Thread: new radiator for TD5, please explain

Originally Posted by OffTrack

If you remove the restrictors the coolant flow back into the engine is likely be reduced.

It's pretty clear that drilling out the two bottom tubes will not restore operation to the old flow, and will have unpredictable results.


cheers
Paul

Here is some anecdotal evidence to consider.

I went through my records and come up with this.

Water Pump @ 71,600ks 5/04
Radiator @ 145,000ks 3/08
Headgasket @ 157,500ks 10/08

Current ks 227,000 approx.

I recall drilling out the pipes (to match original radiator) and I did not add the fuel cooler reducer.

The biggest question mark I have is the coolant temp takes time before thermostat opens up. When at 0 - 10 degrees ambient, coolant temps will take up to 15 minutes before t/stat is fully open. Another observation is my average running temp would be in the mid 80's. Further observations is when I change my coolant I feel the temps in all pipes, therefore I am getting full circulation.

Unpredictable results?

Originally Posted by feral

The biggest question mark I have is the coolant temp takes time before thermostat opens up. When at 0 - 10 degrees ambient, coolant temps will take up to 15 minutes before t/stat is fully open. Another observation is my average running temp would be in the mid 80's. Further observations is when I change my coolant I feel the temps in all pipes, therefore I am getting full circulation.

Unpredictable results?

As Bob has pointed out the original radiator was in two parts so the two inlets at the bottom were a separate cooler. This restriction was removed in the new design, so the main flow travels through the full radiator.

By removing the restrictor and opening up the blocked tube you don't restore the function of the separate cooler, instead you provide two additional outlets from the main radiator which bypass the thermostat. If you have a significant amount flow bypassing the thermostat and entering engine you are going to have longer warm up times.

I have no idea how the coolant will behave on the leg to the oil cooler. Do you? Is hot coolant being dumped into the bottom of the radiator, or are you getting coolant flowing from the radiator to the cooler? And if coolant is going direct to the oil cooler from the radiator what effect is that having?

I'd take the recommendation of LR on an engineered change which is intended to improve the reliability of the radiator over backyard mechanics who think they know better.

cheers
Paul

The coolant off the oil cooler is the coolest coolant available after the pump. The coolant then went off to the bottom 4 rows of the EU2 radiator to be cooled even further before delivering it to the fuel cooler.

The EU3 engine having the EGR cooler required that coolant for cooling the exhaust gases and no longer available for the fuel cooler.

The new radiators bottom rows are effectively cooled further being out of the main radiator flow through heat stratification.

More like an LR engineering compromise.
Regards

It would interesting to compare the oil temp/coolant temp. of a new radiator fitted untouched, and one fitted with the blanks drilled. Also , even though the Tech. Bulletin says to connect the hose from the oil cooler to the top spigot [ the completely blanked off one] ,it should be possible to get rid of the secret hose & associated pipework, & blank off both ends. Is it possible to contact LR and have them clear this up? They may have an answer to what consequences come from drilling out the blanks. Bob

Originally Posted by OffTrack

By removing the restrictor and opening up the blocked tube you don't restore the function of the separate cooler, instead you provide two additional outlets from the main radiator which bypass the thermostat. If you have a significant amount flow bypassing the thermostat and entering engine you are going to have longer warm up times.

I have no idea how the coolant will behave on the leg to the oil cooler. Do you? Is hot coolant being dumped into the bottom of the radiator, or are you getting coolant flowing from the radiator to the cooler? And if coolant is going direct to the oil cooler from the radiator what effect is that having?

I'd take the recommendation of LR on an engineered change which is intended to improve the reliability of the radiator over backyard mechanics who think they know better.

cheers
Paul

Backyard mechanics....jeez, all I was doing was adding anecdotal evidence to the discussion. I'm not arguing neither here nor there. Couldn't care less.

Edit: Forget it.

Originally Posted by northiam

The coolant off the oil cooler is the coolest coolant available after the pump. The coolant then went off to the bottom 4 rows of the EU2 radiator to be cooled even further before delivering it to the fuel cooler.

The EU3 engine having the EGR cooler required that coolant for cooling the exhaust gases and no longer available for the fuel cooler.

The new radiators bottom rows are effectively cooled further being out of the main radiator flow through heat stratification.

More like an LR engineering compromise.
Regards

I'm a little unsure of that explanation, perhaps you can help me out. Do you have a flow diagram of the EU3 engine coolant flow. It sounds like you are suggesting that in the new radiator, the bottom 4 row section is still there. However, that means effectively, there would be no coolant flow to the fuel cooler at all, considering that the flow is initiated from the oil cooler via the secret hose. That top spigot is now blanked off entirely. However, the bottom spigot, if you check out the technical bulletin, has a small orifice to facilitate flow to the fuel cooler. Where is that flow coming from? I suggest the new radiator is a full flow one, utilising the entire core, doing away with the bottom fuel cooler 4 row section. I haven't seen one , of course, and I'm open to any explanation, because coolant flow is such an important part of the TD5. Bob

Originally Posted by bob10

I'm a little unsure of that explanation, perhaps you can help me out. Do you have a flow diagram of the EU3 engine coolant flow. It sounds like you are suggesting that in the new radiator, the bottom 4 row section is still there. However, that means effectively, there would be no coolant flow to the fuel cooler at all, considering that the flow is initiated from the oil cooler via the secret hose. That top spigot is now blanked off entirely. However, the bottom spigot, if you check out the technical bulletin, has a small orifice to facilitate flow to the fuel cooler. Where is that flow coming from? I suggest the new radiator is a full flow one, utilising the entire core, doing away with the bottom fuel cooler 4 row section. I haven't seen one , of course, and I'm open to any explanation, because coolant flow is such an important part of the TD5. Bob

Its a cross flow radiator.
The EU3 radiator is one circuit, the lower part flows through to the fuel cooler.
I have seen 2003/EU3 south african delivered D2's with factory blanked off oil coolers as the EGR cooler was deleted.

Rave shows a EU3 coolant flow circuit below the EU2.

Many have fitted the newer designed radiators to EU2 D2's, some have drilled some have not. Others have fitted the fuel cooler restrictor some have not, I have not read of any issues from anywhere regardless!

I drilled the upper blank as I didnt want to leave a dead leg in the circuit.

Regards

Originally Posted by northiam

Its a cross flow radiator.
The EU3 radiator is one circuit, the lower part flows through to the fuel cooler.


I drilled the upper blank as I didnt want to leave a dead leg in the circuit.

Regards

Thanks for that, just a couple of questions. On whose advice did you drill the blank, and which way do you think the coolant flow goes, oil cooler to radiator , or vice versa? Does any one know why Land Rover said in the tech. bulletin, do not drill the blanks. How many head gasket leaks could be caused by a diversion in the coolant flow, if any? Could the change in the flow, ie opening up the blank , cause problems such as pressurising the system , and overflowing the expansion tank? Tomorrow I will go to talk to the TD5 guru at our local independent dealer, see if he has an answer. This is one subject that deserves a pedantic approach, Bob