300e 2.6 gets *Sluggish* at times!
 

Hello All,

I have a 92 300e (M103 2.6) w/ 126k...
Its weird!, sometimes the car has brisk acceleration from a standstill, other times, it is *extremely* sluggish during acc. I can floor it literally and it will just slowly gain speed. It acts as if it was (for example), a carburated car that had either "too much gas" [and was choking on the excess fuel], or "too lean" (and not enough gas)... I have replaced the spark plugs, air filter and cleaned the throttle body area of the car.. this sluggish symptom still persists.. BTW- this is a 1992 300e, it does start out in 1st gear. Any opinions? I have not replaced/checked the fuel filter. I have also been wanting to replace spark plug wires and replace dist. cap + rotor ( i suspect them to be original).. would this sound like an ignition or fuel issue? I will say that on occasion the exhaust does smell slightly "rich"..... any theories?? :) thanks all for your awesome help!

-Miles
92 300e 2.6 126k

Miles I would like to know what this is as well? Curious.

Haasman

Although rare at one time my car was doing much in the same. Turned out to be the coolant temp. sensor, had come loose, plugged her back up and she ran like new... If this is the problem she will be real hesitant during start-up on a cold morning. You might also change that fuel filter, I did that in the process of searching for my problem and it helped quite a bit. Good luck

Brandon

How did you ever discover that is was the temp sensor. Did you replace it or just secure the connection?

Haasman

One day I had enough and literally started searching and checking everything, noticed the coolant temp sensor was sitting on top but not securely locked-in. I plugged her up and the difference was instantaneous. :cool:

Brandon

Thanks. Ah yes, the old pull on the wire check. Often yields interesting results.

Haasman

Dash lights
 

I ran into this situation after I had jump started my car with reversed jumper cables and blew the fuse on my OVP (Over Voltage Protection dohickey). My battery was really dead from sitting around during repairs. My car accelerated very slowly with the OVP fuse blown. After repair, and with a really hurting battery my car still did the same thing. With help from the forum I was told that a crappy batter won't cut the mustard. With new, fresh battery, problem went away.

During the problem though My dash lights, ABS, ASR, etc, would flash.

Joel

Do searches under O2 sensors and fuel/air ratios. I would get the fuel/air ratio checked and set and then take a serious look at the O2 sensor.

Intruder

My 300E sluggish too...
 

I have replaced the cap, rotor, wires, plugs, fuel injectors, O2 sensor and OVP so far and no change. It's like the car has an intermittant vaccum leak which isn't possible in my opinion, unless there is an air valve that is opening and closing letting atmosphere into the intake manifold. If it was the fuel filter then it would do this all the time... right? I'm not sure if it is the fuel filter but what the hey, I've replaced everything else... I will check my coolant temp sensor too.

fuel filter
 

From my experience does not sound like fuel filter. If it was a fuel restriction I would think it would kick in at predictable times.

Good luck,
Joel

I wonder if it could be electrical?? Not sure what though??

92 300E SLUGGISH
 

Hi,
Did you get this resolved? My same model car just started doing this (sluggish), chocking feeling while stepping on the gas. Even when parked. This is out of the blue, no recent maintenance to blame on. I did a tune up (plugs, cable, rotor) about a year ago. Just haven't figured out how to replace the fuel filter. I pulled out the fuel pressure regulator though. Still debating if its bad. Any ideas? Thanks.

To replace the fuel filter, raise the right rear of the car and remove the plastic cover in front of the right rear tire. The fuel filter and pump are above that cover.

Good luck,

Sluggish 260e
 

I am having the same sluggish problem with my '88 260e. I have had this problem for months and noted that the car starts and runs absolutely fine for the first 5 minutes until the temp gauge reaches 60 degrees C, then the car gets really sluggish. Pressing on the gas does almost nothing and pulling out in traffic is downright dangerous. When the temp gets up to the normal 80 degrees the car runs fine again.

Based on the symptoms, my problem seems to be related to the engine temperature so I am thinking it might be the coolant temperature sensor. I had an old '75 Volvo with K Jetronic and it had the same problem which turned out to be the warm up regulator. The warm up regulator sat on the top of the head and adjusted the fuel injection control pressure based on the engine temperature. I'm not sure if the Mercedes has one of these or not but if it does that is another possibility.

If anyone figures out this sluggishness problem please post a follow up and I will do the same.

John, This is *Exactly* like my 300e 2.6 (same engine as your 260e)... In the mornings, the car drives fine (ample power) for approx the first 10 min. then, after it reaches approx 60 degrees...it seems to get the sluggish acceleration issue mentioned above.. Weird! hmmm.. do you think it could actually be this coolant temp sensor? I did reseat the connector on the sensor, but it didnt seem to change anything...

-Miles

Does a 1989 300E have a coolant temperature sensor?? Where is it located??
My car has exhibited similar symptoms for a couple years and all other components mentioned in these posts have been replaced.

Thanks