PeachParts Mercedes-Benz Forum - View Single Post

tinypanzer · #28 08-19-2009, 07:30 PM

I'm not sure if I buy the theory that 7 degrees difference on the T-stat is going to be a big mileage buster. Now, if the engine was having difficulty getting to 80c, then perhaps, but 80c is in the normal range.

If it is indeed running that rich, there should be soot accumulating in the tailpipe. Worth a check.

If you really are burning that extra gas, there aren't too many things that can cause it. Leaky injectors, a leaky cold-start injector, a leaky fuel distributor O-ring dumping gas into the air bowl, bad temp sensors, OVP relay issues causing you to run purely on mechanical. I would expect to see rough running and dashboard lights if the OVP was bad, though. Perhaps a stuck plunger on your fuel distributor. You can check for that by putting the ignition to ON with the motor off, the air meter flap should get much harder to push on with the fuel pressure from the pump. But, again, I would expect to see rough running with that scenario.

You could have a leak in your fuel line, and you're just dumping your gas on the road...... Check the banjo fittings on the pump and filter. Mine have leaked in the past..... Something tells me you'd be smelling that, though.

Just for fun, here's an easy thing you can try. Take the plug off the main temperature sensor by cylinder 6, turn the plug 90 degrees and plug it back in. What you have just done is switch which computers are running on which temp sensor element (there are two in there). See if your symptoms change noticeably. If so, probably a bad temp sensor.

Also, make sure you're not running platinum spark plugs, and check to see that your cap and rotor are not damaged.