I start it, no problem, drive it for a few minutes and then when I stop at the light, it kind of starts freaking out a bit, kind of like it may stall out. This only happens basically when the car warms up but hasnt been driven much yet. I was just wondering if anyone had this issue.

Note: I havent done the spark plugs, fuel filter or air filter quite yet. Doubt it was done, mileage is in the 70's, 99 CLK 430.

 

Had the same problem, same symptons as yours, turned out the motor mounts needed replacing. Engine is smooth as silk now.

 

NYC-CLK: other things that people have claimed to work are top end cleaner and MAF replacement.

RED-CLK: where did you have the mounts done and how much was it? How did they diagnose the problem or did you just tell them to replace the mounts?

 

Its most likely the motor mounts. If your car was really freaking out then I would guess a sensor but motor or tranny mounts would be my first guess.

 

i had the same problem and it was the MAF. it would usually happen after i gun it,then at red light i would feel it wanted to stall but never did.had the sensor replaced and that fixed everything

 

I went to my independent Mercedes repair shop, "Goody's Auto" in Scottsdale, told them how it idled rough when it was cold and in no time they diagnosed the problem to be the mounts. Charged me $194 for 2 motor mounts and 1 transmission mount. Labor was $160. All but $100 covered under my extented warranty. Won't be long before the extended warranty will have paid for itself!!

 

My cad did this when the MAF when bad, except it actually stalled out and really freaked out on me. Brakes went out, car shut off, apparently the MAF going out will affect the rest of your electronics. Replaced the MAF and everythings cool now.

 

You got a REALLY good price on those mounts. I am getting mine done thursday. I have a hook up at mercedes and it still cost me $211.47 and I will pay my friend $120 to put them in. I'll post and tell you guys if the rough idle goes away.

 

How much did you guys pay for the MAF's?

 

It looks like I am going to buy a MAF sensor and keep it in the glove box.
Kind of what I used to do with Main relays on my hondas.

Do 320's have the same problem as the 430s with the mounts going bad?
Mine is a 00 with 33K, I hope I don't have to change mounts.

 

This might sound stupid, but wouldn't newer motor mounts just hide the shaking more? The problem is the rough idle...changing motor mounts is like turning up the radio to fix sqeaks and rattles in your car.

Maybe not.

 

I had a rough idle, and the dealer changed both the motor and transmission mounts. And now I still have the rough idle! I agree with Str8, the mounts are more likely to be a symptom or victim of the idle issue.

 

wow...

 

It's not that unusual of a problem, the failing of the motor mounts, When they fail, the engine seems to be idling roughly when in fact the bad motor mounts are just transmitting the normal engine vibrations into the cabin making it seem like there's something wrong with the engine, especially when the engine has not warmed up fully. The shop that repaired mine was well aware of the weakness of the Mercedes mounts and have replaced many of them. It's a common problem.

 

LOL Thats what I said, I had to reread his post 5x times and I am still confused.

 

Guys I appreciate the help.

Bad mounts cause a steering vibration where you can feel it, its a different type of rough idle.

Mine is like, the car is smooth as hell, but you have this up and down thing happening where it feels like its about to stall out, but its so quiet that its playing with you almost. Based on what everyone has said so far, I'm 99.99999% sure, my problem is the MAF.

 

And so the question of the day, how much is a good price for a MAF, and where do I find it?

 

Good price is under $200. Check on E-Bay. I might have one so PM me if you are interested at $200. If you can get it cheaper then go for it.

 

FYI - I changed my MAF and it didn't solve the symptom that you are describing although mine wasn't close to stalling it just kind of ebbs and flows like the tach is a yo-yo (not visually, but by feel).

 

thats basically what mine did, the stalling part was maybe a little overblown on my part. Probably was nowhere close since all I did was put in in neutral just to be on the safe side and it basically went away.

So did you take other steps to solve it?

 

I have experienced this same problem...come to a stop, step on the gas, and the engine sputters like it wants to stall. Anyway, I've been trying to get this issue resolved for well over a year or more and the MB service personnel couldn't locate the problem. These techs these days cannot diagnose a car without hooking it up to a machine. If the diagnostic computer states that everything is okay with no error codes...everything is okay with the car in their mind. WRONG!!!

Finally, I took my car to a repair facility owned and operated by car enthusiasts. What they found was an information bulletin put out for the following mercedes benz:

Title: Engine Controls - Rough Idle After Coming to a Stop
Date: August 21, 2001
Order No: P-B-07.65/14

Subject: Model Year 2001 - All Models with ME 2.8 Injection System (M112/113 Engine) - Except M-Class and AMG

If you encounter instances of rough idle or hesitation after coming to a stop at engine operating temperature, the engine control unit (ME-SFI) may be causing the engine to run lean. This includes Engine Control Module part numbers (see below) installed in the following models during production (phase in) from December 2000 to end of May 2001 (phase out): C-Class, E-Class, S430/500, CL500, SLK320 and CLK320/430.

To resolve, please install an updated ME2.8 Engine Control Module as follows:

Affected ECU Part No. Replaced by Updated ECU Part No.

112 153 0079 112 153 0879 for M112 (C-Class, E/S320 2 & 4WD, CLK320)
112 153 0179 112 153 1079 for M112 in SLK320
113 153 0079 113 153 0479 for M113 (E430, S430/500, CL500, CLK430)
113 153 1279 is the replacement for my CLK430 ($1200.00)

NOTE: Before an updated ECU is installed, ensure that all engine related systems are within specification. This software update will not compensate for any system malfunction.

Version codes have not changed, therefore use the version code from the old ECU. Parts are available through the PDCs.

The bottomline, unless your service representative checks the information bulletins put out by Mercedes Benz of known issues during your routine maintenance you will continue to encounter these problems when they could have been solved by simply reading the issues bulletins instead of relying on the diagnosis equipment alone. In the future, make sure you ask whoever works on your car if they check the MB bulletins each time they work on your car.

The ECU is EXPENSIVE (@$1200-1500 to replace). Just hope your car is still under warranty if this problem occurs; otherwise, get ready to write a FAT check.

 

For the people that are experiencing hesitation after stopping, you probably have a bad MAF. For the people that experience vibration when STOPPED at a light you need new engine mounts (might as well do the trans mount while you're at it). Especially if the vibration goes away when you put the car in neutral. Dont believe me? Have someone put your car in drive with the brake applied and pop the hood. Put your hand on the engine (put it on the airbox so I dont get sued). If you feel the engine shaking you need engine mounts. If you dont know anybody or dont trust anyone to put your car in drive just push the emergency brake (make sure its working) and put the car in drive and you should be able to look under the hood without the car going anywhere. Engine mounts are known to go bad on these cars. You will not feel hesitation when accelerating if the mounts are the problem. Changing the ECU would be my last resort.

 

I didn't post the ECU information as a means of telling folks to go out and get a new ECU. It is only one of the options to check while experiencing rough idling and the car feeling like it's going to stall. MAF or engine mounts may have been the problem in some of your cases, but in MINE it was the ECU that caused my rough idling and sputtering after taking off from a stop.

 

First of all what is a MAF and ECU?
I own a 2004 CLK 320 runs very well,however at stops (once in a while)it looks like it might stall,even the battery light comes on saying take it to the shop,I had twice at the dealer,they say the computer does not show anything,they kept it for the day sent somebody home with it,of course it did not do it...suggestions please.
I believe it is a sensor or computer chip,and not engine mounts??
Thank you for your help all.
fred

 

I think this is it

MAF = Mass Air Flow sensor
ECU = Electronic Control Unit