Hi, we have an R reg 1.7 Puma and have had a problem with coolant not flowing round system. I have deduced its coolant flow problem as the i have removed the thermostat and replaced the water pump. With car at fast idle for 5 mins or so the radiator is stone cold but the engine very hot, the temp guage fluctuates from mid way up to hot and back down and when i felt the top rad hose (near to the engine) i could feel water boiling and bubbling from within the engine.

With the top hose off the radiator and the car running no coolant comes out the rad even though the rad is full of coolant and also no coolant is reaching up to the heater matrix (i've taken hoses off and they are dry).

If I take the hoses off the radiator and pour water in the top it flows out the bottom, likewise on the engine- water flows through the block indicating no blockages.

Can someone help as i'm pulling my hair out as to what it could be.

Rob

That is a strange one.

Without the themostat fitted you should get some hot water from the engine to the top hose on the rad.

The only thing I can think of is the water pump is not circulating the coolant.

Are you sure the water pump is not broken and being driven?

hi jock0909, cheers for your reply.

Yes the pump is ok, i fitted a new one when this trouble started, with the thermostat out i can feel the pump turning when i turn the pulley. The water jacket isn't blocked , nor is the radiator as water flows through them. I'm thinking the headgasket could be at fault but the it doesn't add up.

prior to this happening my girlfriend said that the car would blow cold air out the blowers for a minute or two then go back to hot. she said it done it two or three seperate occasions- could this be a clue?

It has got to be an airlock - it's the only thing that makes any sense.

It's possible the head gasket has blown (or a cracked cylinder head) and is causing the airlock but I am not convinced of this.

When you refill the coolant system, run the engine at idle and make sure you bleed the system of all air (dont replace the cap) and switch the blower fan on and the temp control at hot.

squeeze all the hoses and keep working round all the hoses until the heater is blowing hot air and all the hoses are all hot.

Keep us posted how it goes.

It has got to be an airlock - it's the only thing that makes any sense.

It's possible the head gasket has blown (or a cracked cylinder head) and is causing the airlock but I am not convinced of this.

When you refill the coolant system, run the engine at idle and make sure you bleed the system of all air (dont replace the cap) and switch the blower fan on and the temp control at hot.

squeeze all the hoses and keep working round all the hoses until the heater is blowing hot air and all the hoses are all hot.

Keep us posted how it goes.

I have the exact same problem with mine! I recently bought a puma for a little run around! Initially it was advertised as a blown head gasket but when i looked it was a blown heater pipe! I have run it now for a week and it has started doing the exact same thing! There is definitely an air lock in the system somewhere and I think it might be the head gasket! Can't think of any thing else! Have you got the common signs of a blown head gasket? Emulsified oil White smoke etc?