Q: Mercedes Benz 1997 E230 stumbling engine

asked by on October 11, 2016

I own a second-hand Mercedes Benz 1997 E230 WD210.

Occasionally, while driving, the car has had some rough stumbling i.e. choking when accelerating. This happens even at high speed, 80-100kph. Once, it even caused the car to turn off its engine when accelerating out of a traffic light.

I have noticed that the problem seems to arise when the fuel tank is more than 75% full.

In the past 18 months, I have had the fuel pump, fresh air intake and camshaft sensor replaced. It seems that the problem has improved, but not disappeared entirely, causing me some anxiety when driving it over long distances.

What should be the problem?

My car has 18000 miles.
My car has an automatic transmission.

The information given states two different vehicles. I will be addressing the first (E230). Its possible with the age of the vehicle that you hare having several issues. You are correct to address sensors, air, and fuel. All of them can cause issues like these.

Lets start with fuel. When you had the fuel pump changed, did you also replace the fuel filter? This should have been done at the same time. The fuel injectors can also be dirty and may need to be cleaned.

If you have not run the vehicle for codes, you will want to do that almost immediately. That way if the computer is picking up on something going wrong, you can start there with your diagnosis.

Oxygen sensors can fail as well causing drivability issues. Again, most of these sensors will trip a code in the computer. However some will not, or some may not be testing bad enough at this point to sound an alarm.

Start with trying to maintain some of the important fuel system components and test everything related to it as you proceed. Start with the simple fixes, and work your way to the more complicated systems. If you would like to have an expert pinpoint the issue in person, a qualified professional from YourMechanic can come to your car’s location to diagnose the hesitation issue so that this gets repaired correctly.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing


Experienced Mechanic?

Earn up to $70/hr

What others are asking

Car won't turn over but has new battery

YourMechanic next door was most likely correct and you have a problem with the key anti-theft system disabling the vehicle. You will either have to have a specialized locksmith come to you, program the key and make new ones, or...

Battery light on, temperature gauge maxed out, A/C system not working correctly

Hi, thanks for writing in. What you are describing happened to me personally a few weeks ago. It sounds like one (or both) of the accessory drive belt(s) that turn your alternator, water pump, and power steering pump is broken....

My car keeps shutting off

Hi there. From the description you have given, the charging system needs to be inspected. First, the battery needs to be charged (https://www.yourmechanic.com/article/how-to-recharge-a-car-battery) and load-tested. Assuming the battery tests good. The battery terminals are clean and tight (https://www.yourmechanic.com/article/how-to-clean-battery-terminal-connections-on-a-car). From what...

Vacuum hose is off and oil is going fast

Hi and thanks for contacting YourMechanic. First you will need to fix the vacuum hose. all vacuum hoses need to be either hooked up or plugged off is not in use. For the oil consumption, check the tail pipe for...

Wheel hop/ wobble

Hello. There are several components that may be causing these symptoms. The easiest to check is the condition of the tires. If they are cracked, warped, low, misaligned then you will possibly have these symptoms. More likely it is related...

I cannot find the neutral safety switch. Where is it?

The neutral safety switch on this transmission is called a transmission range sensor. The sensor is located on the right front of the transmission looking from the front of the vehicle. The connector should have an 8 pin connector on...

Car stalls when I fully brake after I drive

Hey there. This is a common sign of a failing idle air control valve (https://www.yourmechanic.com/services/idle-control-valve-replacement). The idle air control valve monitors the air intake as it is mixed with fuel prior to being injected into the engine. This valve is...

My clutch pedal won't come back up fully. The main reservoir is full, even over the MAX.

There are typically a few different possibilities for why a clutch pedal will stay on the floor (https://www.yourmechanic.com/services/clutch-pedal-goes-all-the-way-to-the-floor-inspection). It could be a failed clutch master cylinder, slave cylinder, failed fluid line, or the clutch has failed. If there doesn't appear...

08 chevy colorado 3.7 5 cyl should i be concerned that my alternator {2 months old} doesnt put out power for 2 min when cold start

Hi there. At first glance, I would not assume that the voltage issues you are experiencing is related to a faulty alternator itself. It's more likely that you have a faulty electrical connection or harness that is causing the inconsistent...

Related articles

Is it Safe to Drive With a Faulty Knock Sensor?
Symptoms of a bad or failing engine knock sensor include slow acceleration, reduced fuel economy, and the Check Engine Light turning on.
Symptoms of a Bad or Failing Speedometer Cable
Common signs include the speedometer needle wavering or not moving, squealing noises behind the dashboard, and the Check Engine Light coming on.
How to Replace a Car Battery Temperature Sensor
The battery has a battery temperature sensor that can fail if the Check Engine Light comes on, the battery voltage is low, or the RPM curve surges.