Hi I have a 98 Discovery. I carpool to work and drive it 40 minutes about every 3 days. On my way home its usually pretty warm. My temp gauge is at a little less than half until about 30 min into my drive home i see it starting to slowly climb. Turning the heat on brings the gauge back down to normal, but if im stopped for a while it starts to climb. when i drive again it goes back to normal. ive read about other peoples heating issues but decided to post my specific problem so maybe you guys would have a good idea of whats wrong in my particular case. like i said turning heat on brings it down, and if im stopped and it starts climbing, driving brings it down. any suggestions?

By the way Ive had this car since last summer and had the same problem. I never had the problem during the fall winter or spring, or at night. Just in the summer sun really

 

Radiators clogged. I have the same year as you. That's my bet. I had the virtually exact same problem. Doing research I found that disco 1 radiators have very tight passages that clog over time. I purchased a slightly differently designed radiator from Arizona Performance Radiator and at a fraction of the cost of stock. Have had no problems since. If it's not your radiator then it's possibly your thermostat. I'd replace that just for the hell of it cause it's easy and cheap. Of course before you come to this conclusion, I would check your coolant level and do a pressure test of the cooling system to make sure your not losing fluid or if you have blown heads. But by the way your describing it, I bet it all on your radiator. Be very careful you do not overheat this thing then you will have warped heads that will lead to whole nother mess. Let us know what you find. How many miles?

 

80,000 miles. can you point me in the direction of a good replacement for the radiator. How much did it cost you with the work? Also, can i just clear the clog to give me some time before worrying about replacing the radiator. Is this something a thorough coolant flush could take care of? I was thinking about doing this, but Im not even sure where the radiator cap is on discoveries. Thanks for your help

 

Mine went out at 72,000. I went with Arizona Performance Radiator http://www.performanceradiator.com/locations.php. They were cheaper and obviousy have a different design. I do not recommend stock radiators or you'll have the same problem another 80,000. It's a very easy swap. Two bolts holding it in on top and then just the hoses. I did it myself and just about anyone can with just a dash of mechanical background. At this mileage if not done already you may want to consider new hoses and a thermostat as well. Oh, not trying to turn this into a huge dollar thing, BUT my water pump went out at 70,000. The bearings in the pump seized turning my fan into a grenade. Just may want to at least consider it. Inspect your fan clutch as well. Should rotate smoothly. Flush the system out good to and get all the croud out you can. And remember 2 gallons of coolant. Wetter Water is a good additive as well. Inspecting but replacing these components all at once all make for great peace of mind, especially with summer at hand. Again, I'd still check your coolant level and pressure test the system and the cap to verify no other problems such as bad heads etc...

 

It's worth a shot, but usually the built up sediment/metal particles bond to the radiator making a regular flush worthless. However suspended particles could be causing the clog. Another option is to take it to the radiator shop and have them power flush it (or whatever they do). I did not take this avenue as I figured the cost would be close to a new radiator. Plus I wanted to ditch the poor design of it.

 

i just had it in for an engine tune up and had the clutch fan replaced last year. also i had the lower hose replaced about a month ago. i was reading the directions in an old workshop manual for draining the coolant and they didnt recommend flushing the system after draining the coolant. is there any reason to follow this recommendation?

 

There actually is not radiator cap but a plug to bleed the system, the plug is located on the left side of the radiator (top). The fill cap is located on the expansion tank (or resivour) which is located just to the left of the radiator.

 

Has the water pump ever been replaced? You can tell if its on its way by lookin at the weep hole on the bottom of it. If there's build up its time for a new one. As far as that explanation goes, the only reason I can think of is lubrication. The coolant helps lubricate the water pump and without it (plain water) creates more friction - a potential problem with rovers. But for a flush it's only a short period of time and I see nothing wrong with that.

 

I recently flushed my system. I used the chemical, and then flushed with water 8 times when I was done. It took the whole weekend, but I was switching to Dexcool, and didn't want any regulare anitfreeze in it to contaminate. I am **** when it comes to this stuff, so I probably went way overboard, but I was having heat spikes with the AC on last 2 summers, and it is running about 10 degrees cooler now and no spikes. Some people say no Dexcool, some love it. I think it is great so far....

 

i really appreciate all your guys help. okdiscoguy can you tell me how to go about properly flushing my coolant.i have a pretty good idea of how to do it, except all the videos ive seen the car has a radiator filler cap. whats different about the discovery in that respect.