Which one did you instal? Any other recent cooling system work or is it still stock/original? dex or green? I recall you did your head gaskets but can't remember what you did in addition.

The OEM Diesel LR one performs differently than the Motorad.

That does seem high... I have the OEM 180 and it runs consistently at 188.6 at 55- 70 mph on the freeway. Max in town long idle is 201.

 

Dave,

I got the Amazon 180 thermostat. I did my head gaskets, as you mentioned, a few months ago. I have a newish (1 year old) radiator and water pump. I use green antifreeze (Prestone pre mixed). My Temps were without air conditioning or heat (Windows down).

I was hoping for lower Temps with the new thermostat and, indeed, they are about 10 degrees lower than before. Maybe I have an inaccurate sensor?

Best,

Charlie V

 

That's a motorad.

Those temps are ok, but about 5 degrees warmer than I would get with my motorad in similar conditions.

I would usually only top 200 when idling or going up a long hill at highway speeds.

 

I've notice mine runs a few degrees hotter with the AC powered off... not in econ mode but off.

Maybe that is your issue.

See what you get running the AC.

 

When I switched from a factory 190F thermo to the 180F Motorad, I didn't notice any change. When I replaced my radiator, average temps dropped by 5F.

 

x2 on the radiator dropping temps drastically. Seemed to flow fine, but when I compared the weight of the old rad to the new it was about 10 pounds heavier. Must of had a lot of caked up junk in it. All is well now with the new rad.

 

Hmm. I'll check it with the air con going. Heat on didn't make a difference. It should warm up a little today. Um going to do some work on it this weekend it get ready for an overdue inspection. I'll report results with and without air con. Thanks for the input.

 

Yikes I just wanted to chime in and say that the OP (though like a year old now) idea of running without a tstat on the disco is a bad idea.

Besides the simple fact that a correctly installed / maintained stock design works fine, look a little deeper at the design....

The very reason why there is a bypass spring in the tstat is BECAUSE the heater core loop can't handle high pressures or RPM/flow, ESPECIALLY an older heater core. When the tstat is closed and at IDLE it goes through the core only, but that's it - anything over idle the spring opens to release pressure.

So why do people yank all this stuff out and run a full pressure, full RPM coolant stream through the heater core.

I've hooked a hose up to that thing before and I can tell you right now, there's a decent amount of back pressure on that loop due to the fine grid design of the heater core. I WOULD NOT want a closed tstat to send everything through that (say if I had to merge or something and engine was still cold).

The design of the waterpump assy and external tstat makes it nearly impossible to safely do an inline tstat or NO tstat without a lot of modification. Even then it creates more problems and risks than it solves.



SuperSport read my mind again about the AFR and MPG, cats, CEL, etc.. just a horrible bandaid fix to run no stat lol. You'd burn enough extra gas to buy a new tstat.

FWIW when I was running hot at idle (when the sensing holes are used to detect engine temp) I took the stat out and noticed one of the holes was blocked, which is 25% of the temperature the thermostat detects. Rev the engine, it gets full flow of real temperature, opens, and temps drop instantly. THAT PART was the only really bad design flaw.

The Motorad tstat has two LARGE holes which are less likely to clog - another reason I didn't hesitate to run one.