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. [thumbsupbig]

[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,[wink11][wink11]

[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.

[acgmarketing]

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.
Sounds like could be fan if tending to go up when sitting still at lights.

Mine ran fine after the above story. Temp on nanocom got to 79/80 and pretty much sat there (78 degree thermostat put in). I didn’t give it much boot, nor much climbing or load but no signs of what I’d seen earlier. When I parked it the IR temp gun showed 80 on rocker cover, radiator and all pipes. Also 80 on inlet side of turbo and high 200/300 on turbo exhaust side.

I’ll monitor but maybe there was something astray with the old thermostat. Or did having the fuel cooler pipe attached to the upper (blocked off) spigot have something to do with it? Not sure.

[Tristanf]

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?

Hi Roverlord

Could you be a little more specific on which pipes were swapped around (or do you have a diagram of the correct connections/routing)?

[V8Ian]

Unfortunately Mario (Roverlord) cannot reply, but I'm sure one of our very knowledgeable vendors will be able to point you in the right direction.
From my experience, it's worth checking the seam on the plastic coolant reservoir. It can deteriorate to the point that it will hold enough pressure not to leak at one atmosphere, but will relieve pressure before the cap.

[Bohica]

RAVE has the cooling circuit etc. etc. You can find RAVE at Resources (http://discovery2a.com/Resources.html)

[Darkstar_Global]

I’m having the same persistent overheating issues. I just got my hands on a 2001 D2 TD5 and the previous owner did his own radiator replacement on it. I’m wondering if he swapped hoses around now because the symptoms are identical to what’s been described here. I’m gonna go poke around on the cooling system today, and I’m hoping it’s just a case of reversed hoses and perpetually trapped air because of the reversal.

[Blknight.aus]

as an also ran, some radiators have a blocked spigot on them, theres a couple of changes in the cooling system layout across the years, some after market radiators have the barbs for all variants but not all of the barbs are drilled through, If you read the sheet of paper that's supposed to come with them it tells you what ones to drill out for what year configurations.

go on, ask me how I know and why I own a right angle drill and a very specially ground set of drill bits that are mostly shank with very short twist sections with the ends of the fluke rounded....

[Darkstar_Global]

as an also ran, some radiators have a blocked spigot on them, theres a couple of changes in the cooling system layout across the years, some after market radiators have the barbs for all variants but not all of the barbs are drilled through, If you read the sheet of paper that's supposed to come with them it tells you what ones to drill out for what year configurations.

go on, ask me how I know and why I own a right angle drill and a very specially ground set of drill bits that are mostly shank with very short twist sections with the ends of the fluke rounded....

I’m going to bet you discovered this the hard way back in the day? Experience is the best instructor! I’ll definitely check that while I’m at it this morning! Thanks for the tip on that. 👍🏻

[Blknight.aus]

I’m going to bet you discovered this the hard way back in the day? Experience is the best instructor! I’ll definitely check that while I’m at it this morning! Thanks for the tip on that. 👍🏻
:BigThumb:

[Blknight.aus]

Hi Roverlord

Could you be a little more specific on which pipes were swapped around (or do you have a diagram of the correct connections/routing)?

from memory the ones that can be accidentally swapped around if you're using OEM hoses are the ones at the back of the cylinder style fuel cooler and the heater pipes along with the one that routes to the steel pipe that goes behind the block for the oil cooler (aka the secret hidden hose behind the exhaust shield that is (from memory) 1/2 inch to 3/4 inch diameters and about 40-60mm long)


there are 2 on the radiator that can be swapped over but Im not sure if that would have an effect as they port into the same section of the radiator

I think in the later system that has one of the hoses that runs to the radiator deleted its possible to miss route the hose that runs from the bottom up to the expansion tank and the one that runs to the radiator. Doable but unlikely as the hoseing doesnt want to sit that way naturally.

IF you're running one of the very cheap aftermarket kits that is a whole bunch of short hoses and a bunch of plastic fittings you have a lot more options for getting it wrong and if you have one of those kits my advice is to send it back and get a better kit but if your forced to use it...

1. mark for orientation all the hoses and what they attach to on the engine (pay attention to hose clamp positions and orientations and how to get the replacements in so they are easy to tighten)
2. remove all the hoses and lay them out in an exploded diagram kind of way around the vehicle,
3. make each hose section up and match them along side your old hoses
4. double check the security of all the clamps on the fittings
5. place on all the clamps that will secure it to engine side fittings
6. thread it all in
7. attach all the hoses and clamp them down.
8. pressure test the system
9. fill and bleed as required.

[sierrafery]

The most common mistake i've seen not once is swapping the two pipes on the Y side of the termostat then the main flow pipe goes to the bypass port and the whole cooling is mixed up

[AK83]

The most common mistake i've seen not once is swapping the two pipes on the Y side of the termostat then the main flow pipe goes to the bypass port and the whole cooling is mixed up

Guilty!!
I've done that too. But before pressurising the system and bleeding and getting it going, I did come into the study, on the PC, onto RAVE and found my fauxpax in that area. Lost a bit of fresh coolant, but at least didn't run the car and have the bro abuse me for killing his TD5.

They should have been designed with two very distinct size of hose and outlet to be sure of correct orientation.

[Darkstar_Global]

Update: After verifying all of the hoses are piped in properly, I found that there is a significant amount of air in the system. I started it up with the cap off just to observe the stream from the radiator return line, and it’s solid, until it gets an air bubble, but goes back to solid again. It’s not foamy or anything. Went to bleed the system and found that the bleeder screw is broken, so guess who has to track down a new upper coolant hose this morning? Since I’m going to have the system open today, I figure I might as well change the thermostat just in case. Once I get the system properly bled out, I think it’s gonna be all good. I’m hoping Grame Cooper has the parts in stock, because I don’t really feel like making a cross town trek out to TR Spares or Machter today. 😂