Greetings, just wanted to share my experience with my 2004 D2 running hot. I couple months ago I purchased this D2 110k miles seemed in good shape, I immediately picked up the bluetooth ultra gauge and noticed it was running hot, 208-210 most of the time, occasionally 215 and one even once up to 221 going up a decent grade.. It would cool down to ~205 at lights or down hills, coolant and system I was told had just been flushed and checked out good by the previous owner. I ruled out some common things, viscous and aux fans seemed to check out good, oil was normal no coolant smells, no heater noises. I noticed it appeared to have an OEM/yellow thermostat housing so I picked up the grey/D2 180F thermostat from Rovers North and swapped it out this weekend and it looks like that was the issue. The old thermo seems odd though, I noticed that the 4x small sensor holes were missing on the inside top of the thermostat panel, this seems super odd but I'm pretty new to discos, has anyone seen this before?

After I installed the new one, I flushed, back flushed and bled the system and now it runs average ~183-187 highway/up small grades and ~190-194 at stop lights, seems way better.. Anyway just wanted to share, maybe it will help some one else. I'm also going to pull the old thermo out of the housing and test it to see if maybe it was also sticking, the holes missing seem like a red flag though?





-mike

 

Sounds like a stock temp 190/195F thermostat to me. D2's were designed to run hotter (thanks BMW) to help with emissions. 210-225F was the normal temp range back then way before anyone knew about the 180F unit which was first installed on the TD5 vs 4.0/4.6L V8's

 

Here is my cheat sheet info I have saved about our D2 thermostats:
Thor V8 Thermostat; check for Celsius rating stamped on housing ***DON'T BUY A STANT!***

• #PEM100990 - Cream is 190F/88C° with Hard Spring (Designed for TD5 and V8 applications)
• #PEM100990B / PEM101020 - Black or Cream is 180F/82C° with Hard Spring (Designed for a V8 and used as a stopgap with Freelander engines)
• #PEL500110 - Gray is 180F/82C° with Light/Soft Spring (Freelander engines)
• #AJ813558 - metal thermostat housing Jaguar 3.0L V6