240D owners: What's your oil pressure at idle?

[DieselAddict]

Mine has always been pretty high. The oil pressure gauge is pegged at 3 bar for quite a while after a cold start until the engine is totally warmed up at which point the gauge would typically be at 2.5 bar which still seems pretty high compared to the 300D's that I used to have (those would usually show 1.5 bar). Only after a long freeway drive does it drop to 2 bar. I was wondering about the elusive oil cooler thermostat, but after doing some research I have the impression that only the turbo models have them, but I'm not sure. If my car has it it would seem that it's stuck open, resulting in cooler oil and higher oil pressure reading. But before I tear into the oil filter housing, I want to check with other 240D owners to see what kind of oil pressure is typical for this engine.

[Brian Carlton]

I can't give you any advice on the 616 but I'll tell you a story on the 617.

The SD always ran oil pressure of about 1.6 when fully warmed up.

After the head was redone and all the exhaust valves were replaced and the guides were replaced, the engine now runs 2.1 at idle when fully warmed up.

I can't fathom how it picks up .5 bar due to valves and guides but the evidence is incontrovertible.

It also starts at 12°F. within 1 second without a block heater. Related????

[mbzkid]

Barely off the bottom peg. It comes up to 3 bar as the engine speed increases. Sometimes it is a bit higher when cold.

Been that way since day one.

[apache]

Pegged at cold idle. 1 bar or slightly less at hot idle while stopped in gear (auto). Pegs at any higher rpm.

[bgkast]

Peged at 45 psi when cold, 30 psi when fully warmed up. I am using Mobil1 5W40 oil.

[DieselAddict]

Now that I think of it this may be a rather subjective poll. The readings will also depend on the idle speed and type of oil used. But let's keep them coming anyway. The manual states 0.5 bar is the bare minimum and frankly I'd worry about anything below 1 bar at any idle speed.

I use Mobil 1 5W-40 with 20% Lucas Oil Stabilizer which does tend to raise the oil pressure a bit. Tonight when I got home in the 240D I touched the oil cooler and the metal lines that go in and out of it. The cooler was cool to the touch as was the output line and the input line was pretty warm, but not hot. The oil pan, on the other hand, was very hot as it's supposed to be. So it doesn't seem like the oil cooler thermostat, if there is one, is stuck open. I guess I just have a really strong oil pump and engine.

[Big J]

When mine is cold, it pegs at 3 bars( idle or driving). when I'm driving, 3 bars. At idle, when hot, in gear, 2 bars. At idle, when hot, in park, 2.5 bars.

[airbus]

At idle pegged when cold, 30psi when warmed up. That's what mine does (and your's too, aparently) and I think that's pretty much where it should be. Better slightly too high than too low.

[Angel]

1982 240D, when fully warmed and idling forever, Idle oil pressure is between 1.5 and 2.0bar (22 to 30psi).
My mother has an AT 240D, and her idle is higher than mine, so she never sees oil less than 2 or 2.5 bar.
I'm not sure if all of them do, but all the 240D's I've seen have the little "idle adjuster knob" on the dash - the black knob you turn to raise or lower idle - really helps cold stars on mine. If this contraption breaks, your idle will be set where the knob was last set- and since none of our 240D's have tachometers (from the factory at least...) its tough to know where your car is idling... It doesnt take a lot of rpms to raise oil P from 1.5 to 2.5 bar....

-John

[gatorblue92]

mine is pegged at cold idle and slightly lower after its warmed up

[t walgamuth]

if you leave off the lucas next oil change your pressure will drop.

though i dont know of any harm in it i never run anything except oil unless i am chasing a problem.

tom w

[iNeon]

my shlomo runs at 1.5-2 bars at hot idle, in gear; a bit on the lower side if its one of those redlights RIGHT off of the interstate

its pegged at hot idle in park/neutral and even cold idle as well, since i have the idle adjust knob and use that in the mornings.

these real gauges freak newbies out, dont they? my father swore my oil pump was going out because it moves around-- says it should hold a constant pressure--

i told him hes been driving a modern car with dampened gauges too long-- that theyre not even gauges, theyre expensive dummy lights that pretend theyre gauges.

but alas-- the child can impart no knowledge on the elder in my household

[bennett]

pegged at idle.... I use delo 400 15/40w

[DieselAddict]

Originally Posted by Angel

I'm not sure if all of them do, but all the 240D's I've seen have the little "idle adjuster knob" on the dash - the black knob you turn to raise or lower idle - really helps cold stars on mine. If this contraption breaks, your idle will be set where the knob was last set- and since none of our 240D's have tachometers (from the factory at least...) its tough to know where your car is idling... It doesnt take a lot of rpms to raise oil P from 1.5 to 2.5 bar....
-John

Yeah as far as I know all 240D's and non-turbo 300D's have the idle adjust knob. I definitely use it before I start the engine cold and then I turn it back down as the engine warms up. I agree without tachometers it's a bit difficult to be objective here. I adjusted my idle at the IP by listening to the engine and tried to set it to about what my old 300D sounded like at 750 RPM.

Originally Posted by Angel

if you leave off the lucas next oil change your pressure will drop.

though i dont know of any harm in it i never run anything except oil unless i am chasing a problem.

tom w

Actually Lucas doesn't make that much difference in oil pressure. It's about the same that it was when I was using pure Delo 400 or Mobil1 15W-50.

[pj67coll]

81 240D stick.

When running with any throttle pegs at 3. When idling between 2 and 2.5 depending on the temperature. Engine was rebuilt 190000 miles ago. No oil leaks, no smoke. So I guess it's in pretty good shape.

- Peter.