94 E320 w 74k on the clock - PeachParts Mercedes-Benz Forum

Hammertime · #1 06-22-2008, 08:12 PM

Recently I had an issue that my vehicle was giving me a prolonged start when try to start the engine. After 5 minutes or so and completely unexpected car would start. Got the fuel regulator replaced.Seemed to cure the issue for a day or so then again the problem looms.

Since then my serpentine belt snapped and just made a mess. I had to go for a new radiator, new belt, thermostat and mechanic found a relay that was not functioning correctly so we attributed the prolonged start to this relay.

Now my car runs at 100 not around 80C like usual. The car is always running hot between 100 and 110 and doesn't overheat but I am nervous. When driving the car is normal, 80 but get off the highway and wait for a red light and its well over 110 quickly. To boot the prolonged start issue has started again. I am frustrated as the mechanic is at a loss. We recently changed the fan clutch also and no change. He ran diagnostics and nothing...

Anyone live through this before? If so any help to offer?

nissanzx1 · #2 06-22-2008, 08:27 PM

What relay did he change? Was it the OVP relay? OVP is near the battery and looks like :

http://www.***************/secure/PartImages/0005405245.jpg

I had to replace mine just last week on Arthur Dalton's advice. Now my car starts properly.

On your cooling issue, is there any chance there could be air in the system or maybe not enough coolant? Was the radiator new? Try another T-Stat, 1st one may be faulty...

-GH

Hammertime · #3 06-23-2008, 05:53 AM

the relay changed did not look like this one. The mechanic found a bad relay with his meter as he noticed no current going to the fuel pump. Mine was green in color. It did start fine for a few days but has returned back as the problem.

I will ask on the thermostat....thanks for the input

nissanzx1 · #4 06-23-2008, 09:05 AM

The relay he changed was the fuel pump relay ~$25 part. It's good to have a new one. Here's what you need to do:

Open the hood all the way up and remove the battery and plastic shield behind the battery. Use a socket set and remove the OVP relay. This will be on the right side behind the battery located next to the cars main electronics hub. Detach the OVP by removing the screw and prying the harness off the relay.

Post here what the model number of your part is. The old faulty part is 000 540 52 45. If you have that number on your OVP, it has to go regardless. New part number is 000 540 67 45. The OVP is about $60 online and $90 at the dealer. You're not getting current to your fuel pump, because the OVP is not sending it from the battery. Trust me on this, I just went through it all with my '95 E320.

On the other issue, did the mechanic run the heater on the climate control after the new coolant was added? I always do this to get coolant all over the system. You can end up with an air pocket otherwise... I have had cars run too hot if this isn't done... Your car should have an 87 degree C T-stat. Check that he didn't use a higher value one...

Make sure he didn't use green coolant. You need clear coolant Zerex G-05. It is made to protect aluminum components. If you have the green, it needs to be flushed and replaced.

-GH