just out $50 and I'll take the car to the dealer. But I'd rather try to do this myself first and see how far I can get.

s4play

I just found this thread on a search but my problem is the reverse.....

NO HEATER! My A/C blows nice and cold but I have no heat whether I have the dial turned to hot or cold on my 99 ML320.

any ideas on this problem? My Mechanic says the ML temp controls are all electronic so he recommends I replace that entire 3 dial control unit.


rick