Operating Temp for OM617

[404zero]

What is the ideal operating temp for a OM617?
The mechanical cooling fan decided that it didn't want to be on the truck.
I'm not sure how it broke off but it was just laying on the cross member of the truck the other day, all 4 bolts sheered off.
So I decided to install an electrical fan.
The flex lite fan I installed pulls 3100 CFM.
I drove into work this morning and low RPM's the temp was a straight 180*F maybe even a little lower.
At high RPM's the engine would go to +- 195*F.
I think that is a bit to hot but any thoughts....

Thanks.

[toomany MBZ]

80 to 95 C. Can't help with F.

[pawoSD]

About 175 to 205 F is the ideal temp.

180 running normal and 195 under load are perfect temps.

[404zero]

Thanks for the replies. Im glad the temps are in range for now. But those water temps are when it was 32*F outside. I am a little nervious for the summer... Being new to this motor, how do they handle heat in the summer?

[sd300td]

Mine will reach 110 C in the summer months, under heavy load i.e. climbing through a mountain pass in SoCal on the way to Vegas. It'll usually sit at 80 C under normal driving.

[pawoSD]

Originally Posted by sd300td

Mine will reach 110 C in the summer months, under heavy load i.e. climbing through a mountain pass in SoCal on the way to Vegas. It'll usually sit at 80 C under normal driving.

Thats too hot. You probably need your radiator cleaned or replaced. When its 90F out and I run mine hard I can barely get it over 88-90C. With my old radiator it would climb to 110 like yours does.

[80's old school]

Originally Posted by toomany MBZ

80 to 95 C. Can't help with F.

If anyone wants to convert C to F. Take deg. C times 1.8 then add 32.

If you wanna go from F. to C. Take deg. F minus 32 and divide by 1.8.

Piece of cake!!!

[oldsinner111]

No Both my vehicles will do all year with stock thermos.Its just in Summer I carry more heavy loads,and do not want to tax my heat range.

[mobetta]

if all 4 bolts sheared, then what is turning the water pump??

[oldsinner111]

I run stock thermostat for Fall thru Spring.In summer I have one with 5 holes drilled in it,for mountain high speed driving.Both Benz,and Toyota.

Originally Posted by oldsinner111

In summer I have one with 5 holes drilled in it,for mountain high speed driving.Both Benz,and Toyota.

Thats very bad. If you have to mutilate the thermostat just for it to cool better then you definitely need to clean or replace the radiator.

[404zero]

Originally Posted by mobetta

if all 4 bolts sheared, then what is turning the water pump??

My OM617 is in a Unimog and has been customized a bit I guess. The fan was extended out with the spacer in the picture. It was mounted straight out of the crank. Here is the broken bolt and spacer picture...



I will try to take a picture of what it was mounted on. There was no belt for a water pump so I assume it was moved...I don't know. No you have my interested. I will have to go check it out...

[diesel123dan]

I run mine triggered at about 80*C, that's 175*F. Hasn't given me any trouble during the 115* summers in SoCal. Enjoy the extra horsepower!

[jt20]

I know plenty of people that take their thermostats completely out during summer... but thats only on gas engines.

Your diesel will drop in fuel efficiency if you are running too cool. ie.. heavily modifying your thermostat or removing it.

[oldsinner111]

Oh yeah I watch temps.