Disco 2 losing coolant .. somewhere

Noticed my header tank seems to drop a little over a few weeks.
pretty sure its not going anywhere internally that it shouldn't, where else can it leak?
- Ok thats a loose question, but I mean any weak points on the header tank or associated pipework people can point me at ?
Temp runs normal, heater runs normal, just seems to drop about an inch over 3 or so weeks. And shouldn't

Take a good look at the oil cooler unit on the passenger side of the engine, towards the back end, up underneath the exhaust manifold.

through which coolant passes I assume.. ? They prone to leaking?

too some extent its normal ,and you should keep your eye on level ,remove bleed plug whilst filling to ensure it is full, a poor expansion bottle cap or a tiny hole in rad apart from numerous hose leaks can account for loss , a pressure test is best way

LR rubbish plasticy radiators are notorious; the instructions with the TD5 radiator instruct you to fill it with a distilled water/antifreeze mix.
Maybe someone should tell them that distilled water will CAUSE corrosion. What you should use is denatured water.

Speckydude said:

LR rubbish plasticy radiators are notorious; the instructions with the TD5 radiator instruct you to fill it with a distilled water/antifreeze mix.
Maybe someone should tell them that distilled water will CAUSE corrosion. What you should use is denatured water.

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My german laser supplier tells me De-ionised water is too aggresive and must be distilled water only for the Laser-this seems to conflict with your post?

I've got the same issue. For the last month or so the level was dropping quickly with no sign of where it was going. Found one of the factory clips must have weakened as when the pipe was touched water flowed out so it was changed to a jubilee clip.
It's still loosing but just slower a bit like yours.
Gas test done so head gasket fine and pressure test seems ok.
I think I might change all the hoses and clips.

Don't use ****part replacements, go with genuine coolant hoses, especially the top hose!

I will do. I already replaced the main hose at the top and it split near the hose clip before Christmas. I've cut it short for now and it seems to be holding but will look to see if a silicon set is available for the TD5

Brian S said:

I will do. I already replaced the main hose at the top and it split near the hose clip before Christmas. I've cut it short for now and it seems to be holding but will look to see if a silicon set is available for the TD5

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Roose Motorsport do a set but they are REALLY expensive.

biolandy said:

My german laser supplier tells me De-ionised water is too aggresive and must be distilled water only for the Laser-this seems to conflict with your post?

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All water that has had the ions removed will seek to replenish itself - DI water robs ions from the inside of the fluid flowing circuit (radiator, engine, laser, pump, etc.).
The use of ionically balanced clean water with corrosion protection additives (whatever the manufacturer recommends for coolant) is the best practice.

Get some UV dye in there kits on the bay come with a UV light if its an external leak you will find it in no time

Used to have the same issue. LROI Magazine even said that some D2s 'just do that'.

Wrong

Hang an empty tin under the over flow pipe on the expansion tank then top up the coolant. If the tin fills up then you've probably got too much pressure in the system, probably caused by the cap not lifting at the correct pressure. I lived with this for years in ignorant bliss until my rad sprang a leak. Having changed the rad, the top hose blew off a week later (I might have reattached it wrongly but why did it take a week to blow off). I spent a few days scaring myself that I had a blown head gasket until someone passed on the advice above. Sure enough, the tin filled up. I got an OEM cap from a dealer and the level stopped dropping immediately.

David

Brian S said:

I will do. I already replaced the main hose at the top and it split near the hose clip before Christmas. I've cut it short for now and it seems to be holding but will look to see if a silicon set is available for the TD5

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TAH said:

Noticed my header tank seems to drop a little over a few weeks.
pretty sure its not going anywhere internally that it shouldn't, where else can it leak?
- Ok thats a loose question, but I mean any weak points on the header tank or associated pipework people can point me at ?
Temp runs normal, heater runs normal, just seems to drop about an inch over 3 or so weeks. And shouldn't

Click to expand...

I had a similar issue a few weeks ago, it turned out to be a minute pinhole in the thermostat housing

Definitely top up with engine running and you may find its just coming out from the overflow pipe due to bad fitting or damaged filler cap.

lots of pointy fingers at the expansion tank cap - might replace that then as a matter of course for peace of mind - its been better of late. Cant see anything obvious otherwise. Its got OAT in it so pretty obvious to see when it comes out.. Guess I will just keep an eye - as I tend to look under there once a fortnight ish just to have a nosey around. As I said, otherwise runs mint with temp bang on . Hey ho, LR ownership..