W210 Power problems this morning
 

So this morning on my way to work my 96 E300D started to give me some problems. About 2 minutes into the drive the car stated loosing power. The engine rpms would fluctuate and the engine would not run smooth. the transmission also started to shift rough since the engine speed jumped up and down. After having to stop at a stop sign I could not get it to accelerate past 10 mph. I also noticed that the dashboard light flickered as well. When I pulled over the engine started to idle nice again. I turned the car off and started it up and it was little better, but could not get the car to go over 40mph. It also ran really slow would not want to accelerate like usual, and I just felt that the engine ran differently. the k 40 relay i replaced a year ago, some 9000 miles ago. i am wondering if it could be the EGR valves? Any other ideas. I will see what happens on my lunch break. Also I am in New Hampshire so it was cold this moring, and there was a lot of frost. Not sure if the temp could have done something.

We could use some additional information . . . how many miles on the car, what kind of fuel, what kind/weight of oil, any warnings from the dash (check engine light, etc.)?

W210 mPower problems this morning
 

NO check engine lights on. I think I used 15 40 oil last time. get diesel fuel at shell or mobil. I just drove it back on my lunch break and it had no problems. NOt sure if it was thing in the cold or not. It kinda felt like the engine was choking could not muster enough power to get the car going.

219k

Might be a batt voltage issue? You can monitor voltage while driving using CCU screen #23. Press and hold REST for 5-6 secs, then use "auto" button to toggle through screens.

I see you are in NH. How cold was it this morning? Might be you need an antigel additive although I would have thought the fuel you have been buying is winterized.

it was around 30 this morning when i took off for work. The doors were frozen and were hard to open. I will try the monitor on my way back home today and see what happens.

Another poster mentioned anti-gel.... I have the same model car, and last winter had the same exact issue. Just prior to a cold snap, I had filled up, and did not have the proper amount of anti-gel on hand for the amount of fuel I put in. Next morning, the car did exactly the same thing yours did. Could not get past 40 mph, and the engine ran rough. This lasted for about 5 miles, and then cleared itself up on its own. I think the fuel in the lines had geld up a little, and once it started to draw fresh fuel from the tank, the issue was resolved.

It won't hurt to add some power service (white bottle) additive to prevent gelling. I also have run into water collecting in my fuel system this time of year which is why every fall I replace both filters. If it has been over a year since you replaced the filters you might consider that as well, especially if you saw some white smoke out the tail pipe while it was giving you trouble.

I agree with nhdoc. If your fuel filters have not been changed in a while the fuel flow rate may be already marginal and compounding the delivery of cold/gelled fuel. The engine is fuel starved until everything heats up and starts thinning out the fuel so it passes through the partially clogged filters faster. I would start with replacing the primary and secondary (can) filter.