I might have broken something ... not enough water and more

[Captcol]

well today I decided to do some work on the truck and in doing so I saw that the radiator tank had no water ... crap .... then I opened the cap and it wasn't full either ... .double crap ... drove 250ish kms since monday morning. Quickly refill with water, about 500mls in the radiator itself.

Run the truck for awhile, pull the radiator cap off before it gets too hot and there is foam in the neck of the radiator, put cap back on. After the truck has run for awhile and the needle goes up abit turn off and let cool, check water - tank still on max, radiator about 200mls down, no foam.

Thinking to myself crap I hope I haven't done a head gasket, while running I decided to pull the oil cap off and see if I had any blow by, well no fumes but the engine note changed and there is defiantely air fut fut fut futting out just no smoke, so no idea what that means, oil drops sprayed out a bit as well. Standing on the drivers side there is a high pitched metallic clicking noise as well that can not be heard from the passenger side.

So my first questions is have I f#cked anything?

and secondly is the fut fut fut normal?

on a side note I removed the egr solenoids and traced the vac lines, mine t's between the block and the air con pump and I have another t on the other side of the block that goes to the solenoid for fast idle and another pipe that heads to the back of the engine bay and connects into a metal pipe that disappears under the passenger side. So I have blocked the pipe off above the aircon pump and then removed everything else for the egr.

Please post immediately if it is good news, and post even sooner if it is bad news, I have to drive home on saturday

[geeves]

The foam occurs because the waterpump is cavitating when the water is low. This is to be expected as long as it clears. To test for a head get a length of clear tube about the diameter of the radiator cap and place in the hole and fill to the top. With the engine running any bubbles will be obvious.
Cant be sure about the noises but people do get more sensitive to noises when something else happens They sound fairly normal but need more info to be sure.
If you didnt overheat and didnt top it up with cold water when it was hot you are unlikely to of done damage but you do need to find out where the water went. A visit to a local mechanic will give piece of mind

[turnturn]

The metal pipe that disappears under the passenger side may go to a small vacuum storage tank mounted to the chassis/body about under the passenger seat. I have one on my 96 Mu. I think they were added when the Shift on the Fly (SOF) system was added.

[Captcol]

cool, will find some pipe tomorrow, I am going to replace the radiator cap as well, this morning the rad tank was down about 200 mls, this afternoon was over max by about 200mls and tonight after an hours drive and 3 hours cool down was in the middle of the two and when I opened the radiator it either sucked air or vented air so figure better safe than sorry.

[turnturn]

If its any help/consolation my radiator (not header tank) is always a bit below being completely full when checked (cold). Maybe about 1/4 the volume of the top tank.

[geeves]

That is caused by the second seal on the cap being faulty or a small leak allowing air back in. The second seal at the top of the cap allows the cap to suck water from the overflow tank

[Captcol]

Right have replaced radiator cap now, tried the tubing trick, small bubbles from cavitation as above I expect, I had a couple of large bubbles but I expect this was due to the thermostat opening after that no more bubbles so hopefully the head gasket is intact.

Checked tapet cover again, definately some pressure there but no fumes so thats good as well

[geeves]

Just thinking about the amount of water you put in 500ml may be a lot in a mini metro with a K series engine as the cooling system on them only held 2.5 litres but in the bighorn its nothing. I put the fan through my radiator and by the time it ran hot (half guage on the flat) it needed 2 litres to refill. Then another litre and a half 30 minutes later then this much again before I got home. There is a reason I always carry 6 litres of water