My Disco II Build

BMWJNKY

Member
I did an inline t-stat to my D2 and even on 100+ deg days on the freeway my temps are high 180's while moving and right around 200 if I come off the freeway and get stuck at a long light. Before I did the inline mod in a snow storm with outside temps in the upper 20's my engine was getting up to 195 deg. The engine temps was the main reason I did the mod but the other advantage is it deletes a couple hoses from the system and now if I need a new t-stat or want to keep the engine temp higher in the winter all I need is a t-stat from a basic Chevy small block 350. For the last 7-8 days the lowest daytime temp we have had other than today was about 106 and my engine temps are holding steady in the mid 180's with my city street commute.
 

MStudt

Adventurer
We're putting the Rover aside for a while, and will be revisiting the Rover when we come back through the area next year. We're not giving up on this yet, but we need to move on for now. We realized this trip wasn't about the vehicle it was about the trip. We're going to work fast on our 4runner that's taken us around the country already, and should be on the road in a 2-3 weeks.
 

99Discovery

Adventurer
I haven't read every post in your build thread, just stumbled on your cooling issues. I can tell you this from multiple vehicles, when something in the cooling system fails, REPLACE IT ALL. You will be ahead time, money AND reliability if you do so. Sounds like you have replaced some parts. So, here is a list. Whatever on this list, REPLACE. If it has already been replaced within the past year and 15k miles (except the radiator, it can go 3 years and 30k miles) then you can keep it:

-ALL rubber hoses (fire wall heater core hoses optional, if they are in good shape, keep up. Primarily, upper and lower radiator hoses and all block/pump hoses.)
-Fan clutch
-Water Pump
-Thermostat. USE A GENUINE TD5 LAND ROVER THERMOSTAT. If you are having temp control problems start here. Some have had mixed results with Motorad/3rd party T-Stats. You are beyond experimenting now, get the Land Rover Part.
-Radiator
-Radiator Cap
-Expansion Tank
-Water Pump
-Idler and tension pullys (while you are in there)
-Serpentine belt
-Coolant temperature (optional)
-Throttle body spacer kit/gasket (optional)

Cooling system overhaul can be done once every 100k miles or so, during a lazy saturday. It costs a bit, but I've been much happier with my vehicles that I've bought the bullet on this service.

Like others, my D2 is typically at 188F on the highway, 190-194 on the trail (or in the winter, I dunno why it runs hotter in the winter but it does, must be the electric AC fan), and I've seen above 200 in 4-low in triple digit heat of the Utah summers, but once I get away from crawling it drops back down. If you are 215+, especially in the 220s, you are going to blow a head gasket and like many your disco dream will either die or become extremely expensive.
 

MStudt

Adventurer
I haven't read every post in your build thread, just stumbled on your cooling issues. I can tell you this from multiple vehicles, when something in the cooling system fails, REPLACE IT ALL. You will be ahead time, money AND reliability if you do so. Sounds like you have replaced some parts. So, here is a list. Whatever on this list, REPLACE. If it has already been replaced within the past year and 15k miles (except the radiator, it can go 3 years and 30k miles) then you can keep it:

-ALL rubber hoses (fire wall heater core hoses optional, if they are in good shape, keep up. Primarily, upper and lower radiator hoses and all block/pump hoses.)
-Fan clutch
-Water Pump
-Thermostat. USE A GENUINE TD5 LAND ROVER THERMOSTAT. If you are having temp control problems start here. Some have had mixed results with Motorad/3rd party T-Stats. You are beyond experimenting now, get the Land Rover Part.
-Radiator
-Radiator Cap
-Expansion Tank
-Water Pump
-Idler and tension pullys (while you are in there)
-Serpentine belt
-Coolant temperature (optional)
-Throttle body spacer kit/gasket (optional)

Cooling system overhaul can be done once every 100k miles or so, during a lazy saturday. It costs a bit, but I've been much happier with my vehicles that I've bought the bullet on this service.

Like others, my D2 is typically at 188F on the highway, 190-194 on the trail (or in the winter, I dunno why it runs hotter in the winter but it does, must be the electric AC fan), and I've seen above 200 in 4-low in triple digit heat of the Utah summers, but once I get away from crawling it drops back down. If you are 215+, especially in the 220s, you are going to blow a head gasket and like many your disco dream will either die or become extremely expensive.

Everything is brand new. Brand new expansion tank, hoses, radiator, sensors, t-stat, water pump, viscus fan, belt, pulleys, LR burped system, and Water Wetter. We don't have a blown head gasket or any leaks. We have a secondary temp gauge so we're not relying on the untrusty LR dash gauge. The engine is brand new from Turner Engineering, and the engine runs smooth as can be.
 

99Discovery

Adventurer
Then I'd be willing to bet your thermostat is bad. Probably bad from the get go. If you are running a 180F thermostat and are seeing 215-220F temps something is wrong. Ultra guage of 220F is insanely bad. I'd swap out the temperature sender while I was at it to make sure it's reading right (I believe it is, based on your thermometer results).

If you aren't running a 180F thermostat, that's probably your first problem. It's cheap and easy to swap. Don't trust 190F stock thermostats if you want your Turner BLock to last. The stock thermostat is part of the reason the D2 is listed as one of the most unreliable vehicles ever sold.

