Discovery coolant question

Hi all, I have a 2002 Disco 2 v8.
I have noticed when driving that the water sound comes from behind the dashboard on acceleration, also my coolant level drops gradually over so many hundreds of miles. Is this linked? Had a search and people mention the heater matrix and that air could be in the system.

Car hasn't got a head gasket issue as this has been checked and I've seen. I visible signs of leaks so bit unsure where the coolant is going!

Thanks

R222RWD said:

Hi all, I have a 2002 Disco 2 v8.
I have noticed when driving that the water sound comes from behind the dashboard on acceleration, also my coolant level drops gradually over so many hundreds of miles. Is this linked? Had a search and people mention the heater matrix and that air could be in the system.

Car hasn't got a head gasket issue as this has been checked and I've seen. I visible signs of leaks so bit unsure where the coolant is going!

Thanks

Click to expand...

I'm no stranger to coolant leaks on my td5, having had head gasket failure amongst other things. When my water pump was on its way out, i got the noises you describe, it is as you say, bubbles in the heater matrix due to low coolant. You obviously have a leak somewhere, check all hoses, the rad and the water pump for leaks. You could have a pinhole in one of the hoses for example.

Bobdog said:

I'm no stranger to coolant leaks on my td5, having had head gasket failure amongst other things. When my water pump was on its way out, i got the noises you describe, it is as you say, bubbles in the heater matrix due to low coolant. You obviously have a leak somewhere, check all hoses, the rad and the water pump for leaks. You could have a pinhole in one of the hoses for example.

Click to expand...

I thought that a small leak could be the culprit. Wish it would stop raining so I could check! Any advice on how to find such small leaks? Thanks for the quick reply

R222RWD said:

I thought that a small leak could be the culprit. Wish it would stop raining so I could check! Any advice on how to find such small leaks? Thanks for the quick reply

Click to expand...

Buy some ring automotive UV liquid and the torch.
example: bay of flea
230754744531

Cheers

neilly said:

Buy some ring automotive UV liquid and the torch.
example: bay of flea
230754744531

Cheers

Click to expand...

Not seen that stuff before, really handy. Cheers for that.

R222RWD said:

Not seen that stuff before, really handy. Cheers for that.

Click to expand...

Do not drink it...................Or stare at the light.................

Cheers

R222RWD said:

I thought that a small leak could be the culprit. Wish it would stop raining so I could check! Any advice on how to find such small leaks? Thanks for the quick reply

Click to expand...

You could do what neilly says or you could get someone to rev it to about 2000rpm while you look. The coolant flows at higher pressure under load. My pump hardly dripped at idle but at 2000rpm it gushed out. You might then see where its coming from.

neilly said:

Do not drink it...................Or stare at the light.................

Cheers

Click to expand...

"Don't look at the light!"
"I can't help it... it's beautiful..."

Mine is losing approx 1/2 litre every 1000 miles or so... worth checking the header tank and the cap...

Someone did post on here the other day, cannot remember who it was.

If you suspect the header tank cap, put the overflow pipes into a plastic bottle, secure it somewhere and see if it fills up. If it does then change your header cap.

Cheers

TBH, header tank caps are cheap enough, if you suspect it, change it. The rubber "O" rings tend to harden and flatten over time and start leaking pressure and coolant.

brian47 said:

TBH, header tank caps are cheap enough, if you suspect it, change it. The rubber "O" rings tend to harden and flatten over time and start leaking pressure and coolant.

Click to expand...

Funnily enough I've just ordered a cap, as you say they're cheap enough and worth changing. Will try and have a look this weekend and see if I can sort it, it's not too drastic, just don't want it to run out and the thing overheats :-S

You can also get pinholes in the thermostat housing