Common Mercedes 190E Problems

In an attempt to briefly summarize common problems of the Mercedes 190E, I've compiled this page to help you self-diagnose and solve any problems you may run into. The following list describes the most common problems and solutions to them. You can click a title and jump to that section. The diagrams on this page are compiled from various sources, most notably the BenzWorld Forums, 190 Revolution Forums, and my Mercedes 190E Shop manual (intended for use only by trained Mercedes mechanics), so I make no claim of ownership to these diagrams.


1. Oil Light Comes on Frequently

Oil Light Comes on Frequently
For starters, a background on *why* this happens would probably be helpful... As you can probably imagine, when your engine works harder at higher RPMs, more oil is being pumped from the oil pan to lubricate the engine, and the level in the pan is temporarily lower than normal. There is an instrument in your oil pan called an Oil Level Sending Unit, which detects how much oil is in the pan at any given time. While not a perfect way of measuring the actual amount of oil in your engine, this is about as accurate as you can get.

Mercedes documentation for the 190E states that, on a properly functioning engine, you should not be losing any more oil than 1Liter/1,000Km or about 1.06 quarts/621.4 miles. So, as long as you're within this range then a lack of oil probably isn't the problem.

To diagnose the problem, first check your oil level and make sure that it's pretty much topped off. Some people may disagree, but it's not a crime to overfill your engine by about half a quart because you've got an overpressure release valve in case it's way too full.

Next, read the instructions and follow the flow chart below, and determine if the sending unit is bad. You'll need a multimeter that can measure Ohms (resistance) for this test, and they can be bought at many stores for around $25 for an inexpensive model if you don't already have one.

If the sending unit is the problem, the least expensive place I know of that sells an actual OEM replacement is at the following website. You'll need both a new unit and an O-ring, so both links are provided. The whole job can be done DIY for less than $50. A shop will charge in the ballpark of $150-$200 for this problem including parts and labor.

Oil Level Sender (about $37)

O-Ring (about $1)

If, on the other hand, you discover that the oil level sending unit is working great, then I'd venture to guess that you're probably just driving it harder than you did when you initially purchased it. Either way, not fixing the problem definitely won't harm your engine, but you won't know for sure if you need to add oil unless you check the dipstick.

Last Updated: June 5th, 2005