You should be 188-194F standard 200-204 wheeling in the desert.
 
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MStudt

Adventurer
Then I'd be willing to bet your thermostat is bad. Probably bad from the get go. If you are running a 180F thermostat and are seeing 215-220F temps something is wrong. Ultra guage of 220F is insanely bad. I'd swap out the temperature sender while I was at it to make sure it's reading right (I believe it is, based on your thermometer results).

If you aren't running a 180F thermostat, that's probably your first problem. It's cheap and easy to swap. Don't trust 190F stock thermostats if you want your Turner BLock to last. The stock thermostat is part of the reason the D2 is listed as one of the most unreliable vehicles ever sold.

You should be 188-194F standard 200-204 wheeling in the desert.

We installed a 180* t-stat with the new engine (OEM), and that could have been faulty. After taking it into a shop they swapped the t-stat with another 180* (non OEM), and we have the same results. I think when we start working on it again I'll be installing a Chevy t-stat to simplify everything.
 

jfe

New member
After owning 2 D3's I'm itching for a D2 that I can modify the crap out of with nice 33" wheels etc to rock crawl when necessary. Par your engine wows this thread exclamated the D2 as "go to" vehicle seeing my love relation with the brand, be it TD5 or V8.
Stuck in there, in the end I truly believe it will be a simple fix after all you've already spend and done to the motor.


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David Harris

Expedition Leader
I'm running the 180* stat, but I'm not certain is working properly. Both fans have been replaced, and are both working now. I'll have a better idea today on the temps since my wife is driving the Rover around today.

Let me know about your inline setup. I was looking into that a couple months ago, but never got around to doing anything about it.

Forget about replacing anything else in the cooling system until you get a new radiator. They are cheap and are disposable parts every few years.

David
 

lwg

Member
Now mine was at 212-217 during my drive home from CO to UT in the winter time before I learned those numbers are way high. After I replaced the above, the temps have been great. Without full on armchair diagnosing, my money is on the fan(s) not working well, the radiator is clogged (half of mine was cold, half was hot), or the absolute nightmare of a clogged coolant passage in the head(s) or block.

Just an FYI, 212-217 IS NOT certain death! I have a cooling system that is working perfectly and see temps go from 193 (coasting downhill) to 220 while sitting in city traffic with AC on and 100* ambient temps outside. I'm running the 180* thermostat and have a new HD fan clutch. I live at 4500 ft in the dry desert so take that into consideration.

To the OP, you definitely have an issue. My Gus's is an air pocket or something.



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kcabpilot

Observer
One of the last tools I bought was a vacuum bleeder. It sucks all of the air out of the system after which you can check for leaks by seeing if it holds. Then you stick the inlet hose into your jug of new coolant, open the valve and it sucks it in with no air. Very easy to use with no mess. It has a universal rubber cone fitting so will work on virtually any car.
 

MStudt

Adventurer
The Rover is now sitting for more than likely the next year. We know this can be fixed, and we also know we'll fix it next summer when we head back home. For now we're embarking on a 4 week adventure from St. Louis to Eugen Oregon where we'll be taking up residence.
 
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Longtallsally

Adventurer
Just an FYI, 212-217 IS NOT certain death! I have a cooling system that is working perfectly and see temps go from 193 (coasting downhill) to 220 while sitting in city traffic with AC on and 100* ambient temps outside. I'm running the 180* thermostat and have a new HD fan clutch. I live at 4500 ft in the dry desert so take that into consideration.

Absolutely correct. However, I have to think it's not going to win any longevity awards, and I also drove mine back from Estes Park to UT in a snow storm, so it was friggin cold. According to the conversations I've had with Great Basin Rovers, those numbers are acceptable as well and were dialed in to help with emissions from the factory. I'm just a nut about stuff and always like to have head room just in case. We too live at over 4k feet and have a psycho summer in the last 2 months basically being at or around 100F every day (I friggin HATE it!) and it most certainly has tested the poor old Disco. If I idle for more than 3 minutes with one or both AC units on, it will still climb to 208F on crazy hot days, but moving at 30mph and up it will stay pretty solid at 190-195F, which I'm OK with. It even blew the fuse for the condenser fan the other day I have to believe due to having to run so hard at stop and go speeds. Ironically, it didn't impact the temps to the coolant.

Anyway, the point is, the Disco really is a horrible piece of junk in general. I really enjoy driving mine and like looking at them all set up A LOT. It also has never left me stranded and critical systems like the engine running, and the AC and heat have worked pretty well. But it's always a crap shoot as to what might go wrong every time I get in it. As it lives a ridiculously easy life as basically a minivan and truck for us as a 3rd regular driver, I don't expect much of than what I've asked of it, but I'd probably never take it on an "expedition" as I just don't trust it that much.
 

MStudt

Adventurer
Well it has been a year...any updates?

I have a small update.

The Rover is now in Oregon, and parked in my garage to begin working on it. After all the messing around over the last year we came to the conclusion that the t-stats have been bad. I'm in the process of gathering parts for an inline t-stat mod that should hopefully cure the high temps. Hopefully within the next month I'll have things pulled apart, flushed, and put back together.
 

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