Boiling over at 3000rpm...

Hi All,

A quick Sunday night puzzler for you all…..
My Discovery 2 TD5 auto is really overheating if I go over 3000 RPM for an extended period i.e. up a steep hill. Now I have only just bought the vehicle and have had to do some work on it which I’ll list but this problem has really got me stumped!
I replaced door locks, wiper assembly, auto gearbox oil, both oil filters, fuel filter, air filter and top branch hose (the one with the air bleed valve) and the dreaded WATER PUMP.
I’ve been bleeding the coolant hose and holding the expansion tank above the height of the bleed tap until only fluid comes out. Next morning (or on the road when it over heats) I can still get more air out of it!
I’m pretty sure that the head gasket has not failed as the expansion tank doesn’t bubble and there is no oil in the coolant or oil itself. Overall the engine runs like a dream and doesn’t ‘hunt’ however it seems to need to rev high -2000rpm for 15-25 MPH- but perhaps that’s just the way the TD5 is set up…
So, do I have a leak somewhere? I haven’t seen any water on my drive.
Is the radiator shot? My 300TDi died this way
Have I done something wrong with the AUTO fluid change?
Could the heater matrix be at fault? The heating is intermittent?
Or finally does it just take ages to get all the air out of a system that's been drained?
Any thoughts before I bite the bullet and take it to a dealer would be greatly appreciated

overheating or boiling over?

If boiling over would suspect the head / head gasket, if just overheating then could be clogged / knackered rad.
Do you run it with the heater full on? good to do this to ensure full circulation and bleeding.

I'm having similar problems. No heater for ages, then overheats and looses power. This condition I've realized is due to lost coolant. Obviously no heater as no water flowing through the heater matrix and hence the subsequent overheat. No idea why/where I'm loosing coolant of course and can see no sign of a leak.
No flow would suggest the pump but of course, it is not as simple as that. After topping up with coolant, the heater starts working again and reaches normal temp (gauge up half way) and all seems fine again, except I now have reduced power. Now it could be coincidence that the power loss problem has emerged at the same time as I'm experiencing coolant loss issues but I don't suppose I'll be so lucky. Having trawled through LZ I fear I may have an HG/cracked head failure. there is no sludge under the oil filler cap or other visible sign of coolant in the oil, nor of oil in the coolant.
Any ideas that might fit my symptoms?

Hi Folks,
Yes it is boiling over and loosing power in exactly the same way as 'Clifford' describes with his. So, where is the water going? if not in the oil supply then into the cylinders? surely this would impede the engine working at all!
Also, the lack of power could be 'limp mode' because of the high temperature?

Also, I have been running the heater on full but even then it only works occasionally i.e. when there's water in the matrix

heater not warming up must mean airlock surely?

if the radiator is okay-cracked head with the related symptoms mentioned.

head needs heating while pressure tested to reveal crack, ask Ratty

Thanks Fanatic.
So the vehicle behaves and drives fine and at normal temperature if I keep to 50-55 MPH is that still a cracked head?

Also, what's a good test for the radiator other than removing it?

Hi All,

I've had a look through all the forums and I reckon it's the HG that's gone.
I'll book it in to Rogers in Bedford, a local LR specialists. They should be able to test the radiator and HG.
Anyone know what they'd charge to replace the head gasket?

i had a cracked head on my passat... no issues at 70mph, but do more or use full power and it would steam all of the water out of the header tank within a few miles

Giles Clayton said:

Thanks Fanatic.
So the vehicle behaves and drives fine and at normal temperature if I keep to 50-55 MPH is that still a cracked head?

Also, what's a good test for the radiator other than removing it?

Click to expand...

Radiator should be hot all over, hoses not rock hard.

Check expansion tank not cracked and try new cap.

That said 50mph plus on boost overheat is a known cracked head symptom along with heater blowing cold.

Forum member ratty has experience of this

Ps was iit a private seller or dealer?