Thread: D2 overheating TOTALLY FINALLY solved v8 and Tdi

Originally Posted by Pedro_The_Swift

Hey Dave,, would a cold air intake (from the front) make any sense, improve anything?

it would make some improvements to the engine perfomrance and might lower the temps marginally for the same sorts of reason lowering the charge air temp of a turbo diesel does but I wouldnt expect too much.

venting the hot air out of the engine bay would be my first option and while bonnet vents are being discussed I would personally be looking at side vents down near the front doors leading edges to get the air past the whole engine.

the layout of the cooling system does lend itself to using the AC electric fans on a timer to drop the coolant temp of the radiator and then allowing convection cycling to cool the whole engine bay. I've experimented with this on a D1tdi200 by using a 50 degree switch on top of the thermostat housing on the AC fans first to drive a light with out the cooling fans and then with the cooling fans. without the fans it took about 40 minutes for the light to go out and with about 15.

Never did it for a D2 but it might be worth an expeiment.

Think the D2 is complex?
Look at this puppy! LOL
Thermostat Land Rover Discovery 3 & Range Rover Sport 2.7L Diesel Euro 4 LR009562

To Geoff86RRC,
Sorry to hear about your troubles. I think you still have another issue.

I know you said you had a new radiator, but internal design is important. Can you check water temp leaving the bottom hose and compare this to the inlet.
You should have a minimum difference of 25 degrees at all times - 30 with the AC off. These are my values on a P38 in a hot humid SE queensland summer. These figures never change unless I idle downwind with AC on high for more than 10 minutes and then the radiator outlet moves to 77 and inlet temp rises to 98. Of course they are different in the winter - but only 5 degrees at most.

97 is not too hot - I have a friend with a very expensive late model 2 litre turbo BMW and it runs at 105-110 in hot idling traffic after a hard run - via OBD.

As an aside, fuel economy improves with elevated operating temperatures - according to the research articles I have read.

To give everyone some perspective on what is too hot, here are some other figures which may help your viewpoint.

50/50 coolant under pressure has a boiling point around 130 celcius.

Water temperature leaving the oil cooler of a TD5( all new components) is 107-110 when idling after a normal shopping type run. I know that because I measure it on my TD5. That is why I use very high quality oil and change out at 8000km

Air cooled Piston engine aircraft run oil temperatures in the 100 - 110 during the climb and when taxiing on a hot day with a redline max of 120. A 4 cylinder only holds 4-6 litres, so a small quantity has to absorb a lot of heat.
Blocks do crack if they are cooled too rapidly in descent - plenty of evidence in the aviation community.

So a D2 at 95 is not really a big problem provided you have your cooling system in top order and keep on top of it.

TD5 radiator BTW operates at very similar values to a P38.However it is very much affected by high inlet temperatures. It has to reject far more heat than the D2 V8 because it is on boost 90% of the time and the intercooler just stays hot.
As a rule of thumb every 5 degrees inlet air temp should add about 1 degree to the water temp - according to a cooling system design document I read some time ago.

Souping up your TD5 or TDi with higher EGT ,s is also a very quick way to overwhelm the design point of the factory cooling system.

I personally dont like higher temps, but I believe its a design point and I stick with it. I just look after my cooling systems. However I dont discount any of the mods or info by the other posters above.
I would like to try the mod myself and gather some hard data across the cooling system when I have time. I have so many other projects.

The figures for my P38 are very accurate figures measured by the 2 sensor engine guard from North Queensland - best and most accurate out there from my testing. I have verified its accuracy.


If you dont have these differential values mentioned above then there could be an issue with your new radiator internal flow design - maybe?
Lastly you need to pull the plugs on all the cylinders to check if any piston top is steamed clean. If so you you have bigger issues.

Peter Geoff do3snt have a problem. He has a vehicle that was doing what LR designed it to do....run far too hot for an old alloy pushrod engine for emissions and economy. Power and longevity are both improved with lower temps. Forget BMW examples....this is not a tight tolerance high tech multi valve. There are are lot of long time owners here that know the Thor problems well. Same in the US. Most people here run an 82 degree thermostat as a 3 way and a few are moving to the 82 inline (top hose) in efforts to reduce running temps.

Cheers

Just from my latest experience, with a new 4.6, new water pump, new radiator, new expansion box etc, the cream colour thermostat which says 82 degree inside it ( non gen. I think) was running between 92-96 degree on the nanocom,

so I changed it to a genuine Land Rover Freelander gray #500110 thermostat and now running at 86-90 degree,

I push the thermostat spring down on the old cream one with a screwdriver and the bloody thing fell apart inside

not the the first person to do this but just goes to show

Originally Posted by ozscott

Peter Geoff do3snt have a problem. He has a vehicle that was doing what LR designed it to do....run far too hot for an old alloy pushrod engine for emissions and economy. Power and longevity are both improved with lower temps. Forget BMW examples....this is not a tight tolerance high tech multi valve. There are are lot of long time owners here that know the Thor problems well. Same in the US. Most people here run an 82 degree thermostat as a 3 way and a few are moving to the 82 inline (top hose) in efforts to reduce running temps.

Cheers

I really welcome the discussion and after all no two vehicles are the same and neither are any two sets of operating conditions. Most of us have have/had many many land Rovers of various types and descriptions and all I can say is that I know that there is something wrong with the three way 87 or 93 degree thermostat on the THOR v8. I have had three RRCs in PNG both Papua and Highlands. I had a 74 in 90 still going strong. I had a 67swb 2.25 which out performed new nissans in the bush. Slower, noisier, hotter, and bumpier but got there and back. RRCs were the only things that stood up in the harsh conditions over the longer term. On a number of occasions I literally went to the end of the road. Literally. My series and my range rovers brought me back and I never ever ever had any cooling probs. This D2/P38 is just wrong. Sorry. No judgment. I agree with inline Scott. I also agree with threeway Pedro. I just put the in line 82 in before going to a threeway 82. I believe you Pedro, I was just sick of it. In fact I asked Murray to get me a soft spring 82 from a Freelander but he put on the inline. I could probably have done either but this is what I did. When I have some time I'm going to try and an 82 three-way perhaps even the new three-way which is able to be opened and is discussed on the other link that was started by Pedro all those years ago called American knowhow. Have a look at it as well. I have just been out on a very very hot day hard-driving north of Brisbane and my temps were sitting way down around 82 on the move and coming up to 86 when I stopped. I don't care about extra fuel burn. Emissions are nonsense and a joke. 98 percent of lifetime emissions occur before it is sold. I am going to look at an electric pump on a timer for circulation on cool down. I am also looking at an electric shutoff for quicker warm up.
Off topic I have some Bridgestone A/T 245 16 70s and am enjoying them. Had Nexxon roadan before...
Cheers

In this weather the inline sits at 82 when moving and idles at 86 or 88
still happy John

Cooler weather cooler running. As I get around BNE with this rain with the in line thermostat I am sitting on 82 in the day and 77 At night. Might be a bit cool so I am going to change to an 87. And the v8 loves the humidity. A softer easier smoother running engine. Lovely!