W201 A/C not cold enough - PeachParts Mercedes-Benz Forum

73MB280SEL · #1 03-17-2003, 07:29 PM

Howdy,

I have a W201 190d 2.2 that I drive daily back and forth to work. The A/C has been converted by the previous owner to R123. It works pretty well when the sun is not shining or the outside temp is lower than about 80. Now that its getting warmer, I have noticed that the A/C isn't cutting it. Today, when the sun wasn't shining, the A/C blows really cold. But when the sun is shining, (same temperature), the A/C just doesn't come out of the vents very cold at all.

Would this be an indication of not enough condenser: That is, this is a converted system so it doesn't have enough condensor to get the freon liquified? Or would this be an indication that there is something wrong with the system: overcharged, too much air in it, etc...

I just wanted your opinions before I sought advice at my local independent shop.

Thanks,

Sholin

jgl1 · #2 03-18-2003, 12:14 AM

Wasn't that vehicle factory equipped with R-12?

73MB280SEL · #3 03-18-2003, 06:02 AM

Yes, I'm sure it was, but that was 1984. It has been converted--I don't think it is even lawful to recharge a system with R-12 anymore.

Sholin

#4 03-18-2003, 08:33 AM

The loss of capacity when changing to 134 is significant. These cars do not sufficient excess capacity to tolerate this loss of capacity.

Possibly the system is just low on refrigerant causing the degraded performance. If the refrigerant is not low, however, you have two choices; you can add a parallel flow condensor that will help some, or you can completely flush the system, change the filter drier, put in mineral oil and go back to R12.

The conversion from R12 is false economy in most cases. You are only working on the system when there is a problem of some sort. The other expenses of repairing the system always exceed the cost of the R12.

Now that you have converted, you are faced with even more expenses. This is a good example of why not to convert to R134.

Good luck,

73MB280SEL · #5 03-19-2003, 06:02 AM

I agree with you that R12 systems are superior in every way. I've owned only 1 new car ('96 Chevy Z-28). It came with an OEM R134 system that works well under most circumstances, but still would loose capacity and stop cooling when idling on a hot day.

The thing is the converted MB system seems to work well unless the sun is shining. I haven't had anybody check it out yet, but there is (hoping...) maybe just something wrong with the system and not just "the way it is".

The best A/C I've ever had in a car is an '88 Toyota Corolla with a nippondenso compressor and R12. I still have the car and it still has its original R12 charge with no service whatsoever.

Question: Is it LEGAL to convert back to R12. I guess the system originally came with R12, but I was under the impression that you couldn't refill a system with R12. Maybe I'm wrong. Of course one of the guys in the office has a license and can service all sorts of A/Cs, but I still would be concerned if it weren't legal.

Thanks,

Sholin

gregga · #6 03-19-2003, 11:01 AM

The illegality is that you are obligated to repair any and all leaks in the system prior to recharging with R-12. If a shop gets in a leaking system, they are required to recover all R-12 until those repairs are complete. You can't just top off an R-12 system any more. The shop is supposed to pull it down even if you elect not to fix it.

73MB280SEL · #7 03-19-2003, 06:31 PM

Gregga,

Thanks for clarifying that. I have heard that in Canada it is illegal to service an R12 system. I'm glad to hear that you can fix the leaks and restore the system back to R12.

Thanks,

Sholin

#8 03-20-2003, 07:38 AM

Topping off an R12 system being illegal is a MYTH! In the material studied and tested on for a 609 certificate, it makes this very clear. In fact it is ILLEGAL for a shop to tell you this. They are either ignorant of the law, or they are trying to soak you for more repair expense.

That said, it is certainly not WISE to top off any system if there is a significant leak.

If you need verification of what I am saying you can go to any of the sites where you test for 609 and read the material.

Have a great day,

73MB280SEL · #9 03-22-2003, 06:53 AM

I don't think my system is leaking. It cools fine and is not low on refrigerant, but just doesn't have any capacity when the sun is out.

Either way, I doubt that I'd want to get into the habit of topping off an R12 system. That would be more expensive than just fixing the leak in the first place.

Thanks,

Sholin

mpnye · #10 03-22-2003, 01:14 PM

Well . . . That was THEN . . . THIS is NOW ! ! !

If you have a supply of R-12 that was purchased back when it was a BUCK a POUND . . . GO FOR IT ! ! ! Being in some areas, it now goes for 100 BUCKS a POUND . . . R-134A is the ticket.

In the REAL WORLD . . . R-134A WORKS as an SAE and DOT APPROVED refrigerant.

There are a couple of guys a few miles away from here who are doing 10 years for charging systems with Butane. I was one of the FIRST shops in my area to retrofit to R-134A . . . You wouldn't believe the BULL**** that I heard from people who didn't know **** from Shine-ola. There were shops who were just adding R-134A WITHOUT doing ANYTHING ELSE . . . Compressors were locking up INSTANTLY and R-134A was the SOLE BLAME. These were the same IDIOTS who told people NOT to go to my shop as I CEASED using R-12 due to COST and was ONLY retrofitting to R-134A.

I have a retrofitting formula that I've developed from utilizing the BEST retrofitting procedures from various sources. I've been retrofitting for over 11 years with no MAJOR complaints.

73MB280SEL · #11 03-22-2003, 06:57 PM

Howdy,

Here's a link to hydrocarbon refrigerant replacements. It's a grey area as to the legality of using this but the argument for it being legal is as follows: R134A is not classified as an ozone depleating element so the replacement of it is not controlled by the same agency as R12, which is. On the other hand, it's flammable.

hydrocarbon refrigerants

I gotta admit, the idea is attractive. I'm not that worried about flammability. Heck, the car is full of freak'n fuel anyway.

mpnye, do you have any experience with these producs?

Sholin

mpnye · #12 03-22-2003, 07:04 PM

Here's the FACTS . . .

There are ONLY 2 (two) refrigerants R-12 & R-134A that are SAE and MANUFACTURER APPROVED for AUTOMOTIVE AIR CONDITIONING SYSTEMS . . . PERIOD ! ! !

mbshop · #13 03-23-2003, 01:15 AM

some misinformation here. if a change over is done correctly
there should be very little differance. most areas do not require repairs if you have a leak. not in my area in calif. i'm in the central valley that is in the 100's during the summer and don't have any problems with change overs. don't use alternative gasses. most shops will either refuse to work on them or charge a lot of money. i check all cars. if they have alternative gases i charge almost $200.00 more to capture that gas and send it to be destroyed.
the fact that you say that it doesnt cool when you go into the sun makes me think you have a control problem. if you mean when it gets hot then your system needs to be checked.