Anyone out there know what's the service life of a Disco water pump?
thermostat? I have a little over 130k on 01 Disco. I'd rather change it in my own garage on my terms rather than have it fail on the road or worse yet one of my kids or wife will drive it too long after it overheats.

Discos have the funkiest thermostat I've ever seen. They just kind dangle from the heater hose. Is that good or bad? I dont like to formulate and or proprogate an opinion about something I have no knowledge of. I dont see a lot on these forums about water pump failures like on BMWs.

PS My coolant looks pretty good, it was not Dex Cool and really clean. I flushed the radiator and it ran clean, clear water no sludge or radiator muck like you'd expect.

 

You are due for a WP IMHO. Here's pix of what happens as they age, they begin to wobble, and when that happens they are eating metal (and circulating it in the cooling system). Eventually the fan comes off and eats the radiator and the hood. By Murphy's Law, this happens while SWMBO is driving and you are off on road warrior duties eight states away.... There are some good aftermaket WP available with bronze impeller that move more water, BP Utah is one source.

Thermostat is a common bypass stat, just mounted remotely. Little metering holes in the top leg of the stat admit hot coolant to warm up the stat and make it open. Change at same time, go with OEM, or the OEM version for another Rover with the "soft spring" that operates at 10 degrees cooler; or consider the in line conventional stat mod, many write ups on that as well.

 

service life on your waterpump and t-stat was about 50k miles ago.

 

The T/Stat should be changed every 60,000 miles, the water pump, when it starts to leak or in your case, with your mileage, now.
Consider using German made water pump with the bronze impellor, made by Airtex and sold ay British parts of Utah that cares a 2 year warranty, also use a bottle of Water Wetter, Purple Ice of Super Cool from BG to give your system a little more protection.

 

Yep...If it's original to the truck then it's a pretty safe bet your water pump is living on borrowed time.

When you buy a replacement, avoid the rebuilt ones. Failure rates on them are extremely high. It's probably worth it to get a genuine, or at least a newly manufactured aftermarket part. (for example - Land Rover Water Pump (Same Fit As Genuine Part # STC4378): Water Pump Fits Most Land Rover Vehicle Models)

While doing the pump and thermostat, you should take a close look at all the hoses too. If they haven't been replaced, now would be the time to do them too...

 

Oh, and we forgot to mention - the viscous fan clutch has been holding hands with the water pump, and they usually jump off the cliff together or close to it. So a new clutch would be a good idea, especially if this one came with the truck.

 

They do make some interesting thermostats. Unlike most other thermostat setups, if you remove the thermostat, the car will not run cold, it will actually overheat. Tried it as an experiment, and it heated up faster than anything I've ever seen. The Freelander has an even weirder thermostat.

I keep a spare water pump on hand, just in case I ever need to change it, but so far I haven't needed it. I have an '01 with about 115k and it holds temperature pretty well.

There are two different engines for this year, make, and model, the TD5 and the V8. They have different thermostats, even though they look exactly the same. The TD5 works at 221 degrees and the V8 maintains 212 degrees. I have a TD5 thermostat in my car (which I put in by accident since they look exactly the same), so my truck runs at 221 degrees, but without any problem.

A lot of people say these things run really hot, but other cars I work on run at like 205 degrees or slightly cooler. The V8 is designed to run at 212 degrees, so 10 degrees hotter isn't a major difference. The problem is that they do tend to overheat.

The best thing you can do is to borrow an OBDII tester and drive the car while monitoring the temperature. If you have a V8 and you're running hotter than 220 or colder than 210 degrees, something is starting to fail, and you may as well change out the pump and the thermostat. If you're running between 212 and 220, I would say to leave it alone for now, because you're cooling system is working just fine as it is. Just remember to drive it in stop and go conditions, highway speed for a little while, and let it idle for a while. I like to let it idle for a good half hour after running the engine. If you can do all of that and not exceed 220, you're fine. If you go up to like 224 momentarily, you're still pretty okay. If you go up and stay at 224 or higher more than just momentarily (while the fan kicks in to cool it down), you may want to change stuff out.

I've driven mine in extreme conditions and got the temp up to a temporary 230. I found a small leak in the connection leading to my heater core, tightened it up and no other problems. Still haven't used the water pump I have. But I have the equipment to go check the car at will, so I do recognize that not everyone has the equipment on hand.

 

IMHO the temperature might be expected to be more in the 190s. The spec for that thermostat is starts to open at 180, fully open at 204F (from the RAVE, but then I guess I could have read the wrong page - this was on page 421 of the D2 shop manual). The spec for the electric cooling fan for overheat boost cooling is switch on the fan at 212 and switch off when back below 202F. So the idea of not running at 210 seems good to me. However, I am not an EPA enforcement specialist. I prefer to run engines where stat is not wide open, leaving a little extra capacity for long hills, towing, stuck in summer traffic, etc. There are a number of guys who have posted on here about their temperature monitoring with an Ultra Gauge, with temps in the 190s. With stock stat not the in-line mod.

With my tired old D1, I decided I did not like seeing heat spike to 227 and such, so I installed a 180F stat, temps do enter the 190s at times and cool back down promptly. I also don't trust the gauge.

Here flow chart for the cooling system.

I have a high miles '06 Kia 3.8 liter V6 (215,000 miles) , it runs at 180F like it was nailed up. Every car and truck is a little different.

 

I have a stock set up and I sit between 194 (running) and 207 (traffic). The thermostat is brand new as 2 weeks ago my temp jumped to 221 while going through a car wash and when I pulled it out I could see it was on it's last legs. I think at 230 you might want to check the water pump.

 

Is that true? I run mid 180's on my original Tstat under driving conditions, 195 solid at idle. It got up to 93 here on Monday, and at idle I still didn't cap 195.