Our discovery has a bladder issue

[Disco33&3rd 0]

Hi all, respect to the group.

Firstly to explain the title a little more-i put a length of pipe from the overflow coolant bottle to hang just behind the front axle (less water on the chassis is good for me) so if you were to lay on the floor my disco would look we male chuckle.

So onto the query-im loosing water through the overflow & seemingly end up with the water level just on the bottom of the tank.....um explanation? 

I've recently repaired the fuel cooler with the rubber ring repair kit which went very well, I've still to write that up. I've checked all the hoses I can see & follow finding the one below the egr valve where it joins the radiator to require a wiggle to put it fully on.

I put blue food colouring in this evening hoping that may assist, I was going to use red but then I thought my subconscious mind may interpret that the disco is bleeding to death.

Can anyone help lol

[Blanco 84]

A bit more info would help the mechanics, it would help to tell us what engine we are considering here? In general though it is a symptom of excess pressure in the system, the source of which, well that depends............

[teabag 17]

I take it as a Td5 as u refer to a “fuel cooler,” your cooling system is a close circuit system so no overflow as such, but excess pressure arriving due to say a blown head gasket would be via the valve “bottle” filler cap. 

I suggest u remove your diy pipe and reinstall the correct hose. The exact cooling hose layouts can be found in LRs Rave workshop manual.

[Blanco 84]

Good point about the fuel cooler, must have been a bit early for the brain 

[Dave W 44]

Water/coolant will only flow out of the overflow when the pressure exceeds the rating of the cap. So, there are two possible causes, the coolant is under too much pressure or the cap is faulty and letting coolant out at too low a pressure.

If you have too much pressure then it's either a cooling issue and the coolant is getting too hot or something else is increasing the pressure - cylinder head leak, for example or air in the system.

I'd start by checking the cap is in good condition and work from there.

Edited February 12, 2019 by Dave W

[Blanco 84]

Perhaps a photo of your header tank would help clarify your plumbing?

[sierrafery 18]

I'd start by replacing the cap with a new genuine one to be 100% ruled out, it's impossibe to visually rule out it's pressure valve, this https://www.ebay.com/itm/Genuine-OEM-BMW-Radiator-Expansion-Water-Tank-Cap-For-3-Series-E30-E36-E46/142197526572?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649 is cheaper than genuine LR and it's perfect fit. Also it must be tightened to maximum possible

Edited February 13, 2019 by sierrafery

[Disco33&3rd 0]

Hi guys yes it's a td5 my apologies, W reg, there is no DIY pipe. The repair kit is for the fuel cooler. 4 new o rings & circlips.

Hope that adds meat to the skeleton story ☺

I appreciate your help

[Disco33&3rd 0]

Topped water up with bleed screw out, water seemed to fizz out under pressure as though additional pressure is getting in

 

[Disco33&3rd 0]

Had a good fellow do a pressure test for me.....95% certain it's the head gasket 😐