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Discussion Starter · #1 ·
Hi There,

I have a problem with my rover, it is overheating to the extent of being virtually unusable.

When it is overheating, the top of the radiator, and the radiator top hose are extremely hot, but the bottom of the radiator and the radiator bottom hose are cold. I thought that the radiator must be blocked, so I replaced it, but I'm still having the same problem.

Interestingly, the heater sometimes blows cold and sometimes blows hot, even when the car is overheating. I believe that when the engine is revving the heater blows hot, and when it is idling the heater blows cold, though I could just be imagining it.

The water pump doesn't leak or make any noise. There is no oil in the coolant, and the car shows no other signs of head gasket failure.

a) Which way does the coolant flow around the engine?
b) How can I tell if the water pump is working?
c) Could it be the thermostat?

Would be grateful for some expert advice!

Thanks,

John.
 

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i believe it flows anti clockwise (looking down on the engine) the thermostat is a buger to get out..and the water pump is a pain to do....it could well be either of those things preventing to flow as my car did exatly this....one of my mechanic friends was on about the hg being broken and allowing exhaust fumes into the coolant but i told him to stop talking, even though the HG can blow in many many wonderful ways, the only way to test your stat is to take it out and boil it up.....as for the water pump the cambelt needs to come off so you will need locking tools etc etc
 

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As above, faulty thermostat or water pump. Sort it ASAP or HGF won't too far away.
Could be an airlock, but you say it was overheating before you replaced the radiator.
 

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Discussion Starter · #5 ·
Thanks for the suggestions.

I replaced the thermostat today, but the problem is still there. I'm going to try and replace the water pump - from the Haynes manual, it looks quite difficult.

The haynes guide says to hold the camshafts together with a homemade tool while removing the cambelt. Why not just mark the camshafts and put them back in the correct position when replacing the belt?


Thanks,

John.
 

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Thanks for the suggestions.

I replaced the thermostat today, but the problem is still there. I'm going to try and replace the water pump - from the Haynes manual, it looks quite difficult.

The haynes guide says to hold the camshafts together with a homemade tool while removing the cambelt. Why not just mark the camshafts and put them back in the correct position when replacing the belt?


Thanks,

John.
It's not as hard as the Haynes makes out, it just involves removal of all belts, engine mount and retiming. If you can do that then the pump itself isn't too difficult.

There's no need to lock the camshafts if you have timed up before removing the belt, but it helps greatly to lock the cams when retiming.
 

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Discussion Starter · #8 ·
I'm pretty sure it isn't due to an airlock. Each time I've filled it I've made sure there is no air, by ensuring the bleed screw is open and squeezing the top and bottom hoses with the radiator cap open to get rid of any bubbles.

Although I am not sure of the position of the heater switch while refilling/bleeding. I will bleed it again with the heater on before I change the water pump, which I intend to do tommorow.

Is there anything wrong with using zip ties to lock the camshafts? I would buy the tool, but I can't see anywhere that sells it being open on a bank holiday.

Thanks.

John.
 

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Lock them however you want. A piece of softwood of the correct size jammed in between does the same job.
 

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Discussion Starter · #10 ·
Replaced the water pump today. Same problem.

After much messing around we decided that water could not be passing the thermpstat, as it was scalding hot on one side and cold on the other.

So we took the thermostat out and put the car back together with no thermostat. The car works perfectly without the thermostat in the circuit.

Tested the new thermostat and it opens at the correct temparature. Tested the old thermostat and it didn't open very well.

Visually, the old thermostat is very similar, although not identical to the old thermostat. The temparature is the same 88 degrees. But the new one has an arrow indicating flow direction, and that direction is opposite to the direction that the water should be flowing through it. It is impossible to fit the thermostat the other way around as it doesn't fit in the housing. The old thermostat has no such flow marking.

The only rational explanation is that I was sold an incorrect replacement thermostat. I think I need to go to halfords with the thermostat, and see if they have other thermostats. At least my car runs now! If anyone knows anything about the different thermostats fitted to these cars I'd be greatful of your comment,

Thanks,

John.
 
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