nalaskier

The first time (about 3 weeks ago), I was driving down the freeway in Birmingham while climbing a hill I noticed an immediate loss of power. I had to put the "gas" pedal to the floor and went from about 65mph down to 45-50mph. The RPMs would only max out at around 3,000rpm. The engine never did die. We made it to a local shopping center. All the while not being able to get above 35-40 from a stop (with the pedal to the floor). We called the dealer but the service department was closed on Sunday. We ate lunch and were prepared to get a loaner from the dealer and leave the GL. However after lunch, the GL ran fine and has until today when it did the same thing. My wife was going on a trip and she experienced the loss of power. After lunch (and a cancelled trip), she drove home and the GL is now running fine.


At first I thought maybe we has some bad diesel (the tank had about 50 miles till empty), maybe a clogged fuel filter. The check engine light has been on for a temp sensor on the exhaust. The SA had to order a part, told us it was an MB problem that they couldn't figure out and would happen again but to drive it as it wouldn't affect it. I have also noticed about a 3mpg decrease in fuel economy on the hey. From 26-27mpg to 23mpg.

Any body else with similar experiences. Wife is taking it to the dealer in Tuscaloosa tomorrow.

StevethePilot

Usually when you lose all power, your car's gone in to "limp mode" (as in "limp to a dealership", maybe to minimize further damage? No idea if that's the reason, just a thought.) It's happened to me several times, usually due to turbo problems but once because the computer decided the fuel didn't fit its requirements (never got any information back on that but still paid for the fuel system drain and flush). I'm not sure if the temp sensor would affect MPG or if it would cause a "limp mode" situation, but that would absolutely be worth asking your SA about.

nalaskier

Update. After a trip to the dealer the SA had heard of 3 other instances of diesels doing this same thing. Not sure if he meant 3 at this dealership, 3 in Alabama, or 3 nationwide. He said MB as aware of it but didn't have any fixes for it. ( like the temp exhaust sensor that was replaced today, but the SA said it would go out again). Anyway it is running fine for now. The dealer did make some adjustments to the engine. We will see.

I am wondering if it is a bad sensor that controls fuel/air mixture or maybe water in the fuel. I have ruled out debris in the fuel filter.

43221B

Did you ever figure out what caused this? My 09 320 did the same thing yesterday about 45 minutes after getting a half tank of fuel. Anyone else experience this? I'm thinking it was bad fuel as I filled up at a station that I haven't used before while out of town.

alx

bad fuel or clogged fuel filter.

or both.

very very common.

43221B

After the power loss, which was almost identical to what was described in the original post, I shut the engine down and it has run fine now for the past 250 miles or so. I am out of town and still have a 650 mile return trip home. What should my course of action be? What are the chances I have another problem on the return trip? Obviously I will take it in for service when I get home but unfortunately there are no dealerships within a couple hours of where I currently am.

Thanks in advance for the advice.