After driving for 15 min. or so w/ the engine up to temp, I have noticed that the top of my oil cooler is barely warm to the touch while the bottom is quite hot. Does this indicate a major blockage developing? If so will oil still circulate properly(just not cool well)?

The car is driven regularly and does not need to have oil added between changes. I have good oil pressure(about 1.75 bar when hot).

Mark

__________________
85 300D (California) 220k
03 Silverado 1500 Xcab Z-71 Guzzler 90k Real American steel(made in Canada)
03 Suburban 1500 4x2 Guzzler 170k Real American steel(made in Mexico)
Diamondback hybrid
Element skateboard(mileage unknown)

Good news for diesel owners...There's no such thing as cold...only the absence of heat!

"Beer is proof that God wants us to be Happy." Benjamin Franklin

"Possession....the King of sin." The Avett Brothers

At speed, (2500 R.P.M.+) you should have 3 bar.

The oil temp thermostat, in the filter housing, opens at about 110C (oil temp not coolant temp). Idling for 15 minutes is not going to cause that to happen.

__________________
Sam

84 300SD 350K+ miles ( Blue Belle )

Depending on ambient air temps and how hard the engine is working, the oil thermostat may not even open. The difference in temperature you are feeling on the oil cooler may be due to heat transmitted up the pipe from the engine or from air circulation.

__________________

"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

Sorry, I meant to type "1.75 bar at hot idle". I do have 3 bar as soon as my foot is on the pedal.

Mark

__________________
85 300D (California) 220k
03 Silverado 1500 Xcab Z-71 Guzzler 90k Real American steel(made in Canada)
03 Suburban 1500 4x2 Guzzler 170k Real American steel(made in Mexico)
Diamondback hybrid
Element skateboard(mileage unknown)

Good news for diesel owners...There's no such thing as cold...only the absence of heat!

"Beer is proof that God wants us to be Happy." Benjamin Franklin

"Possession....the King of sin." The Avett Brothers

I wouldn't expect to get very hot oil after idling. I'm talking about 15 min. at 50-60 mph.

Thanks,
Mark

__________________
85 300D (California) 220k
03 Silverado 1500 Xcab Z-71 Guzzler 90k Real American steel(made in Canada)
03 Suburban 1500 4x2 Guzzler 170k Real American steel(made in Mexico)
Diamondback hybrid
Element skateboard(mileage unknown)

Good news for diesel owners...There's no such thing as cold...only the absence of heat!

"Beer is proof that God wants us to be Happy." Benjamin Franklin

"Possession....the King of sin." The Avett Brothers

I had to see if this thing was blocked or not. With the engine already up to temp., I hit the highway(I don't do that very often with this car). It was about 75 deg. here today and I did about 10-15 miles on the highway at 80+mph. When I stopped the oil cooler was hot top to bottom. I didn't think it would take that much to get the oil tstat open, but it seems to be fine. Thanks all for your input.

Mark

__________________
85 300D (California) 220k
03 Silverado 1500 Xcab Z-71 Guzzler 90k Real American steel(made in Canada)
03 Suburban 1500 4x2 Guzzler 170k Real American steel(made in Mexico)
Diamondback hybrid
Element skateboard(mileage unknown)

Good news for diesel owners...There's no such thing as cold...only the absence of heat!

"Beer is proof that God wants us to be Happy." Benjamin Franklin

"Possession....the King of sin." The Avett Brothers

Actually the thermostat for the oil cooler begins to open @ 95C, (300D NA)

http://rbk3.com/mbz/tsm/MBZ18-120%20OIL%20THERMO.pdf


its fully open @ 110C

__________________
Cheers,
Robert