Consuming rad coolant

[festeroffroad]

Just a qik Q
Done about 250miles in my Surf 93' 2lte.
coolant level in overflow tank gone from just below FULL to just above LOW.
Engine is running clean. starts well. no over-heating. no leaks from cooling system.
a) Is this normal consumtion?
b) Is it a porus block?
c) Is it a Cracked head? seems unlikely tho as no others signs presant.
d) Or someting else?

any ideas ,thanks

[Silversurfer]

Just a qik Q
Done about 250miles in my Surf 93' 2lte.
coolant level in overflow tank gone from just below FULL to just above LOW.
Engine is running clean. starts well. no over-heating. no leaks from cooling system.
a) Is this normal consumtion?
b) Is it a porus block?
c) Is it a Cracked head? seems unlikely tho as no others signs presant.
d) Or someting else?

any ideas ,thanks

Had exactly the same prob on my Surf - eventually found a tiny pin hole on the rad header tank where it had been repaired from some previous accident damage - cured it with a soldering iron and some plumbers solder.
If not that then check pressure cap as it may be lifting at low pressure and blowing coolant out through the expansion tank.

[festeroffroad]

Had exactly the same prob on my Surf - eventually found a tiny pin hole on the rad header tank where it had been repaired from some previous accident damage - cured it with a soldering iron and some plumbers solder.
If not that then check pressure cap as it may be lifting at low pressure and blowing coolant out through the expansion tank.

yea, ill have a closer inspection when hot. should spot any small holes or lifting cap. Cheers