Another Problem With My S500 W140!!!!!!!!!! - PeachParts Mercedes-Benz Forum

Folgado · #1 04-29-2002, 05:34 AM

Hi all

YES It's true a have one more problem with my 93 S500!!
The Car has 150 kmiles now and in one year I spent more than 10.000 USD with repair services from engine to suspension to gearbox, well almost everything.
The car ridded perfectly for almost two months UAUU!!! But now has the following problem:

When It's hot, really hot it refuses to idle, the engine quits and don't want to start up normally, one have to floor the throttle paddle so the engine can start, and then can not idle properly.
This only occurs when the car is very hot, and the ambient temperature is very hot also 86 F.
At highway riding the car runs perfect, this only happens when the engine has to idle.

SOMEBODY CAN HELP ME ABOUT THIS!!

Thanks in advance

Folgado
93 S500

Ashman · #2 04-29-2002, 05:41 AM

Nto sure if your car has one, but search for OVP, and read the posts. yours sounds like it could be related to this inexpensive part, which is notorious for similar symptoms and many others.

I would also have the codes read, it could be showing a fault code for something specific.

Good luck on your search.

Alon

Folgado · #3 04-29-2002, 06:27 AM

NO! my car does not have an OVP it's all controled by the main control unit, but has 4 or 5 fuses inside this box, can this be the problem?

Thanks anyway

Folgado
93 S500

Folgado · #4 04-30-2002, 07:49 AM

Hello all

Now I'm sure that this problem only happens when is very hot, if the ambient temperature is around 60 F there is no problem.

Does anybody have some idea of this cause?

Thanks

Folgado
93 S500

Folgado · #5 05-06-2002, 06:13 AM

Hi All!!

I send the car to the dealer so they can read the DTC's.
It is everything fine, it does not show a single error!!
I seriously suspect that could be the O2 sensor.
Can anybody give me a help about this?

Regards

Folgado
S500

rmasteller · #6 05-09-2002, 11:46 AM

With a car that complex, it could be many things. My "daily driver" is a much less expensive car, but it had numberous O2 sensors, both "upstream" and "downstream", go bad on it. Symptoms included:

Check Engine light on
Code regisered in OBD (On Board Diag)
Occasional fast idle
Occasional rough idle
Occasional stall from idle
99% normal operation while driving

I'm sure an O2 sensor would generate a code in an MB if it creates one in a cheap Dodge. I think you might need to look elsewhere if you don't have a code.

Since it happens only when the ambient temp is high, perhaps you need to look at air/fuel mixture sensors and systems. As the temp of air increases, it can carry more humidity and it gets less dense (less oxygen). I am not a mechanic by trade, I'm just trying to use my common sense.

Best of luck!