Winter warmer. Rad muff or thermostat?

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Mudstyler

Mudstyler

Active Member
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Location
Hants
My TD5 heater is taking a while to warm up (5 miles). I thought a new thermostat is all that's needs. So why do I see rad muffs advertised for defenders? Surely if the stat works ok the rad is bypassed until it reaches temperature? or am I missing something here.
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And the problem with rad muffs is plenty of cold air still gets around underneath to the rad.
I cover the lower half of my 200's rad with a section of plastic correx/card directly on the rad itself but this is to get running temperature up in cold weather.
With the old series the book used to suggest changing the stat to a higher level one for winter.
5 miles is pretty average for most vehicles to warm up though.
 
I run two thermostats a 88c summer one and a 92C winter one, also have a kenlowe hot start that brings up the temperature to 85C when plugged in and does a good job of defrosting the screen if I leave the heater lever in that position,
Also use the Kingsbury muff when the weather is artic, brings it back to the joke about the original discovery add on the TV in the eighties, showed tracks in the snow going up a mountain with a big pile with a Discovery buried in it,
But no driver as he had frozen to death on the way up because the heater was so crap,
 
You are correct about the thermostat - the water should not be circulating through the rad until it opens. However, to reduce the cooling effect around the engine before and after it opens many people fit radiator muffs. In theory, the engine should get up to temp more quickly before the stat opens. Can't say I ever saw much difference, so I don't bother. Warm clothes are a better bet :)
 
The thing is with the modern diesel engines is they are so efficient even when at full temp on the gauge if lightly loaded/worked for a few miles they can actually start to cool down again, the gauge of course shows all is good but the engine can be 10 degrees lower than the stat opening temp.
Add in the fact the defender engien is so exposed even the air passing over the block is cooling it down, so yes a rad muff certainly helps, but and theres always a but they can get critically hot in the blink in the blink of an eye.

I have owned many land rovers and all took/take 4 to 5 miles at slow to medium speed town work to get the stat to fully open, obviously if you have faster roads you will get heat faster.
 
lynall said:
The thing is with the modern diesel engines is they are so efficient even when at full temp on the gauge if lightly loaded/worked for a few miles they can actually start to cool down again, the gauge of course shows all is good but the engine can be 10 degrees lower than the stat opening temp.
Add in the fact the defender engien is so exposed even the air passing over the block is cooling it down, so yes a rad muff certainly helps, but and theres always a but they can get critically hot in the blink in the blink of an eye.

I have owned many land rovers and all took/take 4 to 5 miles at slow to medium speed town work to get the stat to fully open, obviously if you have faster roads you will get heat faster.
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THats an interesting point, why do diesels cool down a bit when lightly loaded/working? I have heard that before and I wonder what the background science is?
 
flat said:
THats an interesting point, why do diesels cool down a bit when lightly loaded/working? I have heard that before and I wonder what the background science is?
Click to expand...

Way above my pay grade!
Like I said above you wont notice it with std fit guage, but fit a capilliary unit and it is quite interesting, few winters ago outside temp as just about freezing ot maybe lower and after the long thrash up Blue bell hill so stat was fully open, I then had to drive 4 maybe 5 miles at 30mph and the temp dropped from 88 to low 70s and the heater ouptut was terrible!
The problem is made worse as people drive like pussies, so you cant load the engine so you freeze while they slide to a halt as driving to slow so no momentum.
 
The Kingsbury muff has a cut out for the inter coolers and you roll up the muff to suit the temperature you want,
 
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