Thread: 78 degree thermostat

You could try a Tridon 83°C type.
This is what I use in my Disco. Works good ... mostly(ie. when the viscous hub isn't borked!)

I also got myself a 78°C version too(just in case I didn't like the operation of the 83 version), but I never used it.

Factory temp gauges are designed so they don't fluctuate quickly - prevents consumers complaining about 'non-existent' overheating. If you want to see real time temperatures consider getting an aftermarket gauge but bear in mind it is usual for the temps to fluctuate, and the range you have described seems fine for the conditions you described. Also consider getting an engine temp alarm. Saves you constantly watching the temp gauge.

If I recall correctly, installing a thermostat that opens at a lower temperature might make it worse.

Originally Posted by chrisbbarnes

Has anyone used the 78degree thermostat on their 300Tdi? My old thermostat used to make the temp gage not move from the 88 mark where ever I drove it, but since upgrading the entire cooling system and putting an new 88 degree thermostat I get 88 degree round town driving and around 92 degrees when hill driving. When towing it stays at 92 with brief temps up to 95-99 when going up long hills. I don’t tow much, only about twice a year.

Is it worth getting the 78 degree thermostat or keep with the 88 one?

*What problem are you having, as looking at your temps I don't see one.
*I recommend having a google for "what temp does a car cooling system boil" (hint: round 130 deg C )
*In addition to the above, a 300tdi if temps are starting to raise you simply need to lift your foot off the throttle more, go back a gear if needed.

Originally Posted by DazzaTD5

*What problem are you having, as looking at your temps I don't see one.
*I recommend having a google for "what temp does a car cooling system boil" (hint: round 130 deg C )
*In addition to the above, a 300tdi if temps are starting to raise you simply need to lift your foot off the throttle more, go back a gear if needed.

Thanks Daz
I’m not having a problem as such, just being cautious as a lot of people say that the 300Tdi can over heat easily. Although two people have said to me that my vehicle smells like it’s burning coolant. I have to top up my coolant by 100ml every 1000km or so, so not much loss. I don’t have any coolant leaks from any of the hoses. I don’t drive with a heavy right foot and never drive over 90km/h. Hill driving with trailer (1.5T), I’m usually in 3rd gear doing max 70km/h anyway as there is no power otherwise. Tight bends mean even using 2nd gear at lower speeds.
I was just curious if a lower thermostat temp would help with the highway driving. Just like to keep under the 100 degree mark. Off road all is good and the temp stays at 88.

thanks
Chris

Originally Posted by BreakingBad

Factory temp gauges are designed so they don't fluctuate quickly - prevents consumers complaining about 'non-existent' overheating. If you want to see real time temperatures consider getting an aftermarket gauge but bear in mind it is usual for the temps to fluctuate, and the range you have described seems fine for the conditions you described. Also consider getting an engine temp alarm. Saves you constantly watching the temp gauge.

If I recall correctly, installing a thermostat that opens at a lower temperature might make it worse.

Thanks. I have a VDO gage so I can see the temp more accurately like you said. I do have a engine temp alarm but it’s not installed yet. Some suggest setting at 102degrees, so my temps mentioned would be fine based on that setting. I just like to keep the coolant cool. I don’t want the alarm going off every 20 mins or so.

thanks
Chris