I’m not interested in any other engines at this time. Please only post if you have data from your OM603

Poll criteria: level or near level highway travel between 65-75 mph with ambient temperature under 70(°F) and no A/C

List any pertinent data in your post. Below is mine.


1987 300TD with 265,xxx #22 head


80-85(°C) on flat highway cruising at 65-75 mph, it will go up to 90(°C) when climbing, but will return to 80-85(°C) when descending or leveling off
85(°C) around town


up to 110(°C) climbing from 2,000 ft. to 6,5000 ft. at 70-80(°F)


Radiator is a 7 years old Nissens


water pump is 6 years old


fan clutch is 3 years old


new coolant within the last year

__________________
1987 300TD 309, xxx 2.8.2014 10,000 mile OCI


Be careful of the toes you step on today, as they may be connected to the ass you have to kiss tomorrow. anonymous

“Be who you are and say what you feel, because those who mind don’t matter, and those who matter won’t mind.” Dr. Seuss

I'm not sure that the poll is correct as no variables are listed. I voted for 80-85 but this temperature is only applicable on level ground without a/c and with ambients that are typically about 70°F.

Add 80-85° ambients and a/c and the vehicle will start to run about 90°C.

Add upgrade and the vehicle will begin to crowd 100°C.

Add 95° ambients and a seven mile upgrade and speeds of 65-70 mph and the vehicle will push 102°C.

So, it's all dependent on the variables...............

Agreed. I added some more specific criteria.
Having owned an OM603 powered car for 6.5 years, I pretty sure that with a properly sorted cooling system the engine is designed to run at or near 80°C when the engine isn't under load.
There are so many threads on here about overheating OM603s that I just want to establish a baseline temperature for the average OM603 whether it is in a 124 or a 126.

Mine will actually see 110 given your last set of variables. I have the 100/110 switch in it so at that point the A/C is off which is fine with me.

__________________
1987 300TD 309, xxx 2.8.2014 10,000 mile OCI


Be careful of the toes you step on today, as they may be connected to the ass you have to kiss tomorrow. anonymous

“Be who you are and say what you feel, because those who mind don’t matter, and those who matter won’t mind.” Dr. Seuss

I see plenty of threads about the drivers who own the 603 getting overheated. I've yet to see a single thread where the actual 603 engine overheated (with the proviso that the belt and water pump remained functional and the engine didn't run out of coolant).

Yes and you will never run out of fuel if you keep filling the tank up. Obviously (at least to me) the car will never over heat if every component of the cooling system is kept up, but that's not always the case or all those engines would still have #14 heads on them.

What I'm trying to achieve as aaa pointed out is a baseline for other folks with these engines that don't have all their cooling components in working order. If you are seeing 95-100°C in conditions where most others are running at 80-85°C, then you might want to sort that out before you head over Loveland Pass with the A/C set at 65°F!

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1987 300TD 309, xxx 2.8.2014 10,000 mile OCI


Be careful of the toes you step on today, as they may be connected to the ass you have to kiss tomorrow. anonymous

“Be who you are and say what you feel, because those who mind don’t matter, and those who matter won’t mind.” Dr. Seuss

I'd like to find just ONE OM603 that actually overheated from the exact conditions that you describe above. Again, with the proviso that the belt is intact and the coolant level is maintained.

If I read the temperature gauge correctly, the red zone is 120C. So any temperature below 120C is acceptable to me, though I get nervous when it gets to 115C so I install a manual override to turn on the Aux fan.

It is not a perfect world and this is not rocket science. I really do not know what you try to achieve.

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Not MBZ nor A/C trained professional but a die-hard DIY and green engineer. Use the info at your own peril. Picked up 2 Infractions because of disagreements. NOW reversed.

W124 Keyless remote, PM for details. http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/334620-fs-w124-chasis-keyless-remote-%2450-shipped.html

1 X 2006 CDI
1 x 87 300SDL
1 x 87 300D
1 x 87 300TDT wagon
1 x 83 300D
1 x 84 190D ( 5 sp ) - All R134 converted + keyless entry.

At 110°C my electric fan makes little to no difference. The only thing I find it useful for is to keep the A/C cold while idling or at very slow speeds.

__________________
1987 300TD 309, xxx 2.8.2014 10,000 mile OCI


Be careful of the toes you step on today, as they may be connected to the ass you have to kiss tomorrow. anonymous

“Be who you are and say what you feel, because those who mind don’t matter, and those who matter won’t mind.” Dr. Seuss

What you accomplish is knowing that your cooling system is working properly. If you see 115c in not-that-extreme conditions, then there are more extreme conditions that you risk coming across that will damage your engine. When you know what the normal range is, you hopefully will notice problems ahead of time, and resolve them before they become too serious.

I think I Got it.

I would not be driving the car if I see 115C during day to day freeway driving.

__________________
Not MBZ nor A/C trained professional but a die-hard DIY and green engineer. Use the info at your own peril. Picked up 2 Infractions because of disagreements. NOW reversed.

W124 Keyless remote, PM for details. http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/334620-fs-w124-chasis-keyless-remote-%2450-shipped.html

1 X 2006 CDI
1 x 87 300SDL
1 x 87 300D
1 x 87 300TDT wagon
1 x 83 300D
1 x 84 190D ( 5 sp ) - All R134 converted + keyless entry.

'87 300d, the crappy head, 123k miles.

The gauge goes to 90 and never budges, no matter what.

A/c works, I've only had it for 15k miles and haven't touched the cooling system. I drive it hard, cruising at 85mph and run WATF.

Does not matter with my temperature. my car sits at just over 80*c and sits there unless it is VERY warm outside then it goes closer to 84ish

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hum.....
1987 300TD 311,000M Stolen. Presumed destroyed

So 84°C is the highest temp you've ever seen even with the A/C on and over 90°F ambient? If that is the case I would say your cooling system is in great shape.

__________________
1987 300TD 309, xxx 2.8.2014 10,000 mile OCI


Be careful of the toes you step on today, as they may be connected to the ass you have to kiss tomorrow. anonymous

“Be who you are and say what you feel, because those who mind don’t matter, and those who matter won’t mind.” Dr. Seuss

both before and after I had my radiator replaced (Diddnt need to be replaced... there was an incident and my old Rad popped....)

Other then the injection pump crapping out it's been a great car

__________________
hum.....
1987 300TD 311,000M Stolen. Presumed destroyed

... my 87TD sits almost dead on 90 all the time unless I'm running the a/c in stop and go. I've got the #14, and the original single large diameter aux fan.
I've replaced the fan clutch, and the belt tensioner very recently.

__________________
John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 560SL convertible
1987 190D 2.5-5SPEED!!!

1987 300TD
2005 Dodge Sprinter 2500 158"WB
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!