1996 Benz C-280
Approx 230k mileageAbout 3 weeks ago 2 issues happened.
1-The Speedometer dropped off indicated 0 speed even while driving. The following lights also illuminated: PARK BRAKE LIGHT, DISC BRAKE. At first these would illuminate…then a few minutes while driving the speed indication would come back, and the associated brake lights would extinguish. After about a week the lights remain permanently illuminated.
2-Around this time, I noticed a rough idle, slow acceleration and lack of power going up hills.
Here is what I’ve done to attempt to correct:
1-Regarding the brake lights, I recalled my last brake service entailed replacement of the front brakes. I took the car to a local shop and they looked at the rear brakes and told me the pads were worn and a rotor
cracked. So, I had the rear brake pads and rotors replaced. However, the brake lights on the dash remain illuminated, and I don’t get a speedometer signal.
2-Regarding the idle/power problem, I put in some fuel injector cleaner (like STP) but that didn’t solve things. I also replaced the following:
a-Mass Airflow Sensor
c-Spark Plug wires
d-Spark Plug boots (but not ignition coils)This has still not solved the ugly idle problem, power problem nor restored speedometer and extinguish lights.
I took the car in today to a local shop to have the diagnostics of engine taken. After two different diagnostic machines, couldn’t get a connection between their machine (snap-on) and the car. They finally told me since the check engine light is not on in the car, there would not be any diagnostic codes to be read.
I am now ready to try something new, but didn’t want to blindly put more $$ into a action that is not going to solve the problem.
I am contemplating getting new ignition coil(s) but don’t know that this will solve the problem.
*** of note, when I do run the car I do detect a smell of gas that was not present earlier…but have not searched for a leak. **