Cool running

[George Liquor]

I recently purchased a ELM 327 500K obd2 diagnostic thingy and i must say i am impressed with its abilities, for only £17 it comes with a cd to install forscan on your laptop and usb cable, just plug it in and away you go, anyway i had this plugged into my 2011 2.4 jumbo to help diagnose the temp gauge not working, i was thinking the fault was with the new cht sensor i had fitted but thanks to my new gadget i can see that the sensor is working as is the dashboard gauge. I had the engine sat idling for about a hour and no movement on the gauge but forscan was telling me the temp was in the high 40s i took it for a run and it went up to 56 degrees then cooled back down to mid 40s again, it was a cold day, the thing is the gauge starts at 60 degrees so my engine is not getting warm enough to make the needle move, i removed the thermostat a few weeks back as it was not working so i just left it out then the head was sent for skimming with the cht sensor still in place after which the temp gauge stopped moving
i thought it was the sensor so i changed it for a new one, no change, i would like to ask the panel would removing the thermostat cause this what looks like a cool running engine and also would this cool state cause any issues such as over fueling, i will be fitting a new thermostat this weekend to see what effect it has

[metalworker0]

Yes, that is what the thermostat is for, to keep the engine at running temperature which should be 75 ish or above after something like 5 miles in this weather.
No thermostat and it will be over-cooled. and so will the oil. heater will also be poor

all the best.mark

[George Liquor]

Yes, that is what the thermostat is for, to keep the engine at running temperature which should be 75 ish or above after something like 5 miles in this weather.
No thermostat and it will be over-cooled. and so will the oil. heater will also be poor

all the best.mark

Yes new thermostat tomorrow, i am surprised though i couldnt get the temp above 60 degrees although the viscous coupling that drives the fan is stiff so the fan is always spinning fast, it was like that when i bought the van, i like the noise it makes reminds me of an old bus

[metalworker0]

Viscous Fan - this is an economy device that saves fuel (when its working correctly) just done a google search that indicates that it gives fuel savings of up to 15%, with 5-10% being the average..

..also even with thermostat fitted ..the fan wafting full force air over engine will also over cool it.

Diesels do run cool ...there is difference at tick over between a petrol engine and a diesel engine ..which is the .air/ fuel ratio
petrol 14.7:1
diesel 50:1
So less fuel burnt = less heat.
If i was to start my van up in these present temperature conditions and just let it tick over ..it would never get as far as the first mark on the temperature gauge...even after an hour.
A petrol vehicle would be up to full running temperature in less than 15 mins if subjected to the same test.

Running over cooled Engine :
Will lead to more fuel consumption
Oil not reaching the right temperature ..therefor not thinning out enough to lubricate the components properly ..so causing wear.
Oil not getting hot enough to drive off moisture in the oil and in the engine.
Fuel not burning efficiently, that can also lead to "bore wash" and wear.
Along with a lot of other problems to do with the DPF and cat.
all the best.mark

[George Liquor]

Viscous Fan - this is an economy device that saves fuel (when its working correctly) just done a google search that indicates that it gives fuel savings of up to 15%, with 5-10% being the average..

..also even with thermostat fitted ..the fan wafting full force air over engine will also over cool it.

Diesels do run cool ...there is difference at tick over between a petrol engine and a diesel engine ..which is the .air/ fuel ratio
petrol 14.7:1
diesel 50:1
So less fuel burnt = less heat.
If i was to start my van up in these present temperature conditions and just let it tick over ..it would never get as far as the first mark on the temperature gauge...even after an hour.
A petrol vehicle would be up to full running temperature in less than 15 mins if subjected to the same test.

Running over cooled Engine :
Will lead to more fuel consumption
Oil not reaching the right temperature ..therefor not thinning out enough to lubricate the components properly ..so causing wear.
Oil not getting hot enough to drive off moisture in the oil and in the engine.
Fuel not burning efficiently, that can also lead to "bore wash" and wear.
Along with a lot of other problems to do with the DPF and cat.
all the best.mark

Great info thanks, i couldnt get e new thermostat today but i will tomorrow
Regards, George

[George Liquor]

Well i eventually got round to installing the new thermostat and hey presto the gauge works fine now, i was a bit sceptical to be honest as the temp sensor is dry, all good now, so anyone who's temp gauge is not working check the thermostat first might save you a headache
Regards, George