Diesel thermostat definative answer

[Jules]

Opening the EGR early would lose you a lot of turbo power and gum up the already gummed up inlet ports, so not a good idea!

Best thing to do with the EGR is disconnect the vacuum pipe.

And any Diesel owners who wants a quick warm up time within 2 miles.......
Either retrofit an FBH kit or Buy a Petrol Car, otherwise one of these springs to mind

[HarryM1BYT]

Originally Posted by kaiser

The best advice is to reduce the use of the heater, and yes, blocking the radiator might help, but not for the blocking of the radiator itself, (which will not be in operation), but for reducing the flow of cold air around the engine and in that way limiting the cooling of the block itself.

Hope this makes a bit of sense to you!

That makes absolute sense to me and is exactly the way I see it.

I had my old stat running at 80 to 82 replaced with a new on a week or two back. The new one is running at 88 to 90 and I now have some rough mpg figures - as near as I can tell it has gained just a slight increase, maybe 2 or 3 mpg since the swap. Towing it improved from 32mpg to 34 and solo it is doing 48 to 52.

Warm up miles seems not that much different - it took around 3 miles for the stat to open and reach 88 degrees, at ambient temperatures of 12 to 16 degrees.

[HarryM1BYT]

Aside from the 75 CDTi, I run a VW CDTi as my works vehicle. That goes from home and is on the motorway at motorway speeds within a mile, yet doesn't start to warm the cabin until it has covered its first 8 to 10 miles in winter.

[wuzerk]

It is interesting that someone remarked that the only way to increase the running temperature is by doing very high speed or slogging uphill. My car was running correctly until the day I tried about 110MPH up the long hill after the Rochester M2 bridge! It has been stuck open from that day!

[Frank Incensed]

Originally Posted by wuzerk

It is interesting that someone remarked that the only way to increase the running temperature is by doing very high speed or slogging uphill.

Been there, done that. M62 - highest motorway in England - long steep gradients. Doesn't work for me. I've demonstrated, to my own satisfaction, that the only way I can get my engine hot is with the car stationary. Need to reduce the amount of air cooling radiator/engine thus increasing temperature of coolant and (eventually) engine block.

[r44712]

Out of curiosity - sorry for a bit of a hijack - where should the gauge sit when driving after 15/20 minutes including climbs? I know its only a gauge, but mine sits at a 1/4 and if I press on (when I reach a dual carrigeway), it then visibly moves up to "just under" the half way mark. Back off again and it starts to fall off again (gradually). Does that mean its shot?

[Frank Incensed]

Originally Posted by r44712

........I know its only a gauge, but mine sits at a 1/4 and if I press on (when I reach a dual carrigeway), it then visibly moves up to "just under" the half way mark.

Hi
As highlighted on other threads re temperature gauges, running temps etc, mid point on the guage can mean anything between 75C and 115C. The readings from yours would suggest that your coolant is not getting to the temperature at which your thermostat should open and that it is therefore stuck open. To confirm the actual coolant temperature in your engine use the thread about onboard diagnostics. Basically, with ignition off press in the trip meter zeroing button and keep it pressed in whilst turning the ignition switch to position 2. Scroll through the menu that appears where your mileage details normally appear, by pressing the trip meter button at 1/2 second intervals until you come to number 19. Pause for a second to give it time to lock onto menu 19, then press again at 1/2 second intervals until you get to number 7 on that menu. The number displayed there is the temperature of your coolant. You can then start the engine and the display will show the actual coolant temperature until you turn off the ignition.
Hope this helps

[James.uk]

If your car temp gauge doesn't get to the 9oclock position (normal) then it's a pretty safe bet your thermostat has stuck in the open position..

Better get it replaced before the real cold weather gets here..
...

[wuzerk]

If your thermostat is stuck open then it should help to raise the temperature if the radiator is blanked off to some extent....fine. If your thermostat is working properly then surely, blanking off the rad will be ineffective, since the stat will just open more to control the target temperature?

[Matt1960]

I have uncertainties that the thermostats stick open, but I think what in fact happens is that the wax degrades and starts the thermostat opening sooner, and sooner. I dont think this is a mechanical problem, but a wax/chemical problem.
Matt