diagnosing a blocked radiator??

[jamesheath]

I take it all back!!!!

I figured I might as well fit the rad back on and give it a try, as I don't have a replacement yet.
It is very clearly improved, and is good enough at this time of year:

   


As a guide to others, if you have any signs of oil in the water, I would start with water based de-greaser (I used GUNK) - I think this did the most work improving things.

The rad still needs replacing I think, as there are a few leaks (hard water for a while may fix those), and it's unlikely to cope in the summer (the water is reaching 80 odd with moderate uphill work), but it was good fun experimenting!

[jamesheath]

A further note - for others working on their rads.
After a couple of hot runs, the Brighton water (which is incredibly hard) has pretty much sealed all the leaks.
I'm going to do one more run and then swap to distilled water (collected from the tumble dryer) and antifreeze.
I'll then see how long in to the summer the rad holds up!