87 300D Ac blowin hot, smell freon inside car - PeachParts Mercedes-Benz Forum

a2t · #1 08-04-2009, 12:02 PM

A/c on my 87 300D is blowing hot now. I could smell the Freon inside the car for past 2 weeks and now the site glass is all bubbles so I guess its all leaked out. Is there a pretty common place to look when you can really smell the Freon inside the car? The smell would be especially prevalent after it had been sitting for a while and right when your 1st started it up. I examined the lines coming off the compressor, they seem dry all the way to firewall. The leak must be near the air intake because you smell it inside the cabin.

Any suggestions are appreciated. Its hot here!

rrgrassi · #2 08-04-2009, 12:15 PM

Sounds like an evaporator core leak. Could be a connecting line inside the car...you will need a freon sniffer like Larry Bible has to be sure. This sounds like a trip to an indy.

zeke · #3 08-04-2009, 01:13 PM

oof, and an expensive one if it is the core. Hopefully it is the connections at the expansion valve!

good luck

#4 08-04-2009, 01:23 PM

If it's the expansion valve or a connection on same, I doubt that you would smell it in the cabin, BUT you never know for sure. The expansion valve is in the engine compartment on the passenger side firewall, next to the windshield wiper box.

You could charge it and put UV dye in the system. Then let it start cooling real good and then park it inside or on the driveway at night. Then examine the condensation drain water with a UV light to look for dye. If you have dye in the condensate or see it dripping from drain tube, then the evaporator is the only place that it could be leaking from.

That said, if you're going to charge it your best bet would be a sniffer. If you don't have a recycle machine, then you will not only lose the charge that you put in it for leak detection purposes, but it is also illegal to charge a known leaking system.

A properly equipped auto a/c shop will either put in a leak charge long enough for diagnosis and then recover it (legal procedure) or use Nitrogen and a couple of ounces of R22 and a sniffer (also a legal procedure.)

The next time you are in the situation where you SMELL the refrigerant, take it for diagnosis or borrow a sniffer RIGHT AWAY!

a2t · #5 08-04-2009, 01:37 PM

OK thanks guys. Its sitting at an Indy right now, they are looking into it and I will pass along this info. I know the current charge had dye in it so maybe they will find it.

What is the metal rectangular box that the 2 lines go into right outside firewall on drivers side? That thing was dripping (perhaps condensate) but its definitely oily. I thought that was expansion valve, but larry mentioned it being on pass side so now Im wondering what that is.

#6 08-04-2009, 03:29 PM

I'm sorry! It is on the drivers side. My wife says that there's no such thing as "partially" deslyxic. Maybe the correct term is "occasionally" deslyxic.

a2t · #7 08-04-2009, 03:40 PM

ok heres what they came back with -

wonder how hard it is to change that thing out? he said it has lots of fresh dye on bottom side of it. also some dye on compressor hose at compressor but only a little. he thinks its exp valve.

what do you guys think is fair price for them to RR the valve/check/recharge? I think fastlane sells a "four season" expansion valve for like $40.

zeke · #8 08-04-2009, 03:44 PM

easy! Much better than the evaporator core!!!!

#9 08-04-2009, 09:12 PM

Yes, it's a little hard to get at, but it's no hill for a climber. I've replaced mine for the same reason.

leathermang · #10 08-04-2009, 11:01 PM

That is wonderful news compared to the evaporator being the problem...

WHAT does FREON smell like ?

What does the dye used in AC systems smell like ?

dannym · #11 08-05-2009, 08:32 AM

Leaking oil is a definite sign of a leak in any refrigerant system.

You lucked out that it's not the evaporator core.
Your also lucky your TX valve is on the firewall. I have to get up under the dash to get to mine.

Danny

a2t · #12 08-05-2009, 01:56 PM

Freon is odorless, but they put in a scent that smells like cheap xmas tree air fresheners I guess so you know when its leaking. Kind of like natural gas.

So this 1s easier than 123 chassis? Could be a first!

rrgrassi · #13 08-05-2009, 02:32 PM

Quote:

Originally Posted by a2t

Freon is odorless, but they put in a scent that smells like cheap xmas tree air fresheners I guess so you know when its leaking. Kind of like natural gas.

So this 1s easier than 123 chassis? Could be a first!

Add the smell of rain to that as well. At least that is what it smells like to me, i guess because of the condensing moisture caused by the escaping freon.

zeke · #14 08-05-2009, 03:02 PM

To me, rain is the smell of low freon, but not the freon itself. I think it has to do with incomplete or partial de-humidification. Freon out of the can has a (very) slight chemical odor. Never smelled pine-sol like smell.....could that be the oil rather than the freon itself?

leathermang · #15 08-05-2009, 03:47 PM

Thanks for the smell descriptions guys... I have never smelled it so I was just wondering.