mhuppertz

So, I have been living with a frosty cab because it's better than blocking off the radiator and loosing the benefit of the intercooler, but yesterday, bling! I had heat. The temp needle moved up to it's normal position! I have had good cab heat since then.... I guess the thermostat was never closing all the way THE WHOLE TIME I HAVE OWNED THE TRUCK! It always worked fine when it was warmer, and when I would block it off the temp would eventually come up to normal after it got a little warmer. I just assumed it was a diesel thing. I actually had to turn the heat DOWN this morning!!!

DieselSmith

hey, you can't ever complain about your truck fixing itself right? kinda wish it would do that more often!

BearKiller

It takes a while for a dead mouse to completely rot in a heater-hose.

The little heat you were experiencing was from the hot anti-freeze expanding the heater-hose just enough to allow miniscule circulation.

Now that the corpse has deteriorated more, the coolant can get to the heater-core.

Always tape the open ends of any stored hoses; it is amazing what creatures will venture into an open hose.

edwinsmith

For some reason people have this mistaken idea that engines run better if they run cooler. Nothing could be further from the truth. The hotter you run an engine the more efficient it is. You want the incoming fuel charge and air to be as cold as possible of course to maximize the charge but the rest of the engine will simply suck heat from the combustion process if the engine is to cold.

This mistaken idea leads some people to remove thermostats and other similar things to make their engines cooler and then they can't understand why their economy goes out the window.

If you had better materials and lubricants which would take the heat engines could be more efficient than they are. But it's a compromise between engine durability and efficiency.

Edwin

cumminsdriver635

My truck never would warm up in the winter either. Id have to drive at least 10 miles to even get remotely warm heat. I put a new thermostat in it, and not it is at 140 degrees in no more than 3 miles. Its awesome. I actually have heat going places in the wintertime now. Goes to 190, and cycles back down.

Eric

Jim Lane

Removing your thermostat can actually make your engine to run hotter when you need it most because the coolant is flowing through the radiator core so quickly and does not have a chance to transfer the heat through the core and fins.

This is also why sometimes you need to install an under drive pulley on the water pump to slow it down.

Also removing or having an improper # pressure cap will cause overheating because liquid under pressure raises the boiling point.

mhuppertz

Diesel engines recycle heat better than gassers which is why they are nore efficient. Running them cold defeats the purpose. If I had known my thermostat wasn't closing properly I would have replaced it immediately. I'm afraid I have caused significant cylinder bore wear running it too cold every winter. An old friend who was an aircraft engine mechanic extrordinare could tell you by feeling the ridge at the top of the block which thermostat had been run in the engine (160, 180, 210, none). The colder the engine was run the worse the wear.

MJDiesel

For the sake of fuel mileage and longevity, what is the best thermostat for one of these engines?

mhuppertz

180 deg seems to be the magic number. Lower is harmfull, higher creates maintenance issues with hoses and fluid. I would think 200 would be perfect, but they don't make sunch an animal that I know of...

Mountaineer

Yes He does.