I am chasing an erratic coolant temperature issue on my Disco. The thermostat is one year old and I believe it is not the problem. I used to run 188-deg when cruising and 194-deg when idling. Recent temps are now spiking up to 210 to 215-deg when rolling at 60 to 70 mph (around 2,400 to 2,700 rpm).

I plan to replace the viscous fan and water pump which has a slight leak as preventative maintenance.

The next step is to see if the radiator is clogged using an infra red thermometer. I researched radiators and noticed Rover North offers two radiators, one @ $779 and the other @ $279. Does anyone know the difference bertween these two radiators?

RADIATOR DISCOVERY II w/SECONDARY AIR IN, RND495, PCC000710 - Rovers North - Classic Land Rover Parts

RADIATOR DISCOVERY II W/ OR W/O 2ND AIR, PLD495, PCC000710 - Rovers North - Classic Land Rover Parts

Or are there other alternatives whi would like require any modifications when installing a new radiator?

I would appreciate some guidance.

 

i would assume the first is OEM but it does not say so in the description, you can find radiators on ebay for about $175.00

 

well drowssap fells i dont know crap but maybe you will understand.

The temp of your engine is managed by the cooling system. Three parts bear the weight of controlling your temp. the radiator, the viscous fan and the water pump. with that said any thing that clogs the flow of coolant can also be a major factor.

So lets talk clogs, a broken thermostat that does not open can clog you system. Lit bits of **** i. your radiator or heater core can clog your system. to fix clogs we flush your system and if possible back flush your radiator and heater core.

Issuses with the radiator. two things on the raiator can screw up your radiators performance. clogs in the pipes the coolant flows in. the second is bent fins or clogged fins that dont allow proper air circulation.

the viscous fan clutch. what it does is contolls the amount of air that flow through you radiator, which is ultimately what contols the temp of your engine. It is a simple repair to fix this device, just rent a viscous fan tool kit at oriellys for free. it takes just a few mins to pull it.

Water pump, if they are broke you can get crap circulation of your coolant. If they go it can really suck. so there are to ways to check you water pump for future failure. the First way is to grab your fan an to shake it by pushing it toward the engine and then toward the radiator. If it has any play in it the bearing and seals are starting to fail and it is time to replace your water pump. the other sign your pump is failing is if it is leaking from the weeping hole. tHis means that the first of the two seals has failed and it needs to be replaced.

water pumps are fairly easy to replace on discoverys, the hardest part is getting off the old gasket and making sure you hace a smooth clean surface to mount the new one on.

 

your condenser fan should be turning on at just about 210 are they? check it doesn't sound like it.
the viscous fan clutch does nothing after the truck is moving, nothing.
it is the velocity of the air flow threw the radiator that provides cooling.
so if you have a problem at idle or in traffic it could be your VF, but you say your truck is 215 at 70 mph so you can rule that out as a cause, of this problem.
what thermostat did you put in a year ago, was it OEM land rover or Mondail?

 

so the two radiators listed above are for

. a Discovery with Secondary air Injection
and the other is for
.a discovery without secondary air injection

secondary air injection is a smog system that many discoverys come with. the way to tell if you have it among other ways is open the hood. look at the firewall on the passenger side if there is a device that looks like a blower attached to the firewall abou three inches below the windshield
yo have SAI

 

Both of the radiators listed on the Rovers North actually show they are made for the SAI option. Therefore, I now assume the more expensive one is the genuine radiator and the cheaper one is an OEM version.

 

I have the LR genuine gray version.

 

Thanks to all for your replies.

I am going to replace the water pump to fix the slight leak and then bleed properly to see if it will fix the temp issue.

 

i stand corrected on sai option my bad

 

Listen just did a pump on one of mine a couple of weeks ago.

Take off the fan cowl and remove the radiator hose that attaches to the T

leave the belt on and borrow the viscous fan tool a oriellys or parts store. Use the 36 mil and loosen the viscous fan, as you look at the front of the engine turn it to the left, it is reverse threads, the belt will give you the tension you need to to loosen the fan. (electrical, so remove the ground on the batt.). then a 15 mil on a breaker bar to loosen the tensioner and remove the belt. you might want to replace it

drain the coolant, remove the pulley from the pump, three 9 mil bolts. Then as you look at the engine take off the idler pulley on the passenger side, just below tensioner.

Finally, take the bolts of the pump remember which go where, clean off the gasket clean surface put on new pump.

Torque pump bolts to 18 ft lbs, torque water pump pulley bolts to 22 ft pounds