I just bought my car and I love it. I drove 300 miles to get her. The car is a '94 E320.

My baby has developed a problem though. When sitting at idle with the A/C on and the car in gear I sometimes feel a bump or a thump. I first though the tranny was acting up, it felt like it was shifting in and out of gear. After a few trips though I have found that if the A/C is off (or in EC) or the tranny taken out of gear it stops right away. When it does this bump or thump the tach drops 100 or 200 rpm. So for this to happen the A/C must be on and the tranny must be in gear at idle.

Has anyone ever had this happen to their car? I feel like it may be the tranny mount but the car shifts into R and D ok. Any help you guys could give would be great. In case I can't track this down myself does anyone know of a good mechanic in the Atlanta area?

Thanks
Ken

Does it occur as the A/C engages/dis-engages? Worn motor mounts?

[/uninformed guess]

__________________
62 220sb
67 250S
72 280SE 4.5
74 280C
77 300D
82 240D
85 190E 2.3
86 300E RIP 12/28/09
85 300SD
92 300D 2.5
00 E320 Current
Over 1,000,000 miles in Benzes, Since66

....and a whole passel of BMW 2002 and Tii

Just happend to me last week, posted here but Larry said he never got in to that situation before. I did not solve it yet.
A/C compresor

__________________
New Addition to the family
2013 Passat TDI 5Miles
2004 E500 4MATIC Wagon 95k
1996 E300 Diesel 173k Sold
1993 300E 2.8 230k Sold
1994 E320 White Wagon 373K Sold
Still dreaming about ....500E


Radu Negru

Yes, it seems to happen when the A/C engages, but not always. If I were to go out and start the car now which hasn't been started all day it will not happen. Once the car warms up it starts to act up. I also thought it may be the mounts, is there are way to tell if they are bad?

thanks

Radu, Thanks for your reply. My A/C cools great so I don't think it is the A/C itself, it just seems that I can feel it engaging and my RPM's dip a small amount for a second.

Same situation on my side. Car is acting up when is warm. Also the motor mounts are good( no other vibration I can feel).

__________________
New Addition to the family
2013 Passat TDI 5Miles
2004 E500 4MATIC Wagon 95k
1996 E300 Diesel 173k Sold
1993 300E 2.8 230k Sold
1994 E320 White Wagon 373K Sold
Still dreaming about ....500E


Radu Negru

After spending all night reading, I have found a post from 2000 that lists exactly what my car is doing. When I read post #1 it didn't click but when I read the op's #5 post it states to the word what my car is doing. The op never posted what was done to correct the problem though. I assume it had to do with replacing his spark plugs and resistor tips. He says that when the original plugs were replaced his problem went away for about two weeks, and then two of his plugs were bad again. I am going to order new plugs and resistor tips, but I am not sure what the resistor tips are.

Below if the post from 2000. Input is appreciated.


E320 misfiring at low idle

I do have new coil connectors and spark plugs 5000 milea ago and the car runs beautiful. I think is not the case. I suspect trnsmission mount. I am tryng to do it.
I will keep you posted

__________________
New Addition to the family
2013 Passat TDI 5Miles
2004 E500 4MATIC Wagon 95k
1996 E300 Diesel 173k Sold
1993 300E 2.8 230k Sold
1994 E320 White Wagon 373K Sold
Still dreaming about ....500E


Radu Negru