Both my D2 and the RRS are still running the original factory thermostats, radiators and header tanks and caps with no problems but the D2 is a TD5 and the RRS is a 3.0 V6TDi, i.e. both diesels. Both are running all the original engine ancillaries on each.

 

Yeah darn auto correct on my phone... I meant "isn't

Pretty sure the D2 Diesel has a 180F thermostat (what the grey OEM 180 was originally for). Also V8 vs Diesel are two different beast altogether.

My original 03's back when they were only 2 years old were probably running way higher than either of my D2's currently. One 03 I ran to about 50K before trading it in on an 03 SE7 D2 that was preowned certified at the LR houston dealership. I sold it with 139K on it, and I never replaced head gaskets or coolant. I'm sure both of them were running well above 200F all the time.

I think as long as your D2 is well maintained, and you don't go past 210F on a regular basis you will be perfectly fine. I mean I've got a D2 with 226K on it that runs and drives like a new D2. I'm sure the head gaskets were done at least once in it's life, but I know for a fact it saw nothing but scheduled maintenance from the LR Houston Dealership. My parts 03 D2 with barely 100K on it was not taken to LR for scheduled maintenance, it has a slipped sleeve, cracked block, or bad front cover gasket, ABS faults out the wazoo, and that's why I got it for 500.00.

It all depends on how a vehicle is maintained honestly. I also personally go for used LR's with well over 100K. As first off it's had to be maintained well to make it that far, and usually most of the inop stuff has been replaced/repaired.

I think we tend to baby the coolant temps on our D2's because so many have failed or died a young death, but from what I've seen it's mainly the 4.6L 03/04 models here in TX, and we all know they roll off the factory floor without oil coolers, and that most of the owners (unless already LR owners previously) will not be taking them back to the LR dealership for the proper scheduled maintenance or repairs. I've owned 12 LR's so far with 4 of them being 03/04 D2's and I never had a single one die on me and I put well over 100K over them.

From what I've seen the 180F OEM grey thermostat, green coolant, and a properly maintained cooling system = a good running 4.0/4.6L V8.

 

1. No
2. No
3. No.
4. Yes, that too.
5. I do know and do care to have a solid all aluminium General Motors huge radiator. And real time standalone thermometer probe inside the engine outlet hose.

 

GM radiator? Like out of a silverado/tahoe/suburban? Honestly, I've never felt like the radiator was a weak spot in our cooling systems. Seems to do a fine enough job. That said, I may switch to a GM style anyway whenever the time comes to swap radiators simply because of availability.

 

All the GM vehicles I've seen (H3 Alpha 5.3L V8) use the same plastic tank/aluminum setup as our D2's. Dunno which application uses a full aluminum radiator as OEM. I agree I don't see that as a weak spot with the D2 cooling system. I see the 190F thermostat being to high of a temp for the USA (except for AK).

Also the GM based Dex-cool = crap IMHO and I'll stick to the green stuff anyday. Here in TX I'm seriously looking into some real hood louvers. I've found some 50.00 ones by Rugged Ridge (for Jeep's) that could be mounted on our D2 hood's pretty easily. They also sell a larger metal plate hood louver for TJ/JK's that "might" work on the D2's hood.

 

Engine starts closed loop at 160F, from what I have read. My goal has been to run no more than 196 and no less than 180.

 

180 t stat.

I consistently see 188 to 194. Been to 200 once that I saw sitting in traffic ac on in 100 degree heat.

 

I have the OEM 180 t-stat with a duralast hd fan clutch from auto zone. I see 188-190 driving around at most speeds in 85-90 degree weather. 193-197 dead idle for the 1-2 hours I do in my commute home. Only time I have seen 200-204 was when accelerating to keep speed going up into the mountains at 90 degrees. I've been pleased with the cooling setup but can't help but stare at it all the time because everyone has me paranoid.

 

Have the monitored loop on Scangauge for last month. Closed starts very soon after SAI pump shuts down and well below 160 F.
......

 

I figured as much, have seen several members saying closed loop starts around 175 and DiscoMike had said 160. I do not believe having the engine running as low as 175-185 would do anything detrimental to the engine. Just my opinion.