Over Heating TD5 problem solved

[Roverlord off road spares]

Just want to share a overheating fix from a good customer of ours who bought a D2 td5 and had constant over heating problems.
The Radiator was repalced with the new spec rad, thermostat replaced, viscous fan replaced, cooling system bled and rebled numerous times, frustration set in big time fear of blown head. today i get a phone call he has solved his problem and is very happy.
The previous owner installed a new rad, bur in fitting the hoses he swapped the heater and one of the cooler hoses around the wrong was, this interrupted the coolant flow direction thus resulting on his temp rising on his nanacom, after correctly fitting the 2 hoses in the correct way all it good and it sits in the 80s on his nanacom..
I often read about over heating on td5, maybe the hoses are fitted incorrectly when replacing parts?

[Graeme]

I've read of hoses being refitted incorrectly after replacing the TD5's thermostat resulting in overheating.

[ChookD2]

I'm checking my hoses tomorrow.

[Bohica]

When I changed the thermostat I paid particular attention to what hose went where to avoid any problems.

[Roverlord off road spares]

When I changed the thermostat I paid particular attention to what hose went where to avoid any problems.

You Cant rely on that with a second hand cars as my customer found out if the previous spanner thrower didn't fit them correctly in the first place, as you presume they are correct when you took them off to fit yours.

[Bohica]

You Cant rely on that with a second hand cars as my customer found out if the previous spanner thrower didn't fit them correctly in the first place, as you presume they are correct when you took them off to fit yours.

The previous spanner thrower is an independant Land Rover Mechanic out Burwood way,

[acgmarketing]

Might be my problem too. I got the replacement thermostat from Mario and have just taken the old one out. It will be original in a 2000 td5 with 330k on it now. My symptoms were very hot to touch rocker cover, outflow pipe from engine to top passenger side of radiator very hot to touch, radiator top on passenger side very hot but by top middle of radiator it was ambient temp. Pipe from radiator to thermostat also ambient. So figured non-opening thermostat.

Just had it cooking away in a pot on the stove. Didn’t open at 70, didn’t open at 80, by 89-90 though it was happily open and letting water pass through.

I’ll still stick in the new one from Mario but now wonder what else might be causing my symptoms. Anyone have ideas from here?

[Graeme]

The radiator could be partly blocked.

[acgmarketing]

The radiator could be partly blocked.

Radiator is only about 2 years old but to check I just ran the engine in the following state:
- fan removed (was off to get to thermostat)
- no thermostat installed - so 3 open pipes where thermostat would go
- 19mm garden hose pushed into the pipe which feeds to the water pump and turn on to good pressure
- while running took bleed screw off top radiator hose to confirm water circulating back out of block to top radiator hose.

Before I ran the engine I had hose on and blocked off, by hand the pipe which runs from thermostat to join into the upper radiator hose (bypass pipe). Water ran at full hose pressure out of radiator outlet pipe (normally would feed into thermostat but open pipe. Water also ran back into expansion tank from overflow pipe and from pipe which allows water to run from the expansion tank back into pipe to water pump.

While engine running I had internal temp turned to 28 and observed water flow out of the various pipes. If I blocked any pipe by hand (avoiding getting long sleeves caught in fan belt!) it increased water flow out other openings. There was evidence of coolant being flushed out open pipes on each other pipe being blocked.

It all seems to be flowing through fine.

I did see though that the small pipe to the fuel cooler is connected to the upper of the 2 lower spigots (the one which ought to be blanked off on the new radiator and the one which connects to the oil cooler around the back of the engine is connected to the lower spigot - that’s the wrong way around so I’ll swap those over).

Other than that I’m a little stumped. Water does flow when engine is running because I can get a water jet out the thumb screw opening of the top radiator when running (I mean without the garden hose and when running before I removed the thermostat).

I guess I’ll stick in the new thermostat and see what it does. Maybe while the thermostat does open at temp perhaps the bypass openings of the old one are stuck such that the thermostat had not been getting feed heated water so as to allow it to open and start flow through the block? As in there was no bypass flow causing water to circulate through the radiator thus making thermostat open but at times it was letting some through and thus I didn’t always notice the hot engine. I’ll see what the new one in does and report more.

[ChookD2]

Well I checked all my hoses and the connections are as per the diagram in RAVE. So I may need a new thermostat as well. Mine will sit at about 90 (on Nanocom) while motoring along and when I stop at lights etc starts to climb rapidly to 98+. Then Nanocom spits the dummy with an alarm.

Not sure my fan is doing the right thing either as most people say you can hear it start up but I can't say I've ever heard it and I've heard alot of horton fans in trucks.

And through all this my SAAS temp guage (which was accurate when first installed) now reads about 10+ degrees below Nanocom. Sender is in top rad hose radiator side of bleed screw. I'm petty confident there is no air in the system.

I might start with the fan.