oil pressure gauge "pulsates"
 

240d. noticed the other day at engine idle the oil pressure guage was pulsating, i.e. was moving around the two bar mark at 2 - 4 hz rate my guess 5 psi or so. this phenonenon lasted the better part of the day and then suddenly stopped. what could possible cause such an occurance?

I think its normal, nothing to worry about.

In hot weather, the oil pressure gauge on my 300SD would sometimes pulsate as you mentioned. What grade of oil do you run in your car? I always use 10W-40 petroleum based in my cars.

aaron, the 83 is a replacement for a 79 that i lost. that was stinky. seriously, the temperature here yesterday was 40 -45 degrees f. driven mb diesels now about 50k miles. never saw this pulsating before. as new purchase, i changed oil and filter. used the usual 15w -40 dino rotella. (fuel filters and valve adjust for completeness of proceedures done by me).

Fixed many pulsating pressure gauges with new o-rings on the end of oil filter housing top piece (small o-rings). Try it and see if this helps.:D

my whole car (240D) pulsates :)