Thread: What is an acceptable coolant temp for a Defender 300tdi?

Used to have VDO electric water temp and oil pressure gauges on my 300 Tdi 130 and often got high temp readings as well as low oil pressure readings, particularly when the headlights were on. Tried heaps of things regarding earths etc, nothing changed. Ended up putting on VDO mechanical ones same time as I did the pyro and boost gauges. Mechanical seems much better, thermostat is 88 deg and you can see that the gauge is in agreement. Turns out she's running much cooler and with much better oil pressure than I thought.
I also did the vent on the LH guard and the mesh gets warm so it must be doing something. My feeling is that the best place for a vent is where it can eject hot air from the turbo.

With a 15psi cap on the cooling system your water won't boil until 120C.

What is the concern with 93C?

I am running the mechanical/capillary VDO water temp gauge. And the radiator cap is new as well.

Thermostat is exactly 12 months old. and from memory is 88 Degrees.

IS there a cooler one available?

Originally Posted by 86mud

I am running the mechanical/capillary VDO water temp gauge. And the radiator cap is new as well.

Thermostat is exactly 12 months old. and from memory is 88 Degrees.

IS there a cooler one available?

Why?

A cooler thermostat doesn't set the maximum temperature. It sets the minimum temperature.

Low Temp Thermostats: What’s the Advantage? | Tuner University

Originally Posted by vnx205

Why?

A cooler thermostat doesn't set the maximum temperature. It sets the minimum temperature.

Low Temp Thermostats: What’s the Advantage? | Tuner University

yes, but they are not just open or shut, they are progressive. So a 82c cracking t/stat will flow more water at 88c as will the one that is just opening at 88c.

Dougal, I agree that cool temps may not be ideal. Not best for efficency or wear, but the LR cooling system is not a big enough heat sink to deal with load in summer. Load the truck/engine up in summer and the cooling system can not deal with it and starts pushing over 100c. Not ideal for road trips. Little spikes ok, but not sustained

My light 110 runs around at 82-88c in town and on normal HWY. But going up the Toowoomba range (empty, still light) can see the temp get to 100c.
And that not on a hot day, half way up the ambient temp is dropping noticably.

Towing my trailer out west (dead flat roads) I had to sit on 90-95km/h just to maintain 93c. If I sat on 100km/h it would go up to 100c. 800Km of 100c or more wasnt a good idea in my book.

Yes there is a Tridon 82c T/stat

I am yet to test on highway, so tonight I will be doing a 40km run up the highway to a friends house. I will report back with temp readings.

I thought there was only one thermostat available for the 300TDI - which is 88 degrees.

Thanks

Originally Posted by uninformed

yes, but they are not just open or shut, they are progressive. So a 82c cracking t/stat will flow more water at 88c as will the one that is just opening at 88c.

Dougal, I agree that cool temps may not be ideal. Not best for efficency or wear, but the LR cooling system is not a big enough heat sink to deal with load in summer. Load the truck/engine up in summer and the cooling system can not deal with it and starts pushing over 100c. Not ideal for road trips. Little spikes ok, but not sustained

My light 110 runs around at 82-88c in town and on normal HWY. But going up the Toowoomba range (empty, still light) can see the temp get to 100c.
And that not on a hot day, half way up the ambient temp is dropping noticably.

Towing my trailer out west (dead flat roads) I had to sit on 90-95km/h just to maintain 93c. If I sat on 100km/h it would go up to 100c. 800Km of 100c or more wasnt a good idea in my book.

Yes there is a Tridon 82c T/stat

Is 100C a problem?

Originally Posted by 86mud

I am yet to test on highway, so tonight I will be doing a 40km run up the highway to a friends house. I will report back with temp readings.

I thought there was only one thermostat available for the 300TDI - which is 88 degrees.

Thanks

Pretty sure I'm running the tridon 82deg, reason being my 110 wasn't heating up fast enough and stay 'too cold' for my liking. Was the Thermo not completely shutting so new one in. Honestly, as much as i don't want to admit it, i think i got mine from super cheap auto.