Hello guys. I'm new to owning a discovery 1. I just got this truck the other day. 98 disco with 140,000 miles on it. Things seem ok after replacing all the fluids, spark plugs and wires. However, when I have the ac on the temp. Gage wants to start climbing up to the high end of the acceptable zone. Could I just need something as simple as a thermostat? Any insight would be appreciated.

 

The electric fans on the AC condensor are probably not working.

Let the truck cool. Re start it with the AC on and check the fans in front of the condenser.

They should always be running when the AC is on.

 

180 stat there is a part # in the tech section

Lean the rad back and be sure there is nothing in between it and the a/c condensor

Flow water from fan side forward to be sure fins are not clogged, same with a/c condensor

Be sure both electric fans work with a/c on

Be sure mechanical fan clutch is good, should have a lot of resistance when you try to spin by hand

If all else fails you may need to address the radiator, rod clean record or replace

Worst case after all that is head gaskets

Think I touched on everything?

 

I will do that and get back to you guys. Thanks for the help.

 

Quite comprehensive. The cleaning between condenser and Radiator is one of the easiest and most effective I have found. Amazing what crud lies in there.

 

Definitely try to flow water through the fins back to front to push any debris back out the way it entered instead of pushing it farther in

I have been through the ringer figuring mine out and sits around 185*to 193*? with front and rear a/c on in this 90*+++ weather

 

Had same problem replaced Radiator and temp sensor after I check the fans and found they were working and take every ones advice on the tstat's . A lot of Discovery's over heat because of those crap fans. There is a post where you can put a trick flow fan motor in and replace them. Mine have been replaced before with the trick flow.