Boiling Over Mi16

[arwel 43 2 Cars]

Having a proper fun time with this f***er fair play. Whilst the on going dying problem is still being investigated it also decided to boil over. We've taken the thermostat out and it's still doing it. No temp gauge reading on the dash either even though we know it's working. Any ideas or do I just assume it's cooked the head gasket?

[dcc 855]

Whats your definition of boiled over. Have you got the multiplugs? Is the crank sensors in tidy? Do you have correct sensor plugged in for coolant? Did your fan cut in? If not was radiator warm? Has it had a new belt and water pump? Do you run heater matrix? If so did you get either hose warm? Did the air in cabin blow hot? Does your expansion tank recirculate water from the radiator? Have you done a compression test? Anything different with the engine from this car to the previous?

[arwel 43 2 Cars]

Whats your definition of boiled over. Have you got the multiplugs? Is the crank sensors in tidy? Do you have correct sensor plugged in for coolant? Did your fan cut in? If not was radiator warm? Has it had a new belt and water pump? Do you run heater matrix? If so did you get either hose warm? Did the air in cabin blow hot? Does your expansion tank recirculate water from the radiator? Have you done a compression test? Anything different with the engine from this car to the previous?

Trying to bleed it with cap off and it's just pissing it all back out through the header tank.

Coolant sensors are in and working as we tested them. No fans as their only on a switch. Rad gets warm and all the pipe work gets warm too. No warm air in the cabin as in typical French way the blowers have stopped working. Compression test is next on the list. Engine is exactly the same in this one as the last one apart from a different rad.

Edited August 17, 2015 by arwel

[arwel 43 2 Cars]

Or am I being thick and not putting the cap back on quick enough and it's then blowing all the water out as its getting warmer?

[dobboy 231 2 Cars]

I wouldn't have thought you could bleed it through the header tank.... Not with a full bottle anyway.

 

Anytime i've bled mine (GTI6) from filling from empty there has been minimal air.

 

I previously had a similar problem and it was my cap that was under rated.

[dcc 855]

Well, its an expansion tank, you dont want it to be full when cold (water expands when heater). You ideally want it just below the join mark on the phase 1/1.5 bottles. You are ok in thinking it should self bleed with the cap off, thats how I usually do mine, use the bleed screws to be sure though.

 

How much water actually comes back through? Do you get air bubbles?is it water youre using? Is it clean or murkey and cloudy?

[dcc 855]

Xu10j4rs engines run a different water system to an xu9 16v. Hes having issues prior to fitting cap. Hes also rmovef the thermostat so bleeding from exp. Tank will be fine.

 

I know you've removed the thermostat, but have you drilled a small hole in the thermostat to aid with bleeding air? If not its worth doing and fit it with hole at top.

[arwel 43 2 Cars]

Bubbles is how it starts and then it pretty much empties the expansion tank. It's all clear water, no murkiness or anything. Worth trying it again and pop the cap back on sooner and see what the temp gauge does?

[dcc 855]

Sounds like its pressurising between waterway and a cylinder.

 

Temp gauge runs on resistance. Should show something prior to heating. Ill facebook you

[Tom Fenton 1,541]

It does sound like head gasket to me. I've had 2 Mi's do this to me. With it totally cold with water in and the cap on tight, squeeze a rad hose and hold it squeezed then get someone to start it. If you can straight away feel the coolant system start to pressure up then it is head gasket most likely.

[arwel 43 2 Cars]

Problem appears to be sorted. Did a pressure test and a compression test and all looked fine. Decided to bleed the system again and pop the cap back on. Temp gauge now working after being put on the wrong sensor and all seems normal again. So one problem down, one too go.