4.4 tdv8 will leak coolant over time, it is not a matter of if but when.

Likely coolant leaks come from:
- Oil cooler
- EGR cooler hose 'o' Ring
- Thermostat housing
- Various hoses with connectors to thermostat housing

etc SOLD | Tuned MY 2011.5 Range Rover Autobiography 4.4 TDV8 Orkney Grey | e-diff | ACC

New Toy: Unimog U1550L/37
New : G350D

Mine's top hose o-ring is now a snug-fitting 45 mm x 3.5 mm in Viton75. A slightly smaller supposedly 45x3.5 but suspected BS224 pair were first supplied which I didn't try but today found to float excessively in the housing prior to fitting a real 45x3.5 sourced from a different supplier to the bearing retailer.

ffrr14 wrote:

4.4 tdv8 will leak coolant over time, it is not a matter of if but when.

Likely coolant leaks come from:
- Oil cooler
- EGR cooler hose 'o' Ring
- Thermostat housing
- Various hoses with connectors to thermostat housing

etc

It's a possibiliy but an inspection with an endoscope will confirm. Mine's been leaking from the EGR cooler for 2+ years and I just keep topping up the coolant as the cost of replacing the EGR cooler is not worth it. If it gets worse I'll have to have it done but so far it's been just a contant small leak. 2012 TDV8 Vogue (L322)

GraemeS can you confirm the size for both the stat housing pipes is 45X3.5 , mines slightly seeping and if i'm draining it down a bit I'll do both of them , agree with a list of oring sizes would be a very useful wiki .
Ta

Both are indeed the same size.

SpitfireS wrote:

Oh I wish my (2012 4.4 TDV8) slow coolant leak would be fixed with cheap o-rings.
But it turned out to be the oil/coolant heat exchanger.

I am just tagging on here as I also have a slow coolant leak which we cannot diagnose (2012 4.4 TDV8)

I have an endoscope (1pc 2MP Endoscope Camera, IP67 Waterproof 8 MM Hard Wire Pipeline Inspection, Borescope With 8 Adjustable LED For IOS Iphone Android) from Temu £20 which is brilliant but through which I can see some red crystals in various places on the left hand block as you look at the engine, along the head gasket . However, without this endoscope I would not be able to see them . I am taking pics over time but the red crystals are not increasing, in fact they are coming off . We have changed the Oil cooler recently as well as the top rad hose LR029140 so it might have been a spill.

I do not have any solutions yet, but I wanted to lend support to the fact we all have slow coolant leaks and it is pretty much normal!

Best, Matt


. 2012 L322 4.4 TDV8 AB low mileage - a peach
1986 V8 Defender 90 County ex-Swiss Army - Red everything....

My preferred Independent: Roy Hardy. R & B AUTOS LTD, 20 Brook Road, Wimborne, Dorset, BH21 2BH 07500 866775‬ (Ex LR Chief Technician)

ffrr14 wrote:

4.4 tdv8 will leak coolant over time, it is not a matter of if but when.

Likely coolant leaks come from:
- Oil cooler
- EGR cooler hose 'o' Ring
- Thermostat housing
- Various hoses with connectors to thermostat housing

etc

I think I found one of my coolant leaks. It is the hose on the right rear side of the plenum.
I am not sure if there is an o-ring I could replace or I need to change the whole hose.
Can anyone help? what size is the o-ring? or any part number for the hose?

Click image to enlarge

Click image to enlarge