Mercedes products have been in my family for decades and decades. Vehicles ranging from 200D, 220D, 240D, 300D, 300CD, 300E, E320, 400E, 420SEL, 300SDL, and 560SEL.
I have never - EVER - heard of any Mercedes experiencing issues with oil pressure. This is not to say that it does not happen, but I do believe that the mechanical gauge causes far more worry than prevented issues.
Your ears will tell you more than that damned gauge if you are having oil pressure issues.
Now the coolant temp gauge on the other hand.... that one does deserve close watching.
__________________
Matt in Atlanta
1983 300CD
Black-on-black daily driver
270K and still chugging along
1992 400E
Smoke silver-on-mushroom
145K and counting on the M119
the engine has no problems with it or any noise coming from it sometimes when its really cold when it starts up for the first time u can hear vales tick for like sec or 2 then it stops but every w124 that i heard start in cold times does this even some new cars in. but in wormer time u won't hear nothing i will be replacing my oil soon and my oil filter and i will go with mobil1 20-50 its expensive but its worth it tx for the help guys i got few more bugs to sort out and il be problem free i hope ?? hehe
As a follow-up to my post, I say I've never seen nor heard of sudden loss of oil pressure on any MB engine. Then I go to the W123 page and see a case of oil pump failure!!
So it does happen, but that is the ONLY case I have ever heard.
benznawz - is there a reason you want to run 20W-50? That oil is incredibly heavy - the only motor I'd run that in is a 617 and even then only if you could find a Diesel rated 20W-50. That is a damned heavy oil, especially in winter.
mrhills0146 well i always have thought thicker oil more protection at higher revs and higher temps im i
wrong? but i will be using 10-30 mobil1 for the winter and go with 20-50 in the summer good idea or bad? or should i go with 10-40 in summer? i just got the w124 bible book and it has tons of good info on my problems like hesitations when cold or when worm and from stand still it has lil hesitations between 1000rpm and 1500rpm and hard cold starts its a really good book i recommend it to every w124 owner il be doing work on the engine and will post some pics as the progress goes and as for my rear suspension noise i found what it is its the big control arm that hold the susp and the bolts ware loose simple fix
No idea what type of vehicle you are working with. 300E? E320? 400E? E420? Roughly where do you live? Climate CAN influence your choice of oil.
My opinion? Best oil for a gasser is M1 5W-40. Depending on the mileage you drive, you can run that oil and change it 2x per year (that is what I do in my 400E.)
If you have an M119 and run 20W-50 in it, I can almost guarantee that you'll have a nice lifter tick. That oil is too heavy for that motor.
In reply to mrhills assertion that you will 'almost guarantee' (d) have a lifter tick with 20-50.......
In my quest to find the right oil for me, I have 20-50 dino oil in my 05 E420 M119 without any issues (that I know of). That said, I'm dropping back to a 40W for the next oil change.
I began my oil weight odyssey when the gauge would not show above .5 bar in Atlanta summer heat... wanted to know was it the oil pump or what...using Mobil1 10-30.
I suspect it is your oil pressure sending unit. A very easy DIY job and not expensive. It screws on and is located on the back side of the the oil filter block toward the firewall. Single wire lead on it. Look behind and below the oil filter and you'll see it.
Good Luck,
Jayare
Whats the cost on the sending unit? I could have that done with my oil change right?