Curious, what's your average coolant temp?

Mine has been creeping into the ~95°C area recently sitting at idle for about 5-7min. Ambients around 95°F and 95% humidity. Cruise temps are about 90°C and freeway seem to drop back to around 85°C.

This seem normal or is something amiss? The fan clutch is working fine and it's new within the last nine months or so. Just flushed coolant at same time new thermostat went in. I didn't remove the rad to clean the fins (silly I know)

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I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]

"Normal" for some is abnormal for others.

A brand new radiator and a clean cooling system, with an operating fan clutch will keep the temps below 95°C. under just about any condition.

The '86 probably has a fan clutch that doesn't work properly and a radiator that is not perfect and it runs up to 98° on just about every accel using heavy boost. It's peaked at about 105° on a 7 mile upgrade holding 65mph.

None of these temps is worth discussion as a problem.

Well as long as nothing bad will happen, it's okay.

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I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]

.........nothing bad will happen........

Mine never really goes above 90C. Unless its a hot day and I'm using the AC or I'm doing WOT runs. Normaly it stays just a tick over 80C.

Heck I was running 110 last night for awhile and the temp was only slightly higher then normal, 85Cish.

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1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

Your temps sound just like mine. (It's kinda scary actually).

--Matt

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KI6CCA

Current Stable:
1987 300SDL
1980 450SEL

Out to Pasture:
1982 300D KIA (Rice Rocket vs. 123: He hit me at 80-100MPH I walked away he went to the hospital. Sounds fair to me!)
1985 300D EURO Scrapped (got more money from state than car was worth)
1979 & 1980 300SD Great Cars!

Mine stays pretty low, but for some reason the aux fan stays on all the time, which is fine with me if it keeps the engine cooler.

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87 300D - Running on Veggie oil; 260,000 plus miles; Original #14 head

Mine hangs out at about 82-85 most of the time. In normal weather, on a climb, it goes up to 90 ... on a big climb, it goes up to 100 ... on a HUGE climb (mountain of doom) it goes up to 105. In HOT weather, it hangs out between 85-90, sometimes dropping lower when coasting downhill. On climbs, it will go to 100 ...very rarely higher. On the hottest day of this year, while in stop-n-go traffic in the city for a long time, it went up to just above 100 ... went right back to 90 when I got it on open road. Highest it's ever been is 110 ... that was on the big, long mountain when it was 105 F ambient temp ... and it went back down fast on the huge downhill that follows the uphill.

So there's my detailed report. Interestingly, despite the fact that it's been a much hotter summer this year than last, my car has been staying a little cooler ... maybe it has to do with altitude ... I moved from central PA to Delaware, a very low state.

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1987 300D, arctic white/palomino--314,000 miles
1978 240D 4-speed, Euro Delivery, light ivory/bamboo--370,000 miles
2005 Jeep Liberty CRD Limited, light khaki/slate--140,000 miles
2018 Chevy Cruze diesel, 6-speed manual, satin steel metallic/kalahari--19,000 miles
1982 Peugeot 505 diesel, 4-speed manual, blue/blue, 130,000 miles
1995 S320, black/parchment--34,000 miles (Dad's car)

my 90 350sdl runs around 80 mostly.

when i bought it it ran around 60. and everything was horribly filthy with dirty crusty oily stuff. the intake, inside the valve covers etc. i replaced the tstat right away. it is gradually purging itself of all the crud.

tom w

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Mine usually runs between 80-100. Lately its been so hot in Atlanta, with the AC on sitting on the downtown connector (ie, blast furnace) in rush hour traffic its hit 115-120C

Once I get moving it drops to 100 or so. Not leaking any coolant, running very well. Just dont like it getting quite so hot...

250k miles, 1987 300d turbo.

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Paul
Benz-less
I need an SDL !

Here in the desert we switch the AC on in May and just leave it on till September. With avg daily temps over 100 degrees F and AC running steadily my 603 runs at 100C in town. The radiator is now 10 years old. MB coolant, clutch & fan two years old, T-stat two years old. I could swear it used to run at 95C in past summers, but I could be mistaken. Also, we hit highs of 109 last week.

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Brian
87 300Dturbo 180K #14 head still running R-12 SOLD 12/2017
02 F350 Powerstroke 180K
05 Chevy Express 1 ton w/Royal Utility box 120K
08 Infiniti FX-35 40K
15 Golf Sportwagen TDI 35K
10 Sprinter 3500 chassis with a Class A Winnebago on it. 56K

mines been right at about 90c give or take.

Anyone think coolant temps might have to do with aux coolant pump (if so equipped) ? My 87 300D turbo has one under the washer res and, like everythign else, its a fossil. I wonder if it even works, or if it would have effect on coolant temps?

Anyone know how to test it?

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Paul
Benz-less
I need an SDL !

I don't. That's for the heater core as I recall...

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I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]

Spent the day tinkering with the '87. ALDA adjustment. Trans vacuum adjustment. Just getting an "understanding" with the vehicle.

Did some high power runs to check shift points.......way too early.

The point?

The temperature gauge sat at 88°C. and never budged..........at idle........at full power.........not a whisker of movement..........which I found to be quite amazing.

My conclusion?

A brand new radiator.