thanks for the offer. I was away and had the shop put a 180 in while I was away. I’ll pick it up tonight and report back on temps with the 180 in and the ac fan fixed.

 

Temps from Ultra Guage
New temps with 180f non-OEM AB tstat
Temps get to a high of 216F when first starting and then stabilize to the numbers below:
Ambient temp-60F EXT temp from heating system display
Inlet air temp-75-100F from ultra gauge (The inlet to the airbox hose is falling apart and needs to be replaced)
Idle- with AC front and back on high - 206-208F
Highway 65-70mph - 199-203F
20-30mph- 201-206F

Temps are better and I do not need to run heat on the highway now to keep temps down. Should I install a OEM LR t-stat? Will it give better performance than the AB 180 tstat?
I assume based on the temps the viscous fan is working ok?

I will most likely move to an inline setup at some point in time. Will an inline with a 180F t-stat have better results than the 180F OEM?

 

Those are WAY to high in my opinion. You got bigger fish to fry. Again, in my opinion, first order of business in getting a Disco regardless of mileage, is to completely re do the cooling system unless the temps stay for the most part in darn near any condition under 200F.

On my 1200 mile fly and drive temps were just under or over 200F- safe fro the drive so I did it. I decided just as a matter of course to do a radiator and 180 t stat and fan and clutch. Driving on the road and in traffic it won’t go over 190. The only time it gets to 195, maybe 197 is if it idles for more than a few minutes- and that’s probably because I still should bleed a bit more. I have a flowkooler water pump sitting on the shelf for that inevitability as well.

I think the in line setup is a great idea and totally ingenious, but also unnecessary if you have all the other components refreshed.

I bet your radiator is done.

 

Most of the cooling system is new, radiator, water pump, hoses, tstat and rebuilt engine. Only things not changed is viscous fan, coolant tank, and heater core.

 

@wildwilly69 You have something else going on - it is possible you have a bad thermostat some of the aftermarket 180's were not even close.

The big indicator to me is going up to 216 before before the temp dropping even with a dodgy thermostat you should not get much over 212, you could try testing the temp sensor.

• I would remove it but leave it wired up
• Boil some water and get a temp with a thermostat
• Ignition on engine off
• Put the sensor in the water and compare temps should be within a deg or 2

Check the fan if that is just freewheeling it is functionally doing nothing
If you have heat the heater core is not much of an issue
Coolant tank is not part of this issue.

 

I say fan clutch then. Also, I bet you have some air bubbles in there. What kind of radiator and T stat? I did Nissins and OEM soft spring. I’ve heard of issues on aftermarket 180 T stats.

 

With the temp initially spiking to 216 I’d lean with Richard that the t-stat is sticking closed. Or possibly still some air in the system.

 

I'm not sure of the brand of the radiator (shop installed it). The 180F tstat is an AB part not OEM. I have ordered an OEM 180Tstat and new viscous fan unit. I'll also do the venting of the system again.

 

Update

I installed a new fan unit (I think this was the issue, made much louder sound when starting than the old one) and new OEM grey 180f tstat (motorad white 180F was installed before).

Temps are now:
Ambient temp-70F EXT temp from heating system display
Inlet air temp-95F from ultra gauge (new inlet box hose)
Idle- with AC front and back on high - 195F
Highway 65-70mph - 183-186F
20-30mph- under 190F

Thank you all for the input and help.

 

You're doing an awesome job tackling all those issues. Honestly, why not just switch over to the inline mod? Did mine years ago and haven't had a cooling system issue since then. About all I do is change the thermostats from summer to winter- and sometimes I don't even do that. It maintains the system integrity, but is just such an easier and simpler way to accomplish the same thing. Whatever your choice- keep up the good work and enjoying the truck!