Cold bottom!! (hose!)

[dan7]

My mate's 16v kr, has recently had the head gasket, water pump, rad, thermostat changed. The bottom hose going into the rad is cold. ALL temp switches have been renewed. Hot air is coming into the cabin, so no signs of an airlock. Any ideas?

[Conker]

1) Even a brand new thermostat could be faulty. Ideally test it in boiling water before fitting.
2) Is the water pump squirting a good strong jet of water into the top of the expansion tank, that squirts even harder when the engine is revved?
3) Could still be an air lock - loads of posts on here about how to clear them.
4) Blockage in rad or water channel.

[Ben Lessani]

Did you let the engine get hot enough? If there is an airlock around the thermostat, it won't open. I'd let it run for a good 10-15 min's with the water cap off and keep an eye on oil temps and see if its any better.

Failing that, drop the bottom pipe flange, get the thermostat out and drop it into an old kettle or cup of boiling water.