Recently I had my mechanic replace all of the tubing that connects to dreaded servo on my w116 diesel.

Since I’ve had the car back its running very hot almost into the red. Even in below freezing temps. I addressed this with the mechanic and he couldn’t find the problem.

Prior to having the tubing replaced engine temp was NEVER an issue.

What did he do that is causing this issue?

Thanks!!

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1973 280 - Sold
1980 300SD - Sold
1982 240D - Stolen
1988 300E - Sold
1989 260E - Sold
1989 560SEL
1994 E420 - Sold
1997 E420
2005 CL500

i would check the coolant level.. then the thermostat

__________________
-Trevor

OBK #12
1980 300SD 333,XXX miles - Totaled
1986 Mazda RX-7 212,XXX miles - impounded and auctioned off
2005 Jeep Liberty CRD Limited 33,000- SEGR, Provent, Fumoto

was the servo removed or bypassed?

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michael cole 1980 300SD gone now but not forgotten,87tdt,90 300te 4matic 95 e320 wagon

no the servo wasnt removed or bypassed. it was bypassed in the past but not any longer. all I had the shop do was replace the hosing that attaced to the servo.

__________________
1973 280 - Sold
1980 300SD - Sold
1982 240D - Stolen
1988 300E - Sold
1989 260E - Sold
1989 560SEL
1994 E420 - Sold
1997 E420
2005 CL500

did your tech pressure flush the cooling system after the repair?

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michael cole 1980 300SD gone now but not forgotten,87tdt,90 300te 4matic 95 e320 wagon

no he sure didn't. that's what i get for trying to save a few bucks. since he didn't pressure flush it what is causing the problem? air in the system?

__________________
1973 280 - Sold
1980 300SD - Sold
1982 240D - Stolen
1988 300E - Sold
1989 260E - Sold
1989 560SEL
1994 E420 - Sold
1997 E420
2005 CL500

Almost certainly air in the system. Point the car uphill, run the engine for a while with the heater on full blast and it should burp the air. Recently a forum member had a problem burping because the overflow hose to the expansion tank was plugged.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

When burping the air out, I'd rev the engine up a bit to increase the flow. 2k rpm is probably enough. I agree the temp issue is likely due to air in the system.

__________________
-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

Mine is now running hotter than normal.
It's usually right at 80C but yesterday and today the needle is around 90-92-ish.
I crank the defrost so it doesn't go further and open the sunroof (heat is hot, today is 55degrees) so I don't boil, but what could be causing this now?
Checked coolant level and oil last night, all is proper.
Now that the amp got replaced I have great heat.
Could my tstat on the 116 be going bad now?
Thanks!

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Ginny in Denver-ish
78 300SD, 265K (mine)

Mine has always run warmer that 80c when the weather is warm. It's fine in the winter.
I've replaced the thermostat and put in a new (recored) radiator and it still runs 90 to 95 or even higher when it really gets cookin down here. I'm beginning to think about replacing the water pump.

__________________
Joe

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1980 300SD - 495k miles - 'The Ambassador'
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Former Family Members
95 C280
73 280SEL
90 300D
87 300SDL (X2)
86 560SEL
84 300D
80 300SD

I replaced my t-stat a few months ago and now my car runs around 88-90C on the freeway, never higher....and around 85-86C in the city. Outside temp doesn't seem to matter....but it has not been above 35F since I replaced it....in fact its only 14F right now....so we'll see this summer what it does.


My guess is your t-stat may be sticking, or the temp sender on the engine might be going bad. I am going to replace mine the next time I place a parts order.

__________________
-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

I'm wondering if my water pump isn't pushing the volume it's supposed to.

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Ginny in Denver-ish
78 300SD, 265K (mine)

Yep and the dreaded w116 servo is high point in the line, can create massive air bubble there slowing coolant flow. Heck if burping the system uphill doesnt solve the problem, try releasing clamps on servo hoses and prod gap with awl or tiny screwdriver to bleed out the air bubble with car idling from there.

Ginny, if yer seein the engine run slightly hotter than normal I'd start with thorough and complete DIY acid flush in Springtime purging radiator core. It's the kinda thing MB recommends twice per year - but nobody does it, not even garages who hate the process trashing their shop.