Coolant loss - DSE

2001 - 81k miles DSE well serviced.

I've noticed that the coolant level will drop in the expansion tank below the cold mark by about 2" and seems to stay there. I top it back up with coolant and it will slowly drop over about 1000 miles or so.

There is no contamination in the engine oil nor in the coolant, both look perfect in colour, etc. The engine oil level does not rise and there is no 'mayo' to be seen anywhere.

No obvious signs of leaks and no excess condensation in the car.

Is it likely to be a slow leak from a pipe somewhere, or perhaps a new expansion cap is required, as I've heard a few comments about changing it!

Maybe someone has had a similar issue?

Check for wet carpet in the drivers footwell

O-rings could be the culprit - leaking radiator, hoses, waterpump and of course headgasket.

keep us posted...

What o-rings? Something to do with the heater matrix?

I'm fairly certain the head is not leaking, it just does'nt seem to fit any other symptoms I'd expect to see.

It's been doing it for at least 6 months now and is not getting worse. Just a very slow loss of coolant, say 250ml per 1000+ miles.

I'll check the carpet for dampness, but there is no moisture in the car at all.

The fluid has to be going somewhere, either you have a leak or something more serious like a head gasket. Does it run at the correct temperature?
"O" rings on the pipes that go to the heater matrix are a common cause of slow coolant loss.

Car runs fine and temp is always in the same place when at running temp, never seen it different, but I'll keep an eye on that.

....Just been outside and there is a dark area on the carpet to the left side of the clutch pedal. I put my hand up behind some plastic and managed to grab a few wires that were WET!

Thanks Datatek, looks like it's the matrix then. Did'nt think it was the head.

Whats the repair then?

Simon1975 said:

Car runs fine and temp is always in the same place when at running temp, never seen it different, but I'll keep an eye on that.

....Just been outside and there is a dark area on the carpet to the left side of the clutch pedal. I put my hand up behind some plastic and managed to grab a few wires that were WET!

Thanks Datatek, looks like it's the matrix then. Did'nt think it was the head.

Whats the repair then?

Click to expand...

It's not the matrix, it's the "O" rings, there is a good explanation of what is involved on www.rangerovers.net The "O" rings are peanuts, but changing them is quite a big job, do it Land Rovers way and you are talking a couple of days, the quick way is a couple of hours if the pipe retaining screw comes out OK. I haven't done it yet but it's a job I have to do when it gets warmer

check it out on rangerovers.net.it made my repair dead easy and get t replace phillips screw head as an allen head from memory its an m5 thread i think ,

Well when I said matrix, I obviously meant that's the area I needed to repair.

I recently replaced the pipes on my oil cooler and they have o-rings at both ends. So I guess it will be a simliar carry on at the matrix end.

Thanks for the replies, I will check it out and look into doing it when it's warmer.

Heater Core O-Ring Replacement

Hmm, defo a Spring job. Looks like fun!

Parts:

Range Rover P38 Heater Core Temperature Sensor £18.99

O-rings STC 3262 x 2 £2.49

I've decided to replace the heater core temp sensor as recommended by the guide above as my book symbol appears for no apparent reason, so it may fix that too with a bit of luck.