20 Most Recent 1992 Mercedes-Benz Mercedes Benz 300 Class - Page 3 Questions & Answers

When you ran out of gas, the engine could have developed a small misfire from low fuel pressure. This is a false alarm, have the light reset, and if it comes back you will have to pull the code from the computer to further troubleshoot the problem.

To reset the computer you must disconnect the battery from the car and let it sit for a few minutes. re-connect the battery and the light should come back on.

good luck, please rate

you should have a 722.2 or 722.3 transmission . Theese are 4 speed but not overdrive. The vacuum line going to modulator should be manifold vacuum , mean it is supplied directly off the intake manifold and should be 16 to 18 hg at idle and nearly zero at wide open throttle. benz loves to use nylon lines to source vacuum for different things and they get hard with heat and age and break. Nobody could remove an engine on a 20 year old benz and not break one somewhere.

Hi.

Center front of cowl, behind panel..



I hope this helps.

Thanks.

code reader at auto zone only works with engine light on sounds like fuel pump or cloged filter

Is it a diesel car? If not then please check the spark on the spark plugs. May be there is no spark.

I assume you have checked the cooling system to ensure that first, that it is completely full of coolant (not just the overflow tank) with no air locks and second that there are no leaks anywhere and the radiator cap is in good condition. The heater hoses and those pesky little bypass hoses in the cooling system tend to go hard and split if they are over 10 years old, allowing coolant loss. Those spring type hose clamps tend to be less effective in clamping as the hoses become hard. Worm drive ones are the best to use. Both cooling fans operate together on most larger cars.

If there are no leaks or air locks, the over heating could also be caused by a clogged radiator (more than 15% restriction in the radiator flow capacity will cause overheating problems), a faulty water pump or a faulty thermostat.

If there are no leaks and water pump and thermostat are working correctly, but undetected loss of coolant once the engine heats up, then it could indicate a problem with the head gasket (Usually caused by allowing engine to become excessively overheated when cooling system has run dry) allowing very hot high pressure combustion gases into the engine water jacket, which super heats the coolant in the engine block, which then boils off, and is released via the cap.

If unsure take vehicle to a cooling system specialist and have them do a pressure test and more thorough diagnosis.

What kaind of repair was made in the first place ?

Switch on column sounds like it is bad.

In all of the other forums the mechanics talk about replacing or checking the fuses on the OVP which is the Over Voltage Protection Relay located on the right side of the engine compartment behind the battery. That might be a good place to start checking.

You must turn the car on after alarm goes off. Door locking and unlocking dont work after the alarm goes off. Its like you break a window to get in anyone can lock or unlock a door thats why its tied to the ignition.

Worn discs or bad fluid.

Yes replace the hoses to original. The viscous fan is and easy DIY job just takes some time. Try replacing the OVP and ignition coil to help with the hard starts and maybe the fuel pressure regulator and head over to benzworld.org and peachparts.com for more help.

Fluid is checked by the red/orange cap on the passenger side of the engine by the fire wall. Flip the cap over and pull out. Fluid gets put in that tube with a funnel.

Ok Its long and drawn out so ill send you to a couple of sites you can search for pictures and write ups. Benzworld.org and peachparts.com.

Aux heat pump maybe failing. Its on the passenger side by the battery. Follow the hoses. Its moves water to the heater core.

Rust, engine wiring harness upper and lower, tune service, head gasket, Plugs are correct Bosch F8DC4's or equal.

Head to benzworld.org for help.

Pull one at a time and look at it to see if it is blown.

Its you headlight/bulb out indicator relay under the screwed down area behind your fuse box. Its longest relay in there. Failure rate for that age of vehicle is high for that part. Expensive new but cheap if you can get them froma bone yard. Also most W126 body styles have them also like the SEL's and SE's.