1985 300D Terrible, Rotten Eggs smell from HVAC system?
 

A week ago, I replaced my AC compressor on my 1985 300D, pulled a vaccum and injected about a 16 oz of freon into it and then gave up since I was late for something else.
I drove the car for about a week like this.
Today I noticed the most horrible sound coming from the car's Passenger, and not, engine compartment. It smelled a little like that rotten eggs smell you get when your Catalytic Converter on a conventional car is plugged. It was so bad that the kids working at the MacDonalds Drive Thru window thought it was their food before I told them it was my car..
When I came home, I drew a vacuum on the system, pretty sure that the smell had to be AC related. I noticed a lot of black oily goo at the base of my air operated vacuum pump.
I am not sure if any of this smell is HVAC related, but I am pretty sure it is. The smell is not coming from the engine compartment and is not exhaust related, as far as I know.
I dont get the smell when the car isnt running. The only other thing I can think of is that rain water got into a body cavity, but I dont think so.
1985 300D Rotten Eggs smell from HVAC system?

I had this exact smell just this past week and had to endure it for about 3 days. In my case the battery was being over charged by the car and basicly getting fried, which caused the rotten egg smell to leak through the battery vent. The voltage on mine was nearly 15 when it should be 12. All I did was relpace the brush part in my alternator, and the problem now is gone. These brushes get worn over the years, and can lead to problems like these. Also make sure you check your battery for proper water level, since it is probably dry from the overloading. Good Luck

Isn't that about half the freon your AC needs ?
Did you run the Air Conditioner with that amount in it ?
Did you put a new reciever dryer on your car when you replaced the compressor ?
Did you add oil to the system for the items you replaced ? What kind of oil ( if yes ) ?
Did you flush the system ?
THis last time you pulled a vacuum... what did you do with the R12 ? Do you have a recovery system ?
How many inches of mercury are you able to pull with that air compressor operated vacuum pump ?

Isn't that about half the freon your AC needs ? Yes you are correct.
Did you run the Air Conditioner with that amount in it ?
Yes, I was in a rush to go to CT
Did you put a new reciever dryer on your car when you replaced the compressor ?
Yes, I followed procedure
Did you add oil to the system for the items you replaced ? What kind of oil ( if yes ) ?
I added Ester Oil
Did you flush the system ?
No, I didnt have the equipment
THis last time you pulled a vacuum... what did you do with the R12 ? Do you have a recovery system ?
There was no R12, i am using 134.
How many inches of mercury are you able to pull with that air compressor operated vacuum pump ?

The standard vacuum. Thanks!

Dead alternator
 

I havent checked yet but THANK YOU!!

Dead mouse in the AC drain tray.

Peter

Dead mouse
 

Your post really got me thinking so I woke up at 3 am and got my shoes on and got dressed and got all my tools and went out to my car and took out the battery and checked.
I couldnt find a dead mouse.
Is there a procedure to do this in the Mercedes Service Manual?

In South Jersey ? At 3 am ? You could get shot by someone trying to protect your car from a car thief.....
Next time you wake up compose an email to DR. Phil about your desire to go outside.... then go back to bed.... :D

The mouse, if there is one in there, is in the drain tray that collects the condensation from the evaporator and drains it out the tube over the transmission. He only stinks badly when he's wet.

You won't find it unless you take the AC case apart inside the car.

Good thing it that it will eventually disappear on it's own, but I highly recommend checking.

You will have to dissasemble the dash.

Peter

I removed the dash..
 

but I still havent found a live or dead mouse.
To get at the AC Box I removed my AC Compressor and hoses and I still couldnt get a good shot at it. I am now trying to work from the inside of the car. I also have taken apart the Console Box and Glove Compartment.
If the mose is in the HVAC vents, I will remove the entire system.
It is possible the mouse is inside another area of my vehicle. To that extent I will take out the seats and door panels tomorrow.
Is it possible the mouse is still alive?
If this is true, I dont know how to remove it. If I I trap it and injure it my daughter will not speak to me.
Luckily I have been able to jury rig a lot to keep my car operational and still running so I can get to work. I get a lot of funny looks and hear a titter or two from the people in my Carpool but maybe thats because they admire my technical resoucefulness.

If there is a mouse in there, its in the drain tray, next to the heater core and the evaporator. It's very, very dead and rotten, belive me!

Leave the doors and seats alone, its in the interior guts of the AC system, where the water collects. Reconnect all the AC hoses, thats all in the engine compartment, mouse is inside the dash. Follow the pipes that go to the dash vents, he's inside that box.

Short of disassembling everything, try some Febreeze down the air intakes with the AC running, you may get lucky and eliminate most of the smell that way. Also, check to make sure the drain isn't plugged -- it's just above the transmission in the center of the car. Pooling water growing mold will stink, too.

Peter