83 240D Oil Pressure Question - Page 3 - PeachParts Mercedes-Benz Forum

shertex · #31 11-27-2012, 07:31 AM

Quote:

Originally Posted by t walgamuth

I certainly would not run a 240 7500 miles on any oil let alone one which is really not correct for the engine.

Neither would I....but the guy does do oil analysis for a living, so I thought it was an opinion worth posting.

Stretch · #32 11-27-2012, 07:35 AM

I think the oil analysis guy is used to modern petrol engines rather than diesel ones. If you took the oil in to him after 100 miles and told him you'd just done 5000 miles he'd probably believe you!

Stretch · #33 11-27-2012, 07:38 AM

Quote:

Originally Posted by shertex

...

Army, I will say that your point about not trusting others with oil changes is well taken. When I removed the filter, the o-ring seemed to be more compressed than I would have expected....suggesting to me that PO did not change the filter (though he says he THINKS he did).

...

As we all know this forum is famous for its oil threads - but it is also a place of several "the oil change got messed up" threads...

...changing the oil might seem simple to most of us; but for some somethings are never easy enough - that's why I'm paranoid about things like that!

No offence meant to the previous owner of any car - but I just don't trust you.

Air&Road · #34 11-27-2012, 11:31 AM

Quote:

Originally Posted by shertex

My inclination is not to worry about it....unless there's some clear reason why I should.

Army, I will say that your point about not trusting others with oil changes is well taken. When I removed the filter, the o-ring seemed to be more compressed than I would have expected....suggesting to me that PO did not change the filter (though he says he THINKS he did).

Also, FWIW, I asked one of the techs at the outfit that does my oil analysis about the M1 0w40....he said "I would let it go for awhile. The VI improvers are very good and the additive package is aggressive on the Mobil 1 products. Since it is a gasoline engine oil, I would probably drain at 7500 miles though."

Before I stand fast on my agreement with this, I would like to actually watch it, but I think this is the best approach. The gauge does go to zero when you cut off the engine doesn't it?

If so, I think you should drive it and be happy.

mopar65pa · #35 03-10-2013, 07:10 PM

I just got my 82 300TD running after an engine swap. I put an after market gauge on it because the factory one was pegged all the time. I thought that it was reading wrong.

I have since found out that the after market gauge is reading 85psi cold at an idle, and 95 at highway speeds till it warms up. Then it will read 60psi at an idle and 80 psi at highway speeds.

After reading two of these threads I'm thinking this is normal. But I sure didn't when I fired it up.

Oh BTW the old beat broken engine was pushing 3bars on the factory gauge too......

barry12345 · #36 03-10-2013, 10:19 PM

Try to find the spec for the pressure the relief valve on the oil pump opens. Your situation may be normal.

As for oil threads they are notorious.These older indirect diesel engine get a lot of soot in the oil. It is certainly not good. As the percentage increases with usage it is even worse.

I would expect the same amount of soot is in the oil regardless of the type of oil. Doubling the change interval will make twice as much soot present as there was at half the milage. If it starts to clump up it becomes even more abrasive in nature.

My honest guess is that either type of oil should be change out at the same milage interval. Our use of synthetic should be based on the lower friction when starting and reduced starter wear etc as the reason for the higher cost rather than changing the length of service. One can use oil testing to verify their beliefs a couple of times.