This past week after having not drivin my SLK for a week, I started her up and rev'd the cars engine like a bonehead thinking that would warm it up quicker. Well after I rev'd the engine and put it in gear (automatic) the car chugged, like I was popping the clutch or it wasn't getting enuff gas. I turned this car off and then back on and it ran better but I notice now that I can't accelerate quickly like I use to be able to, now I have to slowly bring the car up to speed, if I floor it, it goes but once it get to 40mph I notice there is slight hesitation in power then I have to let up on the gas an bring it up to speed slowly. I sheduled my car for an apt with Mercedes next week just to make sure I didn't F@$K it up. If anyone has any ideas as to what is wrong or what could be causing the problem please let me know

Uo! I drive mine once every 2 weeks and when I start the engine I have to warm it up for at least 5 minutes… if I don’t do so it lags of acceleration, power output is too irregular and I don’t want to break some mechanical parts. After that I drive it slowly for a few kilometers and everything goes right and you can drive as you want.
It’s curious, because the engine seems to sound different when it’s warmed enough, a little less “ventilator”… I think it’s the compressor, don’t know.


Mine is a 6-speed manual transmission.
I lack of mechanical knowledge, but what’s sure is that you have to let your car warm by itself before driving it, even more when it was parked for a while. Cars tend to wear & tear quickly when the engine is cold, so rev it just after starting the engine can easily break some internals parts, from pulleys to pistons and all that stuff (sorry for not giving more accurate tech names…). A friend of mine had a problem like this with a 14-years old Mazda, he crushed something from the engine when warming it manually and the car started smoking... the car parked for some weeks.


Your problem? It was probably caused, or enhanced, by the way you warm your car.
Don’t know anymore.

Lack of power. I would cheak your spark plugs. Also when was it last seviced? It could be a number of things. O2 sensor, air filter, Transmission. Let us know how it appointment went and what was wrong. GOOO LUCK

Yea, I think I know what the problem is, I haven't had time to put it in the shop but I've talked to someone who had the same problem as me. It's most likely the Air Mask Sensor, I was told the car will seem to "CHUGG" when you accelerate quickly if this sensor is out. Anyways also just so you know... MB repair is not cheap and they are pretty much "D!#Ks" to deal with esp on the phone. I called on MB dealer and the part was $495 plus $98 per hour with an est. or two hours to install, the other MB dealer said the part was $382 and $91 per hour. I think I'm gonna have to calm down a lil before I take it in cuz it seems MB is a big RIP!!! but I guess I should have known that when I bought and SLK "UHHHGGG" "IT'S JUST A SENSORRRRRR!!!"

Oops, I just looked at the previous post, I didn't mean to say Air Mask, I ment to say Air Mass Meter. I ended up buying it on ebay for $288 and installed it myself from directions from Tech Tip website only took me about 20mins, car runs GREAT!!! just make sure you get a new air filter as well when you replace the AMM.

I had to take my car in last week for the same problem. Step on the gas and the engine does nothing, and then slowly starts to rev. I have a manual tranny, and the same thing happened every time i shifted. Fortunately, the car was still under warranty, and has been repaired. Believe it or not, they replaced the accelerator pedal!

2BLueSLK, did your accelrator pedal click prior to them replacing it?

I am getting a similar hesitation in power with my automatic. The AMM sounds like a logical solution, but the pedal? Anyways, my pedal click when you roll into it, so I may look at that first if yours did it.

On top of the power loss, I get a clicking under the hood. I notice when I park or drive by a solid object that bounces the sound back to me.

Thanks

Auto pedal clicks on hard push to floor as there is a kick down button under there.

Bazzle

The click is at the top end of the pedal, under light pressure from the foot.
Thanks

Spray silicone lube around pedal rear. Also check throttle pot on other end of cable under hood by hand.

Bazzle

Sound like the MAF.
Clean first. If fault goes for a while get a new one. $145 on Ebay.

Bazzle