20w50 and 5w30 users - PeachParts Mercedes-Benz Forum

winmutt · #1 01-16-2009, 03:54 PM

Should all be shot. Flame suit on.

Neither of these are rated for diesels (that I have EVER seen), don't use them!

oldsinner111 · #2 01-16-2009, 03:56 PM

I agree.

pawoSD · #3 01-16-2009, 04:03 PM

As do I. With so many proper weight diesel oils out there, there's no reason to use the wrong stuff. (and I bet tons of people do)

babymog · #4 01-16-2009, 04:04 PM

Oh goody, an oil thread. Does this include syn as well as dino?

turbobenz · #5 01-16-2009, 04:05 PM

I agree !

71inka02 · #6 01-16-2009, 04:06 PM

Quote:

Originally Posted by babymog

Oh goody, an oil thread. Does this include syn as well as dino?

Hopefully it will also include brands, and the best places to buy......

pawoSD · #7 01-16-2009, 04:11 PM

Quote:

Originally Posted by 71inka02

Hopefully it will also include brands, and the best places to buy......

And in depth arguments about particulates trapped in the oil.......and how expensive oil analysis results prove one brand is 1% better than another!

pawoSD · #8 01-16-2009, 04:29 PM

Quote:

Originally Posted by 84500SEL

well then shoot me. i got 2 240d's . one that got a rebuilt motor, that cranks up fine at 28 deg ,the other car has 225k on it ,and dont start in 28 deg weather both have 20x50 gtx in them

you telling me that if a change over to whatever you tell me to it will crank up ??

if not, will you pay for my oil change then ?

Its for sure not good for the engine to force thick cold oil like that through it. It could starve critical areas for needed oil/lubrication. Not to mention it puts a much higher load on the starter....

I doubt 20x50 gtx is even a diesel rated oil. Why would you run a non-diesel oil?

pawoSD · #9 01-16-2009, 04:58 PM

Quote:

Originally Posted by 84500SEL

im not going to name the shop but they put 20x50 in older diesels
when i was at the dealer in 84 they used to run straight 30wt Q/S ???

what a cheap diesel oil i can put in it ,it never gets colder than 28 deg where iam at.

non syn. oil > what to get ? brand and weight ,this car is for sale need it to start in 28 deg weather. starts in 32 deg after 2 long glows and another 15 sec, then hit key till it shakes to a start...at 28 deg, no go!! bwttery gets down before it starts. i got a bad block heater on it

28F is pretty cold, why not use a synthetic?

If not though, I'd use a 15w40 dino diesel oil. Shell Rotella, Valvoline Blue.....Mobil 1300......Delo 400.....there's a bunch of them. Just check out the diesel oils at your local Autozone/Napa....there's tons.

With synthetic it'd probably start way easier in the cold. Mine has been running synthetic for over 55,000 miles and it starts better than ever. Fired up in about 4 seconds today with one short glow when it was -2F out, with no block heater!

rrgrassi · #10 01-16-2009, 05:50 PM

The diesel oil has additives that suspend soot particles, the gasser engine oils do not.

If you change the oil and filter say every 1000-1500 miles, then use the gasser oil. Also the diesel engine exerts more shear pressures on the piston's wrist pin, connecting rods, rod bearings, main bearongs and crank shaft. The gasser oil does not stand up to that very well for a long period of time.

tyl604 · #11 01-16-2009, 05:58 PM

I used to use 5w30 in my '81 300SD to help it start in cold weather. Then I found out that I needed to adjust my valves after 235,000 miles and it starts perfectly now. Started first crank at 12 degrees in Atlanta this morning. So no longer need the out of spec oil. But it did help for two or three years. Of course did not use it in warm weather.

babyjames · #12 01-16-2009, 07:26 PM

15w40 is not, necessarily, the oil recommended by MB. Check the chart in the owner's manual or the FSM. Different viscosity oils are recommended for different temps. You can safely go thinner in the winter, and thicker in summer.

Were diesel-specific motor oils even available when these cars were new? An honest question....

Jay.