Temp. Guage question
Thread Starter
Senior Member
Joined: Jan 2009
Posts: 290
Likes: 22
From: Weaverville, Ca
1992 MB 190E, 2016 MB C300
Temp. Guage question
Wondering if these cars have "real" temp gages. Some Asian cars will read normal until temp reaches extreme hot. My 09 never goes above 82C after warm up no matter the driving condition. I understand that this was done to not alarm the driver on some Asian cars. Is the Benz like that?
MBWorld Fanatic!
Joined: Mar 2008
Posts: 3,714
Likes: 56
From: 1 hours drive north of Sydney Australia
2007 W204 220CDI Classic Sedan
Wondering if these cars have "real" temp gages. Some Asian cars will read normal until temp reaches extreme hot. My 09 never goes above 82C after warm up no matter the driving condition. I understand that this was done to not alarm the driver on some Asian cars. Is the Benz like that?
I have put this down to having a cooling system that is adequately engineered for the engine.
On my previous cars this was not the case .
Just one point, 82'C seems 10'C low compared with mine ( diesel) .I would check that your running temp is correct.
My guage read 92'c for years then suddenly changed to 82". I replaced the thermostat & it returned to normal. It seems that these thermostats have a habit of failing early going on some reports on this site. You might consider taking a look at the search feature.
Thread Starter
Senior Member
Joined: Jan 2009
Posts: 290
Likes: 22
From: Weaverville, Ca
1992 MB 190E, 2016 MB C300
I'm wondering if not many have noticed. I've driven my C350 in 110 degree heat with the AC on in stop and go traffic with the auxillary fan on and the temp guage doesn't vary. Got me thinking that these guages must be a fancy looking warning light.
Last edited by dennish; Jul 11, 2017 at 06:50 PM.
MBWorld Fanatic!
Joined: Mar 2008
Posts: 3,714
Likes: 56
From: 1 hours drive north of Sydney Australia
2007 W204 220CDI Classic Sedan
Hello dennish,
If your temp. guage reads 0 when cold & gradually climbs during warm up ,is mid range when the engine partially cools down then I would have to say that there is nothing wrong with it.
Have you checked what your running engine temperature should be?.
When i was determining whether it was the guage or thermostat causing my low engine coolant temp., I placed a glass thermometer in the header tank & compared readings with the guage. I found the two readings to be very similar. You could do the same.
My understanding is that if the radiator has more than sufficient capacity to cool the engine & the thermostat is doing its job efficiently then the coolant temp should not vary to any degree.
I think there has been a big improvement in engine cooling design over the years.
young John.
If your temp. guage reads 0 when cold & gradually climbs during warm up ,is mid range when the engine partially cools down then I would have to say that there is nothing wrong with it.
Have you checked what your running engine temperature should be?.
When i was determining whether it was the guage or thermostat causing my low engine coolant temp., I placed a glass thermometer in the header tank & compared readings with the guage. I found the two readings to be very similar. You could do the same.
My understanding is that if the radiator has more than sufficient capacity to cool the engine & the thermostat is doing its job efficiently then the coolant temp should not vary to any degree.
I think there has been a big improvement in engine cooling design over the years.
young John.
MBWorld Fanatic!
Joined: May 2015
Posts: 4,037
Likes: 1,012
From: Miami, FL
2003 CL 600
They are not just a glorified warning light, although they are tempered a little. If you log the actual temp sensor reported temp, it will match what the gauge displays.
The cars tend to sit on the fan turn-on point if the a/c is on and you aren't going 70+ mph. Once the fan kicks on it cools down quite well, so it turns itself back to slow speed.
On my CL, the t-stat opens around 85 and is fully open before 95, when the fan goes into higher and higher speeds. Most of the time it's sitting at 95 but I watch it on the highway and after a few minutes of cruising it will come down a bit. If it's cold out and i'm running easily it will sit at 82-85 range until the airflow goes away or I start to push it hard.
The cars tend to sit on the fan turn-on point if the a/c is on and you aren't going 70+ mph. Once the fan kicks on it cools down quite well, so it turns itself back to slow speed.
On my CL, the t-stat opens around 85 and is fully open before 95, when the fan goes into higher and higher speeds. Most of the time it's sitting at 95 but I watch it on the highway and after a few minutes of cruising it will come down a bit. If it's cold out and i'm running easily it will sit at 82-85 range until the airflow goes away or I start to push it hard.
