Thread: Is there a better radiator for my td5

Not worth the effort
Stock rad is good for (IIRC) around 200kw.
Can always go for a big ally one if you want but there are better uses for the money and effort.
Now if you could get thermos to work on a Td5....

Um - not quite - the pump is operating normally but circulating coolant through the block and through the heater circuit. There's a good description in RAVE in section 26.

Originally Posted by joel0407

When your engine starts and is cold, the thermostat is closed and while the pump is spinning, it's not flowing coolant/water.

It's the flow than loads up the pump not the speed it's spinning at.

Happy Days.

Bollocks ..................just can't think of anything else to say to that

Originally Posted by simonmelb

Um - not quite - the pump is operating normally but circulating coolant through the block and through the heater circuit. There's a good description in RAVE in section 26.

I don't think Joel has RAVE. I know the cooling system of a TD5 is quite unlike most others, and can be confusing , so, assuming this is about the TD5, from that excellent description in RAVE, section 26;


" The cooling system used on the diesel engine is a pressure release by-pass type system which allows coolant to circulate around the engine block and heater circuit when the thermostat is closed. With coolant not passing thru the by-pass or the radiator promotes faster heater warm-up which in turn promotes passenger comfort.


A coolant pump is mounted on a casting behind the PAS pump and is driven from the PAS pump at crankshaft speed by the auxiliary drive belt. The pump mounting casting connects with passages in the cylinder block and pumps coolant from the radiator through the cylinder block "


Now for the real doozy, the thermostat;

A plastic thermostat housing is located behind the radiator. The housing has three connections which locate the radiator bottom hose, top hose, and coolant pump feed pipe. The housing contains a wax element thermostat, and a spring loaded by-pass valve


" Thermostat Main Valve;
The thermostat is used to maintain the coolant at the optimum temp. for efficient combustion and to aid engine warm up. The thermostat is closed at temperatures below approx. 82degrees C. When the coolant temp reaches approx. 82 degrees C the thermostat starts to open and is fully open at aprox. 96 degrees C In this condition the full flow of coolant is directed thru the radiator.
The thermostat is exposed to 90% hot coolant from the engine on one side, and 10% cold coolant returning from the radiator bottom hose on the other side. Hot coolant from the engine passes from the by-pass pipe thru 4 sensing holes in the flow valve into a tube surrounding 90% of the thermostat sensitive area. Cold coolant returning from the radiator , cooled by the ambient air, conducts thru 10% of the thermostat sensitive area.

In cold ambient temps., engine temp is raised approx. 10 degrees C to compensate for heat loss of 10% exposure to the cold coolant returning from the radiator bottom hose.

By-pass flow valve

The by-pass flow valve is held closed by a light spring. It operates to further aid heater warm up. When the main valve is closed and the engine speed is below 1500 RPM the coolant pump does not produce sufficient flow & pressure to open the valve. In this condition the valve prevents coolant circulating thru the by-pass circuit and forces the coolant thru the heater matrix only. This provides a higher flow of warm coolant thru the heater matrix to improve passenger comfort in cold conditions.

When the engine speed increases above 1500RPM the coolant pump produces a greater flow and pressure than the heater circuit can take. The pressure acts on the flow valve and over comes the valve spring pressure, opening the valve and limiting the pressure in the heater circuit. The valve modulates to provide maximum coolant flow thru the heater matrix, and yet allowing excess coolant to flow into the by-pass circuit to provide the engine cooling needs at higher revs/min. "

I hope this helps, Joel. Bob

Originally Posted by Disco Muppet

Not worth the effort
Stock rad is good for (IIRC) around 200kw.
Can always go for a big ally one if you want but there are better uses for the money and effort.
Now if you could get thermos to work on a Td5....

Possibly one of the attractions of the full aluminium radiator is because the original, or OEM radiators are manufactured from aluminium with moulded plastic end tanks interconnected with tubes. In my experience, the interface between the plastic end tanks, and the aluminium centre, is where these radiators leak. The leak can be such as it only happens at the high operating temps. when driving at highway speeds, and may not produce the tell tale coolant colour on the outside of the radiator. The natural reaction to coolant loss when the engine cools down, is OMG, head gasket!. When removal of the radiator and testing will reveal the culprit [ but who wants to do that, right ? ] The plastic end radiators can not be repaired, and must be replaced. [ a.f.a.I.k.]


The life of the full aluminium radiator can be said to be much longer than the original, and can be repaired. Plus the manufacturer states the ally ones give 35% more cooling area than the original. One can only take their word on that. So there is an argument the slightly larger ally radiators are good value over their lifetime, compared to the original.


Another aftermarket TD5 radiator. Worth going to "home" to check their spiel. You will see from the single bottom spigot, it is the modified design.
Cheers, Bob

PWR Performance Products | Rover Radiators

I have to say the I am very impressed with the OEM radiator.
Mine is the original at 13 years and 170kk and I have NO coolant use.
I don't think any brass rad in an RRC would last that long.
And that is using red coolant that likes to leak from every slight hole.

My engine is stock and usually runs on 82-85c. It has been to 103 once up the alpine way towing my 1tonne camper.

It must be ready to fail! But I wll use it until it does.

Regards Philip A

Originally Posted by bob10

I don't think Joel has RAVE.

Yep, I have RAV.

Originally Posted by bob10

I know the cooling system of a TD5 is quite unlike most others, and can be confusing

Not unlike most others, Unlike anything else. I should know better to think I know what I am talking about with a LR.

I only posted yesterday in a thread about a guy who had bought or is buying his first LR. My suggestion to him which I should take on board better myself is, forget everything you previously knew about a motor vehicle becasue a LR is nothing like any other Motor Vehilce.

Eating humble pie.

Happy Days

Originally Posted by joel0407

Yep, I have RAV.




Not unlike most others, Unlike anything else. I should know better to think I know what I am talking about with a LR.

I only posted yesterday in a thread about a guy who had bought or is buying his first LR. My suggestion to him which I should take on board better myself is, forget everything you previously knew about a motor vehicle becasue a LR is nothing like any other Motor Vehilce.

Eating humble pie.

Happy Days

No worries Joel, I've had a few of those land rover moments myself. When I first set out to study the cooling system section of RAVE, I thought they were talking about the space shuttle, Bob