Coolant TD5, the right one......possible change, long term service costs

[Nomad9]

Hi Forumites,

2001 TD5 Defender, recently replaced the head gasket on the Deefer, found the oil cooler connection and the water outlet connections to be quite badly corroded, replaced the outlet connection and I've now got a new cooler assembly and housing, a bargain off fleabay, not fitted yet.
The engine has done 365k and is a sweet as, pulls well, doesn't use oil and since the EGR removal seems to run better, and now uses around 11L / 100 even with the camper trailer on the back, which I've very impressed with.

When I did the head I noticed that the coolant was the red colour with coolant it was more rust. Flushed the system out with clean rain water and added the OAT Nulon coolant, seemed feasible since the system had been completely flushed. On topping the radiator sprung a leak in the middle at the bottom, replaced the radiator and topped up again, all good.......

Took a camping trip for the long weekend a week ago, came back and left the 110 in the shed, come the morning there is evidence of small ammount of red fluid underneath, check around and find the fuel cooler is leaking (front), happen to have a couple of viton o-rings lying around, fixed that up. Whats next?

I have used Nulon in a lot of my vehicles in the past and have had no problems at all. My assumption at the moment is that the water has been left to go off in the past in the Deefer, corrosion has set in and sediment has plugged up prospective gaps, now I have flushed the system out and put the right amount of coolant in the weak links are coming to the surface. Is the LR red coolant that special?

Second thing, when I bought my Deefer the previous owner fastidiously kept records and only had the Deefer serviced at a local LR agent, I've now totalled up the bills and the klms for the duration of the previous ownership, over a period twelve years and 215, 000 klms the total of $29,276 has been spent. Looking at the bills the majority is service with the occasional set of tyres and a new clutch. There has been a replacement of the starter motor and a bill to fix some oil leaks at a cost of $2230, still leaks......... a little bit, one part of the repair was caulking some fibrous material and silicon between the back of the head and the gearbox flange. Replacing the head gasket has now fixed this leak.
These totals don't include any accessories, like the bull bar and the winch.
Just wondering if this is what would be regarded as normal, it isn't often that I get the opportunity do do this sort of research. Just interested.

[PAT303]

Bloody hell,29K?????,how many motors did he replace.I would take it to a good rad shop and get the core rodded,replace all the hoses including the heater ones and get a flush and new coolant,I'd also do the paint brush test on the fan,replace it if needed.I used nulon for years in my Tdi and it's good stuff,I use Texaco extra cool gold now. Pat

[Blknight.aus]

OAT is the thinnest of all of the "coolants"

IF youve had a system thats been abused and plugged with a traditional coolant or leak stopper once the Flush is completed or OAT (and HOAT if its bad enough) the system will leak.

IMHO the OAT (AKA the red stuff) is the best coolant on the block in terms of cooling and protection. But its a bugger on maintenance and keeping it in the system.

HOAT (the blue stuff) is halfway between being not quite as good as oat at protecting almost the same in terms of cooling but easier to keep in the system.

Ethyl glycol (the green stuff) is the worst for cooling and system protection but its a doddle to use and keep in the system.

The colours are generic, some companies mix it in different colours, and the assumption is that you are at least keeping the correct mix in the system.


I ues OAT in the td5 and later v8's (or anything thats been spec'd to high performance) and ethyl glycol in everything else.

[PAT303]

For the record I've used Glycol from the word go in two LR's without and issue,my Tdi still has all it's original parts sans hoses as did my D1,OAT has the worst record in my experience in all types of motors and I do not like the stuff at all,the ''long life'' tag they give it is death on the motor,just like the fill for life in auto's. Pat

[goingbush]

I like red OAT because it weeps in advance of becoming a leak =( becoming a problem)

I prefer to have a bit of notice of an impending issue.

But green glycol is also good because you can smell it if there is a leak and shut down to sus it out.

I dont know if prev owner of my Td5 had any cooling issues, I think not going by the receipts, when I replaced all the hoses @ 170,000 klm before this trip the alloy parts under them looked as new - not like the pitted & oxided parts I would have expected to see if I was running glycol.

[Nomad9]

Hi Pat,
I was surprised as you sound when I added up the numbers, however when I troll through the bills and what was done over a period of twelve years taking into consideration the clutch kit and installation, a set of BFG's the oil leak saga was a bit exxy, a starter motor and I can also see a wiring loom upgrade for the front lights you start to get an appreciation on how much you spend.
I've just done the brakes, cylinder head, service, front steering joints, upgraded intercooler, radiator, batteries and the trailer wiring loom and I'm looking at $5k in parts alone, doing the work myself. The guy who I bought it off did everything right, he didn't skimp on repairs or servicing, he didn't take it anywhere else apart from a LR dealer. This at the time was one of the buying features for me.
Certainly mounts up..................

[Nomad9]

Hi There,
I was half expecting you to refer me to your article about vehicle prep, which I might add I have read in great detail, could well go down this track later. I agree with you, I would rather know now upfront that in the middle of know-where.
I think the previous owner has had a small leak for a while and has just been topping up with water and not additive, hence the dilution and the rusty deposits in the system. I'm hoping doing what I have now done has put things back on track. When I did the head there was evidence of water leaking down the block from the outlet and the oil cooler connection, both of which have been fixed. I think the leak has been very slight and not enough to be a real problem.
The previous owner did mention that the head had blown a plug out at some point, didn't cook the engine but the system was fixed outside the LR network because he was somewhere outside of Perth.

[Nomad9]

Hi Dave,
usual standard of response............ thank you.

[joel0407]

My TD5 Disco has been on the Rd for just over 2 months now. This is the first time I have used OAT (Nulon). I cant beleive how much this stuff leaks. After spending $50 on hose clamps, I am now replacing the top radiator hose. My only guess is the inner lining of the hose is leaking and its seeping throught the cotton braiding that runs between the layers. It leaks at all connections but only on this one hose.

[Nomad9]

Hi Joe,
Phew, thought it was something to do with what I was doing, glad to hear I'm not alone. Not that this response helps you much..........:)

[joel0407]

Hi Joe,
Phew, thought it was something to do with what I was doing, glad to hear I'm not alone. Not that this response helps you much..........:)

I started with just cleaning the fittings. The plastic fitting on the radiator was fine but the connection on the head was very slightly corroded so I cleaned it up with some steel wool.

Those spring type hose clamps leaked so I got a couple screw up hose clamps. They leaked so I got super hose clamps the bolt type. I was told that the bolt type can crush the fitting, cut the hose or both so I went gentle at first but it kept leaking so I went tighter. I'm not game to go any further so I ordered a new hose which I'll fit on Thursday (day off).

Happy Days.