Engine: S60: - coolant temp question

benson · Jan 21st, 2011, 10:32

Hi, I bought a 2002 s60 d5 about five weeks ago now, and so far so good. However one thing which seems a little odd is the amount of time the engine takes to warm up i.e. so the needle is in the middle..

I'm used to five minutes of driving and the car is up to temp, however in my D5 in this current weather its taking more like 15 minutes. It seems very slow to get to optimum temperature compared to what I'm used to.

I thought that the thermostat might be sticking open, although having said that I dont know if this is the case as once the needle is at the middle, which it always reaches, it stays there.

MPG is alright at the moment (between 40-42mpg- calculated at pump rather than computer which tells me I'm doing 53mpg!!). This is mixed driving with 10-15mins in town and then 15miles down the motorway.

Is the above indicative of thermostat failure or would I expect the needle not reach half way if this was the problem?

Gazdok · Jan 21st, 2011, 10:40

I had a faulty thermostat last winter.
The needle would NOT go to the middle position at all.
To test the thermostat start the engine from cold with the bonnet open. Feel the hose to the radiator and check whether it warms BEFORE the thermostat opens up.

My D5 takes about 10-15 min to reach the middle position on the temperature display now.

Roger Jennings · Jan 21st, 2011, 10:43

Hi,
Until recently I had a 2006 S60 D5 and I agree with you that compared to previous cars it took about 15mins to reach a temperature whereby the needle was in the centre of the gauge. Having had it from new and pt ex it recently with 92k on it this was a continual occurence all the time. I put it down to being a diesel rather than anything else as some of the other diesels I have driven through work (Astra & Mondeo) also seemed to take a lot longer to reach operating temperatures in the middle of the gauge's scale than any petrol vehicles I have had or driven. So from my experience I doubt whether there is anything wrong with your car.
Hope this helps.
Roger

benson · Jan 21st, 2011, 11:16

ok thanks for the advice; I am comparing it to petrol cars as I havent owned a diesel for ages. And Gazdok I'll give that a go just to double check.

Jim314 · Jan 21st, 2011, 11:57

Diesels produce much less waste heat than petrol engines so they take much longer to warm up. This is a sign of the much greater efficiency of the diesel engine. More of the heat of combustion is converted to output power at the shaft and less of the heat of combustion is transferred to the engine coolant and to the exhaust gasses. Diesel exhaust gases are much cooler than those from a petrol engine. This reduces heat degradation of the turbocharger components in a diesel compared to a petrol.

One downside of this greater efficiency is that an automobile diesel will not warm up at idle; it should be driven away right after starting up to begin raising the engine temp to the proper operating range. For that reason an electric mains block heater is highly desirable in very cold climates.

And some diesels should not be slow idled for entended periods even if they were already hot. At extended slow idle these engines get cooler and cooler until they get into the range where engine wear occurs. Some diesels have a special fast idle which must be activated if extended idling is necessary.

Brendan W · Jan 21st, 2011, 16:17

I think your experience of slow warm up is normal.As Jim says they are very frugal on fuel especially noticeable at part load. My D5 has stayed below the 1/4 mark for more than 20 minutes of urban driving on some of the sub zero days this winter.Even on summer days it can take 7 miles of open road driving to approach its usual halfway mark.

S60D5-185 · Jan 21st, 2011, 16:25

Quote:

Originally Posted by benson

Hi, I bought a 2002 s60 d5 about five weeks ago now, and so far so good. However one thing which seems a little odd is the amount of time the engine takes to warm up i.e. so the needle is in the middle..

I'm used to five minutes of driving and the car is up to temp, however in my D5 in this current weather its taking more like 15 minutes. It seems very slow to get to optimum temperature compared to what I'm used to.

My 2006 S60 D5 does exactly the same and i am convinced that it is normal.

Darryl

outnumbered · Jan 21st, 2011, 18:57

Quote:

Originally Posted by Darryl

My 2006 S60 D5 does exactly the same and i am convinced that it is normal.

