I have a Discovery 1 and works great, but lately its been overheating after 35 mins of use or if i get alot of red lights, its not the radiator because when im on the highway and i get enough ram air for it to stay cool. The clutch fan is working but the electric fans im not sure about when are they suppose to turn on, also if i put the A/C it heats up quicker. Any suggestions?

Thanks in advance!1

 

Let's cover all the bases. Not in order.

1. It might be the radiator, because on the highway you have a lot more air going through it. Check coolant jug level, and look in the space between the radiator and the condenser, and remove any build up of leaves and trash. Check radiator fins and condenser fins for gobs of mud, bugs, etc. Wash out with garden hose, but not pressure washer which will tear fins. You can take off the plastic plug on the top of the radiator and look indie with a flashlight, may see calcium build up on radiator tubes. Even if you don't see it it may be present deep inside. Throw away plastic plug and replace with $2 brass 1/2 inch NPT plug and teflon tape. If radiator is really suspect, you can have a small indy radiator shop "boil it out" with hot acid, and "rod it out" (push small rods through tubes and knock out calcium) for about $65. A blocked up radiator won't cool, and also reduces air flow to the fan clutch. Fan clutch has to see 170 degrees on the face of it to start engaging to full power.

2. Test clutch fan when cold, not running. Should not spin, should only turn a small fracion of a revolution. Crank up, fan should "roar" from air flow, mine moves enough air to spin the electric fans even though they are not on. Wait until truck warms up. Roar goes away normally. Turn off truck. Spin fan, should not free wheel, and should not turn more than 1/2 revolution or so. Bad clutch is big problem with overheating, technical section has write up on conversion with $49 Chevy unit. https://landroverforums.com/forum/di...acement-32370/ Note - cupped side of fan blades toward engine block.

3. Electric fans should come on whenever AC is turned on. If they don't, you will have poor AC cooling in traffic. They can also come on when coolant hits 212, or when coolant is even hotter and fuel temp is 70C and truck is turned off, in which case they will run for about 10 minutes. A wierd problem happens if someone reverses the wires to those fans, they blow out the grille, subtracting air from the radiator instead of adding it, making oveheat extra fast. Test fan direction by switching on truck, but don't crank, turn on AC and inside fan. Condenser fans should come on, and a wimpy plastic bag held by the grille should be pulled toward grill, not blown away.

4. In the technical section you will find a link to proper belt route. Be sure to check this out. http://api.viglink.com/api/click?for...13141551146561

5. I bought my truck and had belt route wrong, ac condenser fans wired backwards, radiator clogged up (PO had never used distilled water), wimpy thermostat, water pump started leaking, and fan clutch so bad it free wheeled. You might have a thermostat problem, but usually that does not show up just when AC is on and driving slow.

6. After I worked on all that, mine will idle and temp guage stays about 8:00 psoition. Over 9:00 is too warm. A scanner that can read live data will show you how bad things are getting.

7. The water wetter product at the auto parts store does work to drop temps while you await repairs.

 

I think is the electric fans, great help this weekend I'm goin to troubleshoot the system step by step. Thanks and great advise

 

I just went through this and was going to start a new thread. It more than likely is your radiator. Unless you've had it rodded out recently.

I changed the t-stat, hoses, water pump, flushed the system, now mind you I'm in AZ, 116 here today and I had the exact same problem. Driving with a/c on no prob, red light, needle would creep up. Finally took it over and had the rad rodded out and viola, working exactly how it should. Mine was 85% plugged inside and 45% outside, it's a wonder it was cooling at all. Have it checked out.

 

Disco 1 owners have an advantage in that the radiator is a sturdy brass and copper affair, and can be cheaply rodded out. They un-solder a side tank, and push small rods thru the tubes to knock out the calcium. Try to find an indy shop that does tractors and heavy equipment - that's their boat payment, not your little teapot. Easy to pull radiator yourself.

I had to do belt route, new belt, thermostat, rewire front fans (backwards running), new fan blade and fan clutch, then replace water pump, coolant jug cap. Tried basic radiator flush. Removed radiator. Tried white vinegar. Tried muratic acid. Still not enough. The rad shop has heated citric acid they pump thru, but the rod out made the big difference. Can idle for 1/2 hour with no issues.

But the cooling system is a series of devices, and more than one can be a problem at the same time. A data reading scanner is a big help to see exactly what the coolant temp is doing.

 

Your radiator is clogged. Replace it or rod it out.

 

Disco Mike told me exactly the same thing when I described my issues...there's no heat transference when idling, I have no tractor place around me so I had to pay the $300 but cheaper than a new rad or heaven forbid, engine.

 

Good grief. Does no one know how to search? First post on the site for the OP and it's on a topic that's been covered by 12+ threads in the past two months.

You guys are borderline too nice for me.

 

Well, I found a tractor place 35 miles away, and that was worth the diffence on the cost of the radiator. Now as to number of recent posts, sure, it is that time of year. But people waste more bandwidth yowling about which dino juice or imitation dino juice is the very best when driving sideways on the Bonneville salt flats at 87.4562 miles per hour during the full moon.

I would believe that an exchange with a lower use forum member might warrant a little more info, that's what they are asking for, and a little explanation may help. They may get to liking this place and participate more, which raises all boats.

And if the truth be known, my daddy was a car salesman, and my momma was a woman....

 

What I'm still trying to figure out is why this guy has a little dude next to his thread and it says "moderated" and his post count has not gone up.
99.99% of the time that little dude and "moderated" means spam, but he has yet to say/ask anything to warrant banning.
However, I am keeping my eye on him.
First sign of trouble and he's gone.