Overheating X-flow

[Molecular--Bob]

I ran my engine for a long time at idle for the first time today while i was balancing the carbs, and noticed that i am not getting any hot water through to the rad. The engine was hot enough to kick the fan in but the rad was stone cold. The engine sat for a while with no water in it so the pump may be toast, but should i try changing the stat first. What spec of stat and pump do i need? I looked through tectalk but not sure i found anything definitive.

[andy couchman]

Try changing the thermostat first - you need a 74 degree unit (from Caterham or try a local motor factors). You'll also need a new gasket (the mult-purpose ones are fine or if you can't get one you can make one from some thickish brown paper using the old thermostat as a guide. Don't forget good quality antifreeze too.

 

The thermostats can jam in the closed position so it's worth drilling one small hole in the thermostat so that some water can always circulate. The car will take slightly longer to warm up but you're getting extra insurance in effect.

 

With luck the engine should be OK. Keep an eyey on things for the first few miles though.

 

I think that if the pump is damaged it'll screech. Otherwise they're pretty robust.

 

Andy

[Molecular--Bob]

Cheers

 

Sholuld Clarify, the engine was not running without water. The previous owner had taken off the rad and then not refilled the system. The guage only just hit the red before i noticed so hope all will be OK. What size of drilling would be required?

[Graham Perry]

Alternatively if its not that then an Airlock perhaps ?

 

A few years ago I helped my dad change the waterpump om a car where the impeller had sheared off the pump. The pulley turned as normal but no water circulated. That was a surprisingly tricky one to find as it wasn't the sort of thing you would ever expect

[Molecular--Bob]

Hopefuly not an airlock as i've done all the lifting the front and then the back, squeezed all the tubes and removed the heater, and used its tubes as a bleed point, reckon i got just over 4 litres in, does that sound about right?

 

I had heard that the pumps could loose their blades if left without coolant, so am a bit concerned that this is the case.

[Unclefester]

Got to be the thermostat wonked out. Should be perfectly ok. Throw it away for the summer, fit before winter......

 

Have you got a remote header tank/'overflow tank'????

 

NICE PLATE!!!

😬 😬here *eek*

 

Edited by - Unclefester on 2 Aug 2006 16:49:47

[ashaughnessy]

I'm a bit confused.

 

When you first ran the engine, did it have water in? When you say the previous owner had taken off the rad and not refilled, did you refill before starting the engine or did you start the engine, notice the overheating, then refill?

 

When you say things like "pumps can lose blades if left without coolant" do you mean they simply fall off while the engine is not in use if they aren't covered in water??? Doesn't sound very likely Or are you saying you ran the engine without any water and this caused the blades to fall off?

 

Anthony

[Molecular--Bob]

I rebuilt and refilled the cooling system before starting and tried to get as much air out as possible. Losing blades is perhaps the wrong description, but they tend to corode badly when out of the coolant for any length of time, and as a result you get very poor efficiency.