Having a bad week, bought a Triumph Stag, drove all the way home from Stoke with no real problems (280 miles), took my mum out for a spin round the block and blew the head gasket.......up to my neck in oily bits at the moment.

Any way driving along the motorway the other night in the FFRR at 70ish and all of a sudden large cloud of white smoke out the back and temperature gauge creeping alarmingly toward red...pulled over, 11pm so a bit dark, and see the top hose for the radiator has blown off. It failed at the end nearest the engine by the rubber hose coming off the plastic bit, its held on by some kind of shrink fit metal band not a jubilee clip. Get recovered back to house and next day AA come round and do temporary repair by re fixing hose with a jubilee clip, refill system and bleed it.

After running car for ages, heater wont come on and the top hose is hot (85C) and rock solid and the lower rad hose is relatively cold, 30C or so. AA man not happy, thinks its thermostat and sends it to garage. I get a call from mechanic and he thinks pressure build up in top hose is excessive so will change top hose and thermostat and see if that cures it.

Anyone have any thoughts.

PS it's an independent who is Land Rover trained and honest as the day is long so not overly worried but would appreciate some thoughts.

Thanks in advance guys, bit p$1£ed off at the moment with 2 sick V8's and having to get dropped off at work in the back seat of a Corsa!!!!

oh dear, a different car from my 1999 P38, but this is how it started and three engines later it had to go for scrap  No body told me there would be days like these

L Reg dark purple/burgundy sort of Disco
R Reg very red disco
Bright Silver disco TD5
Sort of bright girly powder blue disco TD5
Gone (a while back) 1999 P38 4ltre Autobiography. 13 miles to the gallon, 10,000 miles to the engine
Gone MY06 RRS HSE Rimini Red
Gone MY10 RRS HSE Purple
Gone 2007 TDV8 Vogue OF Stornoway Grey (In Love again)
2011 4.4 TDV8 Vogue Baltic Blue
MY66 VOGUE TDV6 3.0 Red

Check the water pump. The OEM one has plastic fins so if the bearing goes, all of the fins disintegrate and the pump becomes ineffective. Mine added the bonus of throwing the belts off.

You need to remove the fan and cowling (LH thread), radiator (easy), EGR pipe which goes from side to side across the front of the pump.

I also removed all of the hoses and flushed them through then backflushed the block and gearbox heat exchanger to try and find the elusive missing plastic fins - Found a couple but not all of them.

While you have it in bits, depending on the mileage, consider replacing the radiator. If you've done more than 60k miles, its probably lost its efficiency for cooling the gearbox and will soon cause problems.

If you get no heat from the heater then that sounds very much like an air lock. Too much air in the system will enable the coolant to expand/boil which will then compound the issue and then cause your over-pressurization issue.

I agree with above, check the coolant pump, they are not expensive to replace, I paid under £150 inc parts and labour. HOWEVER the heater has an auxiliary pump so if the main pump had failed the heater would actually still work, but the matrix is obviously empty. With the ign on and the cap off the header tank you should see water flowing from the aux pump.

I would drain the coolant completely, then re-fill, making a note of how much water goes back in, then you know whether or not its full.

The top hose coming off could have been due to a failed clip rather than too much pressure. It's important to get cause and effect the correct way round. ie a head gasket will only fail when an engine overheats due to lack of coolant, it doesn't cause the lack of coolant in the first place and unless the root cause is found then you will replace the head gasket in a few months time. 

DeltaC wrote:

While you have it in bits, depending on the mileage, consider replacing the radiator. If you've done more than 60k miles, its probably lost its efficiency for cooling the gearbox and will soon cause problems.

Nappler wrote:

DeltaC wrote:

While you have it in bits, depending on the mileage, consider replacing the radiator. If you've done more than 60k miles, its probably lost its efficiency for cooling the gearbox and will soon cause problems.

I've been thinking about replacing the rad for piece of mind myself when the car is next in for a service, any idea how much they are?.

£160-£200

http://www.island-4x4.co.uk/-c-144_2408.html 

dan_uk_1984 wrote:

Nappler wrote:

DeltaC wrote:

While you have it in bits, depending on the mileage, consider replacing the radiator. If you've done more than 60k miles, its probably lost its efficiency for cooling the gearbox and will soon cause problems.

I've been thinking about replacing the rad for piece of mind myself when the car is next in for a service, any idea how much they are?.

£160-£200

http://www.island-4x4.co.uk/-c-144_2408.html

Thanks for that Dan, much appreciated , the car has been fine since I've had it but am thinking a rad change and gearbox oil change might be a good idea next time I get it serviced, prevention being better than cure and all that.

Mine was genuine, £120.
Makes sense to get all of the hoses and the two belts while you are in there though. Lower hose comes complete with the thermostat and housing. They are a piece of cake to fit - clip on, clip off.

If I was doing it again, I'd fit a pre-emptive water pump because I think my new belt was too much for my old pump.

Thanks for all the input guys, just got it back with new top hose and new thermostat. Mechanic seemed pretty happy with it. Heater blowing really strong with hot air although aircon not blowing anywhere near as cold as it was the other day. Also centre dash vents only blow cold when wheel turned to 3 blue dots, any other position it's hot air even with temp dials turned all the way to minimum...confusing!

Reassuring part at the moment is that temp gauge is bang in the middle even after sitting idling for 30 minutes and appears no head damage. He stuck a compression test on coolant system and it held 1.5 bar for the 30 minutes with no leaks.

Will do a rad and water pump change before winter as system has had 2 flushes now in 6 months as had to change alternator at Christmas time there.