Discovery II parallel radiator

Aug 20, 2007
2,622
10
Nashville TN
Thought I'd share what the PO did to the DII I just picked up. I'm not sure on the part number for the smaller radiator, but I imagine a little digging could find you something that works. It holds 2 extra quarts of coolant over stock.

Smaller Radiator that runs parallel to the main. It has a volvo thermostat housing with a 54mm 170 degree thermostat. I drove it 900 miles home and it averaged 176* with the icarsoft plugged in. The highest temp it got was 183* leaving knoxville going 80 mph uphill for 5 miles. pretty impressive and it seems to work great. Truck has a P38 4.6 in it with 95k miles on the engine. just rolled over 92,000 miles on the truck itself.

If anyone knows if this will in anyway hurt the engine/truck/ECU or cause it to throw codes, I'm all ears. It's been this way for 15k miles with no codes though so fingers crossed.

UPDATE: I have decided toswitch to a 180* thermo stat in the new year. After a lot of research, I couldn’t find really anyone running that low a thermostat and would rather be in line with the conventional wisdom in this regard. I’m not getting any codes currently related to operating temp abs the engine runs very smooth, but I am keeping an eye on it with it being new to me. Biggest concerns being oil temp and proper combustion and not accidentally forcing the vehicle to run rich.

IMG_2299.jpgIMG_2300.jpgIMG_2301.jpgIMG_2302.jpg
 

Attachments

Last edited:

logan_gibson

Well-known member
Dec 20, 2016
219
35
Alabama
Not having the shroud is losing some cooling efficiency from the fan.

I probably would secure the hoses without zipties, or put something between the hose and metal to keep any wear from happening there.
 
Aug 20, 2007
2,622
10
Nashville TN
Not having the shroud is losing some cooling efficiency from the fan.

I probably would secure the hoses without zipties, or put something between the hose and metal to keep any wear from happening there.
the shroud is only off for the photo. will take a look at the zip ties though. (Edit: I think you're referring to the overflow hose zip tied to the radiator. will take a look at this this weekend.) I've had the truck about a week and still going through it.
 
Last edited:

Tugela

Well-known member
May 21, 2007
4,377
201
Seattle
As much as we dread overheating these engines and take great pains to prevent it, there are also risks to running them too cool. How cool is too cool? I don't know. But I believe there is a reason that the factory thermostat is 190F. The Rover V8 should run warm...just not too much. Other members here like Peter ("p m") have shared observations on this point in the past, perhaps he will chime in on this thread.
 
Aug 20, 2007
2,622
10
Nashville TN
As much as we dread overheating these engines and take great pains to prevent it, there are also risks to running them too cool. How cool is too cool? I don't know. But I believe there is a reason that the factory thermostat is 190F. The Rover V8 should run warm...just not too much. Other members here like Peter ("p m") have shared observations on this point in the past, perhaps he will chime in on this thread.
I’m definitely open to hearing from folks. New purchase so going over it and taking it to my local rover Indy in the morning to have them have a look over it as well. Easy enough to drop a 180* or 190* thermostat in if consensus is that the 170 is too low. Seller told me he researched the racing engines over in the UK and they all use 170* thermostats (his words). Of course, a racing engine gets rebuilt much more frequently and run much harder so that may also be a reason why it works for them.
 

Discomania

Active member
Feb 10, 2017
26
4
NM
A 170 thermostat won't make your car run at 170. That's simply the temperature at which the device opens. It won't run too cool. It's a bad engine and the cooling system is barely capable of keeping up under load, so this addition can't hurt anything.
 
Aug 20, 2007
2,622
10
Nashville TN
A 170 thermostat won't make your car run at 170. That's simply the temperature at which the device opens. It won't run too cool. It's a bad engine and the cooling system is barely capable of keeping up under load, so this addition can't hurt anything.
It averages 176-180 on the interstate, which peaks around 183 in ambient 65* temps. I’ll plug the scanner back in and see how it is around town. We’ll see what it does come summertime too
 

Tugela

Well-known member
May 21, 2007
4,377
201
Seattle
A 170 thermostat won't make your car run at 170. That's simply the temperature at which the device opens.
That's the issue. When the t-stat opens at a lower temperature the engine goes through a wider range of temperature swings.
 

logan_gibson

Well-known member
Dec 20, 2016
219
35
Alabama
the shroud is only off for the photo. will take a look at the zip ties though. (Edit: I think you're referring to the overflow hose zip tied to the radiator. will take a look at this this weekend.) I've had the truck about a week and still going through it.
Ah, it looked like the radiator was pushed further back, so that the shroud on the back-side of the radiator wouldn't fit. (Not talking about the top cover).
 
Aug 20, 2007
2,622
10
Nashville TN
All hoodinfo for sure. So ideally you want the
i'd be worried about more points of potential failure. especially, those plastic tee's.
i'd be worried about more points of potential failure. especially, those plastic tee's.
I've got some spares in the cubby in the back but that is a good point to keep in mind. I wonder if there are some good brass ones I could find out there.
 

jastutte

Well-known member
Nov 10, 2009
300
19
All hoodinfo for sure. So ideally you want the


I've got some spares in the cubby in the back but that is a good point to keep in mind. I wonder if there are some good brass ones I could find out there.
this guy, https://carrs4x4.com/, used to have an aluminum replacement part but i'm not seeing it on his website anymore.
 

Swedjen2

Well-known member
Sep 12, 2018
467
80
California
i'd be worried about more points of potential failure. especially, those plastic tee's.
CARRS4X4 Land Rover Discovery II 99-04 coolant Hose 4-Way Aluminum Tube
CARRS4X4 Land Rover Discovery II 99-04 coolant Hose Aluminum T w/Stainless Steel Bleeder Screw

Just searched Amazon. Bob's your uncle.
 
  • Like
Reactions: jastutte