Water Loss

[WilliamPike]

I confess firstly that my car is a 1948 MGY with an XPAW engine (modified to fit) but this question should be a general XPAG (prior to MGTF). My car uses water prodigiously (two litres in 10km) It appears to be pumped out of the overflow pipe. No exhaust gases are present in the water and the engine otherwise peforms well with no water out of the exhaust. I have pulled out the radiator and had it professionally flushed, and put cleaner through the block etc. They did not pull the rad apart. My guess is that te rad is still blocked enough for the water pump to push water out of the oveflow. Since removing the rad again isn't that easy, are there any other thoughts on the matter please? Thanks Bill

[Steve Simmons]

Hi Bill, my first thought would be that the radiator is never truly full, and if filled to the top it will dump a good amount of water before it finds its level, and then stays there. Two litres sounds like a lot, although I confess I've never measured how much it takes to fill from the normal operating level to completely full. So I guess my first question would be, does the car run hot? The radiator would have to be severely blocked to not allow water to drain fast enough. Another question would be, does the water continue to pump out until the top of the tubes are no longer submerged? I've found the "normal" level to be around an inch below the bottom of the filler tube. If the tubes are exposed then there is definitely a problem.

Regarding cleaning (and pardon me if you know this already), radiators can be boiled out but the only way to know for sure that it's truly clean is to remove the top tank and rod it out. If that's done then it will be good as new and you can put it out of your mind.

[WilliamPike]

Thanks for your reply Steve,

Yes water level goes well below the top of the radiator core. The previous owner ran the car out of water with a different engine so I suspect the radiator. I was playing with it today and the water level slowly rises and runs out but when one revs the engine the level drops. I imagine that the extra pull from the water pump might pull it through although I would have thought that the extra flow would have pushed more water out. ? Mysteries!

Cheers

Bill