Cooling fluid loss

[PaulShaw]

Hi guys
i started my Stag yesterday and left it on tickover for about 15 mins, then drove off, after a couple of miles it overheated, I let it cool down and found half the coolant had gone, once I got back home I noticed the fluid was on the road outside my house, it looks like it came from the expansion tank, I topped it back up and took it for a run and it was fine with no sign of any leaks.
Any advice would be greatly appreciated, it went to the red so I think I had a lucky escape.

[PaulShaw]

Just to add, it has an additional electric fan that had kicked in, there was no sign of coolant in the engine oil, I am new to Stags but have noticed over time that sometimes small amounts of coolant has come out of the expansion bottle before

[wilf]

It might be that your thermostat is sticking - could be worth changing that. And if not done recently, a cooling system flush.

also, to set your mind at rest about possible head gasket failure ( they don't normally let water into the oil ) then do a block test - a simple chemical check that tests for combustion gasses in the coolant.

You say "expansion tank" - is this the original plastic bottle? Worth checking it is still airtight around the crimped neck.

[PaulShaw]

Thanks Wilf
where can I get the kit for a coolant combustion check?
it is the original expansion tank, I have had the car 7 months and noticed coolant coming from the tank a few times

[wilf]

EBay - just search for "block tester kit", they are under a tenner.

If your expansion bottle is not 100% airtight, then it will overfill with coolant and overflow each time the engine warms - as the pressure/vacuum necessary to get water back from it as the engine cools, into the radiator is lost.

[PaulShaw]

Thanks, I might look at converting to a header tank

[Roy_S]

There is lots of info on here about header tanks, electric and external water pumps etc. Some prefer to keep the engine as standard and others alter the cooling system in varying degrees, personal choice.

Mine was made up when the pump failed and dumped all the coolant out, that and the fact the pump was at the top of the engine so it didn't take much of a water drop to stop circulation. Now run external Ford water pump (see Stagdad on here) came as a kit, plus I added a Volvo header tank that has a level warning plus being clear you can see the coolant level at a glance.

[Peter707R]

I personally would not let the car idle for 15 mins from start up - the engine relies upon oil being thrown up into the bores for lubrication. Best to start and drive away as soon as possible - push in the choke once the engine is able to run cleanly ( I find a small amount maybe needed at junctions to avoid stalling but otherwise choke fully in after less than 1/2 mile).

[PaulShaw]

Thanks guys

[PaulShaw]

Hi Roy
in your experience where are the best places to connect into the cooling system for the header tank feed pipe and the expansion pipe?

[PaulShaw]

I see EJ ward use the top radiator hose connection and the existing expansion pipe that comes off the top of the radiator copper tube

[Roy_S]

Hi Roy
in your experience where are the best places to connect into the cooling system for the header tank feed pipe and the expansion pipe?

It all depends on personal choice, some like to keep the original overflow pipe.

For me I wanted to be able to get any trapped air out of the system, the original overflow pipe enters the rad on the cold side and runs a little way down into the rad so air can sit trapped above it.

I had my rad altered with a new air bleed in the neck of the rad and a new 20mm inlet fitted half way down on the same (hot) side. The header tank sits up next to the suspension strut and both pipes go from there straight to the rad. To fill I can do this from the rad and then refit the filler, start the car and run it, as air makes it to the neck of the rad the small hoe off to the header tank picks it up and the lower 20mm hose allows more water in. As this is the first run filled, I'll do this with the header cap off to top up as needed until no more air comes out (heater set to hot so no air trapped in there).

I've had to empty and refill a few times due to a faulty VC, it usually needs a few top ups after the first few runs as any stray air makes it way out, but as the header tank is clear it's easy to see. I've also got a water level sensor in the header to connect later on to feed the Stag water lever paranoia....

Below are the before and after pictures of the rad, it's the original one, I had it tested and the two new inlet pipes fitted locally by Bagshot Raditor Services, he always seems to have Stag rads in there...
IMG_5736.JPG IMG_5775.JPG

Below is a shot of the header tank in place during a trial fit as I moved the alternator so needed to make sure the piper cleared. I'll make up a metal bracket to both to the suspension strut to keep it in place.
IMG_5766.JPG
As I said personal choice, but I like the ability to see the water level quickly before I go out, and this keeps the header tank pipes all on the same side of the rad so no risk of bridging the hot & cold side or water pump pressure using the header as a bypass.

[DJT]

This is a contentious issue as many people have differing opinions. IMO (there you go ), the ones sold by 'specialists' are too complicated. I have been running with a Volvo tank for over 50,000 miles; 46,000 on my current Stag. This is plumbed in similarly to above, with a 20mm stub in the LH side tank and an 8mm stub just below the brass filler plug for air bleed. This was deemed perfectly acceptable by a well respected former member of this forum who many will remember for his Kingpin articles in the SOC magazine, which is good enough for me. My first tank cost £5 from a scrappy. I replaced it 2 years ago with a brand new one, and a brand new float switch, for around £45.

[Roy_S]

It was you that pointed me down the Volvo header tank path

[PaulShaw]

Thanks guys, some useful info to point me in the right direction, can't wait to do the mods