Major Coolant leak.

[Keechy]

Found a small puddle of coolant liquid under my 420R today prior to going out for a short drive.  On further inspection I found a slight leak on the hose from the bottom of the header tank so tightened up the jubilee clip.  I then started the car and took it up to 90 degree as I normally do to check the oil,  oil level fine so left the car for about 10 minutes, (car not running) when I returned there was a huge puddle about 2 foot round under the car, obviously shot out under pressure from somewhere but there was coolant everywhere so was unable to find where it came from.  There is some form of valve in the coolant tank cap that must serve some form of purpose but not sure what.  Any ideas?  Faulty cap maybe???????

[Jonathan Kay]

 

1. No problems with temperature before this?
2. No other work on it recently?
3. It might be worth starting with where you had to tighten the clip. Remove that hose and have a good look at it on the bench?
4. Then clean everything thoroughly to make it easier to find the leak if it's somewhere else. 
5. With that degree of leakage I wouldn't waste money on testing with coolant other than water until you've found out where it is. Except for protection against freezing.

Jonathan

PS: it might be worth changing the Subject line to attract a bit more attention.

[Keechy]

Hi Jonathan, when It had cooled down I toped up the coolant, ran it for a short while but turned it off as the header tank was bubbling and the water level increasing and was a bit worried what was going to happen.

[Jonathan Kay]

How did you bleed after the top-up, and is yours usually easy to bleed... or one of the other kind?

Jonathan

[Keechy]

I only put a small amount in the header tank just by removing the header tank cap as described in the manual, wasn't aware I had to bleed anything.  No temperature problems before this.  Parked the car after a ride out about a month ago then was going to pop out again today.  Is there not something in the coolant system that vents when the water gets so hot.  The fan cuts in perfectly when it should to drop the temperature.

[Jim 123]

What is the level (cold) in the header tank that you are topping up to? Is the "bubbling" you saw in the header tank coming from the coolant flowing from the return pipe that feeds back into the tank at the top? 

[johnpbransfield]

Sounds like a faulty expansion bottle cap. I had exact same symptoms earlier this year. New cap sorted it and I now keep a spare.

[Keechy]

Hi Level is normal when cold, as it gets hot before the fan cuts in the level of  coolant in the tank increases and very nearly fills the tank to the top.

A faulty cap could be the problem.

[johnpbransfield]

Mine was fine when cold, then same symptoms as you. Got my new cap from Rimmer Brothers as it was a Land Rover part (2009 Sigma)

[Keechy]

Hi John, sounds very much like you had the same problem, I think I will order a new cap and try that.  Bit of a worrying problem when your not sure if it works until you have tried it.  Extreme heat and pressure always a worry somethings going to give if not working correctly.