Darryl

my 2004 is about the same in this weather.
mike

Jan 21st, 2011, 10:32	#1
benson Junior Member Last Online: Oct 23rd, 2012 17:11 Join Date: Mar 2010 Location: hants	coolant temp question Hi, I bought a 2002 s60 d5 about five weeks ago now, and so far so good. However one thing which seems a little odd is the amount of time the engine takes to warm up i.e. so the needle is in the middle.. I'm used to five minutes of driving and the car is up to temp, however in my D5 in this current weather its taking more like 15 minutes. It seems very slow to get to optimum temperature compared to what I'm used to. I thought that the thermostat might be sticking open, although having said that I dont know if this is the case as once the needle is at the middle, which it always reaches, it stays there. MPG is alright at the moment (between 40-42mpg- calculated at pump rather than computer which tells me I'm doing 53mpg!!). This is mixed driving with 10-15mins in town and then 15miles down the motorway. Is the above indicative of thermostat failure or would I expect the needle not reach half way if this was the problem?

Jan 21st, 2011, 10:40	#2
Gazdok Master Member Last Online: Dec 31st, 2023 11:17 Join Date: Mar 2009 Location: Wigston	I had a faulty thermostat last winter. The needle would NOT go to the middle position at all. To test the thermostat start the engine from cold with the bonnet open. Feel the hose to the radiator and check whether it warms BEFORE the thermostat opens up. My D5 takes about 10-15 min to reach the middle position on the temperature display now.

Jan 21st, 2011, 10:43	#3
Roger Jennings VOC Member Last Online: Jul 22nd, 2022 17:29 Join Date: Jun 2006 Location: Yorkshire	Hi, Until recently I had a 2006 S60 D5 and I agree with you that compared to previous cars it took about 15mins to reach a temperature whereby the needle was in the centre of the gauge. Having had it from new and pt ex it recently with 92k on it this was a continual occurence all the time. I put it down to being a diesel rather than anything else as some of the other diesels I have driven through work (Astra & Mondeo) also seemed to take a lot longer to reach operating temperatures in the middle of the gauge's scale than any petrol vehicles I have had or driven. So from my experience I doubt whether there is anything wrong with your car. Hope this helps. Roger

Jan 21st, 2011, 11:16	#4
benson Junior Member Last Online: Oct 23rd, 2012 17:11 Join Date: Mar 2010 Location: hants	ok thanks for the advice; I am comparing it to petrol cars as I havent owned a diesel for ages. And Gazdok I'll give that a go just to double check.

Jan 21st, 2011, 11:57	#5
Jim314 Premier Member Last Online: Nov 20th, 2018 01:45 Join Date: Feb 2009 Location: Dallas, Texas	Diesels produce much less waste heat than petrol engines so they take much longer to warm up. This is a sign of the much greater efficiency of the diesel engine. More of the heat of combustion is converted to output power at the shaft and less of the heat of combustion is transferred to the engine coolant and to the exhaust gasses. Diesel exhaust gases are much cooler than those from a petrol engine. This reduces heat degradation of the turbocharger components in a diesel compared to a petrol. One downside of this greater efficiency is that an automobile diesel will not warm up at idle; it should be driven away right after starting up to begin raising the engine temp to the proper operating range. For that reason an electric mains block heater is highly desirable in very cold climates. And some diesels should not be slow idled for entended periods even if they were already hot. At extended slow idle these engines get cooler and cooler until they get into the range where engine wear occurs. Some diesels have a special fast idle which must be activated if extended idling is necessary.

Jan 21st, 2011, 16:17	#6
Brendan W Premier Member Last Online: Apr 2nd, 2024 19:50 Join Date: Dec 2007 Location: Wexford	I think your experience of slow warm up is normal.As Jim says they are very frugal on fuel especially noticeable at part load. My D5 has stayed below the 1/4 mark for more than 20 minutes of urban driving on some of the sub zero days this winter.Even on summer days it can take 7 miles of open road driving to approach its usual halfway mark.

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