I have an 89 190E 2.6 Is the six-cylinder engine in it a 103? I read an early comment by Andre in reference to putting in Bosch Platinum spark plugs.

I replaced mine with the same a week ago and have been experiencing serious sluggishness during idle and low rpms. I thought it was the gas I'd switched to (Chevron). I'm trying to determine if the engine is the same (300E in a 190E 2.6) and if the plugs could be my problem.

The plugs I replaced, which were also Platinums, showed no oil residue.

If the engine is a 103 I assume the same rule applies to use regular copper core spark plugs. Thanx.