I have a 91 300 SE. The car has recently developed an intermittent problem where the car will cough and sputter at idle. When the problem pops up acceleration is also pretty poor. I also noticed today that the oil pressure gauge only registers about 1 on the 0 to 3 scale when at idle. At speed the oil pressure gauge pegs at 3. I have already replaced the OVP relay so it is not the problem. Any ideas. (Note the oil pressure problem may or may not be related to the idle problem).

Sincerely Eric

When was the last time the fuel filter was changed? What about spark plugs? I'd take a look into those 2...
Good luck.

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2006 E350 w/ 155k miles (Daily Driver)

Previous:
1993 300E 3.2L Sedan w/ close to about 300k miles
2003 E500 Brilliant Silver (Had 217k miles when totalled!)
1989 300E with 289,000 miles (had for <1 yr while in HI)
03 CLK 500 cabrio (Mom's)
2006 C230k (Dad's)
1999 S420 (Mom's/Dad's)
2000 C230k Sport sedans
2001 CLK320 Cabrio (Mom's)
1995 C280 My First Mercedes-Benz... (155k miles. EXCEPTIONAL AUTOMOBILE. Was Very hard to let go of!)

1 bar oil pressure at idle is good. You should hit 3 bar once the rpms get around 1,500. Sounds to me like your oil pressure is fine.

Rough idle. My experience points to spark plugs and their gap. A gap of .040 idles smoother than .032 in my case. Ensure that spark plugs wires are secured. You may need to take a look at the condition of the rotor and distributor cap.

Then of course there's the FUEL side of the equation and the possibilities there are endless.

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Mike Murrell
1991 300-SEL - Model 126
M103 - SOHC
"Fräulein"