Author Topic: Low water temperature  (Read 2241 times)

mauro12

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Low water temperature
« on: November 08, 2018, 18:40:36 »
Hello everyone, I wanted to ask you something about the water temperature of the car. Mine never reaches 80 degrees Celsius ( 180 Fahrenheit ) but always under, let’s say around 75celsius. This get worst in freeway especially in winter.
In summer the situation is opposite because I don’t mind to have the car running cooler because here in south of Italy is very warm and pagodas are well known to have overheating problems but I would like to know your opinion about this issue.
Maybe with a new thermostat it would improve the fuel economy and emissions? Thank you
Mauro Pisani
250sl 1967 5speed zf manual

MikeSimon

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Re: Low water temperature
« Reply #1 on: November 08, 2018, 18:48:59 »
Usually the sign of an open -defect - thermostat. Easy to change and inexpensive to replace.
1970/71 280SL Automatic
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Jordan

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Re: Low water temperature
« Reply #2 on: November 08, 2018, 20:27:53 »
Mauro, before you change anything get yourself an infrared temperature laser gun from an automotive store.  Very inexpensive.  Then take your car out for a good run and then use the gun to check temperatures across your engine, rad and cooling lines.  That will tell you if your temperature gauge is maybe reading a bit low and your temps are in the normal range.  No sense replacing something if it ain't broke.  It may also confirm you need to replace your thermostat.
Marcus
66 230SL  Euro 4 speed

MikeSimon

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Re: Low water temperature
« Reply #3 on: November 08, 2018, 20:40:43 »
What does your heater do? Is it blowing warm air into the passenger compartment or does it not really heat up at all? If the thermostat is bad, you will not get enough warm water through your heater core to make this work. Cheapest way to check the thermostat
1970/71 280SL Automatic
Sandy Beige
Parchment Leather
Power Steering
Automatic
Hardtop
Heated Tinted Rear Window
German specs
3rd owner

Benz Dr.

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Re: Low water temperature
« Reply #4 on: November 08, 2018, 21:09:53 »
What does your heater do? Is it blowing warm air into the passenger compartment or does it not really heat up at all? If the thermostat is bad, you will not get enough warm water through your heater core to make this work. Cheapest way to check the thermostat

I agree, as long as all of the stuff that turns the heater on is working and adjusted properly.
1966 230SL 5 speed, LSD, header pipes, 300SE distributor, ported, polished and balanced, AKA  ''The Red Rocket ''
Dan Caron's SL Barn

1970  3.5 Coupe
1961  190SL
1985   300CD  Turbo Coupe
1981  300SD
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1967 250SL
1970 280SL
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mauro12

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Re: Low water temperature
« Reply #5 on: November 09, 2018, 13:06:13 »
The heater is blowing warm air yes. Maybe these water temp indicator are not very reliable. My concern was that if the car doesn’t reach full operating temperature , this situation can lead to more rich mixture and fuel consumption. The easiest solution is the infrared gun as you said . Thank you for the advice 😉
Mauro Pisani
250sl 1967 5speed zf manual