W211 E320CDI Temperature goes high
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Joined: May 2016
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W211 E320CDI
W211 E320CDI Temperature goes high
Hey all,
i drive w211 e320cdi for over 1.5 year. I have noticed lately, that the temparature of the engine goes to around 95c and in traffic to 100c. I have changed the thermostat but it did not help (OEM one), i think it's even worse, now the normal operating temp is 95 and goes to 100 if i exceed 2200rpm or in the traffic, almost all the time.
The question would be, what can be the reason, i assume that the thermostat is not the problem since the old one was working correctly (i have checked it in hot water). My mechanic says its radiator, but i checked it and it is clean from outside (i took it out from my car).
I have no idea what's wrong, do you maybe have any clue or advice ?
i drive w211 e320cdi for over 1.5 year. I have noticed lately, that the temparature of the engine goes to around 95c and in traffic to 100c. I have changed the thermostat but it did not help (OEM one), i think it's even worse, now the normal operating temp is 95 and goes to 100 if i exceed 2200rpm or in the traffic, almost all the time.
The question would be, what can be the reason, i assume that the thermostat is not the problem since the old one was working correctly (i have checked it in hot water). My mechanic says its radiator, but i checked it and it is clean from outside (i took it out from my car).
I have no idea what's wrong, do you maybe have any clue or advice ?
Senior Member
Joined: Mar 2014
Posts: 286
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e320
have heard of them running too cool because of bad thermostat but this is the first one i remember reading about that was running hot
sorry that i have no suggestions, hopefully some experienced people will chime in
but please post back when you figure out the problem
sorry that i have no suggestions, hopefully some experienced people will chime in
but please post back when you figure out the problem
Thread Starter
Newbie
Joined: May 2016
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W211 E320CDI
It might happen that the thermostat stays closed (not opens properly) and the coolant does not go over the radiator, then you will end up with high temperature.
Here is how it looks like on my dashboard while drving
One more thing - the temeprature has never exceeded 100c, even in long time in traffic.
Here is how it looks like on my dashboard while drving
One more thing - the temeprature has never exceeded 100c, even in long time in traffic.
Last edited by kubas; May 25, 2016 at 06:12 AM.
Super Member
Joined: Jan 2010
Posts: 563
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From: The Villages, Florida
2006 E320 CDI
Since you did change the thermostat, my take would be the following:
--Low on coolant.
--Bad water pump.
--Radiator is partially clogged.
--On this one I am not too sure, but I thought I read somewhere of an electric water pump of some type. But I may have been dreaming that (LOL).
How many miles on your cdi (never mind, I see that it has 266,888km)? How did the coolant look (clean or dirty)?
Mike T.
--Low on coolant.
--Bad water pump.
--Radiator is partially clogged.
--On this one I am not too sure, but I thought I read somewhere of an electric water pump of some type. But I may have been dreaming that (LOL).
How many miles on your cdi (never mind, I see that it has 266,888km)? How did the coolant look (clean or dirty)?
Mike T.
Thread Starter
Newbie
Joined: May 2016
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W211 E320CDI
CDI has 160k miles (yes, 260k km).
- Coolant level is OK (it's clean),
- Water pump - i do not hear any strange noises, there's no leaks either,
- Is there any way to diagnose clogged radiator ? I mean it has to be from inside then ..
- There is no electric waterpump in my CDI (if existing at all ;-))
I would rather avoid replacing the radiator since it's preety expensive, first i want to exclude everything else.
- Coolant level is OK (it's clean),
- Water pump - i do not hear any strange noises, there's no leaks either,
- Is there any way to diagnose clogged radiator ? I mean it has to be from inside then ..
- There is no electric waterpump in my CDI (if existing at all ;-))
I would rather avoid replacing the radiator since it's preety expensive, first i want to exclude everything else.
Last edited by kubas; May 25, 2016 at 07:29 AM.
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Joined: Jan 2016
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From: In the Shadow of the Tetons
2013 ML350 Bluetec
Can you verify the temps you're seeing with an infrared heat sensor? You might simply have a coolant temperature sensor that isn't working like it used to. My car keeps the temperature guage pretty much pegged at the 100C line or one tick less no matter what.
In other words, I don't see a problem here. Have ambient temperatures changed? It was winter here not long ago, now it is in the 50's and 60's. I have yet to see what the car does in the 90's but I bet it won't read a cooler temperature than it does now.
In other words, I don't see a problem here. Have ambient temperatures changed? It was winter here not long ago, now it is in the 50's and 60's. I have yet to see what the car does in the 90's but I bet it won't read a cooler temperature than it does now.
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From: Venezuela, US Embassy
2003 E320, 1985 190e 2.3, 2007 E320
2003 E320 CDI overheating
I as well am experiencing overheating problems and cannot find the reason. No water leaks, brand new OEM radiator fan, scanned and no errors. Water is clean. I am going crazy with this car, never had a diesel before. I also have a 2003 E320 Elegance gasoline and have never experienced temperature problems... It passes the 100-degree mark and I immediately pull over and turn the car off until it cools. Once it cools I find that the water level has dropped yet there are no visible signs anywhere of any leaks, even under pressure vapor-wise... 
