possible water pump issues

[grovesa]

Hi,

I have a 1955 series II moggy aka Horace. I seem to have a problem somewhere to with the radiator and or the water pump. When i run the engine, rev it up so it is hot, with or without my thermostat in, the water in the radiator does not seem to be moving in any direction.

I have removed radiator given it a flush out, some general orange rubbish came out of it but thats about it, also, i have cleaned out the hoses to and from the engine block to the radiator. I have had the water pump out as well, which i couldnt get the end nut off of. However i turned it by hand, no grating or wobble.

Can anyone help me as to what the problem may be?? I have been looking around but havent been able to find similar problems.

Thanks

[PSL184]

Is the impeller still attached to the water pump?

[mike.perry]

Is the rad hot at the top and cool at the bottom?

[bmcecosse]

There's nothing wrong......you won't see any movement till the thermostat opens. Unless the engine is overheating - Just run it!

[PSL184]

@Roy

so it is hot, with or without my thermostat in

[bmcecosse]

Oooops... must be pump impeller then.....

[mike.perry]

NB S2 water pumps different to M1000 pumps

[grovesa]

hi thanks for the fast replies,
The rad is hot at the top hose and is hot at the return hose at the bottom. but the actual radiator inbetween the two hoses does not feel warm at all.

When i took the water pump out, the impeller section which you can see with out removing the outer shell of the pump, is all intact and not got the much rust of rubbish stuck to it. Unfortunately i cannot get inside it as i cannot undo the nut thats holding the housing on that covers the felt and water seals inside.... well thats what the manual says is inside.

at the moment i am running the engine without the thermostat as the thermostat i have does not open up until well after 100 degrees. Due to this i though i should see water movement as there is nothing blocking the movement of water at the thermostat.

Thanks for your help

[bmcecosse]

Running without a stat is a NO NO. The water will just be circulating without going through the rad properly. You MUST use a thermostat. Inside the engine it will open earlier - how do you KNOW it doesn't open until 'well after 100 degrees' ??

[mike.perry]

I may have missed something Roy but I do not understand your comments about not running without a thermostat, it is only an option on the side valve when a water pump is fitted and the engine runs perfectly without it.
Surely the hot water would rise to the highest point (the 'stat) whether it was fitted or not. If the 'stat is closed water will not be able to enter the rad and will flow around the engine. If it is open it will flow through the rad, similarly it will flow through the rad if there is no 'stat to prevent it, although it will not reach the desired temperature.
Please correct my argument in words of one syllable.

[bmcecosse]

Can't comment on side valves matey - but on ohv engines you must use a stat or a competition 'blanking sleeve'' to get correct circulation. Mu own preference of course is to block off or eliminate the ghastly by-pass hose!

[grovesa]

I know it doesn't open till well after 100 degrees as i have heated the thermostat, as i thought this may have been the first problem. so i now know the temperature when it opens.

Also, running without a stat is not a no,no as you so patronisingly put it, as the idea of a thermostat is to increase the water temperature surrounding the engine, and only once it is at an appropriate temperature allow the water from the rad to mix and go through the engine block, which allows the engine to heat up to temperature quicker, without a stat it just takes longer for it to heat up to perfect running temperature.

but thermostats aside i was actually asking about the water pump, and the movement of water in the radiator. Do you have any hints as to the where the problem lies?

[mike.perry]

If the rad is hot at the top and bottom but cool in the middle it suggests to me that the core may be blocked, preventing water from flowing through it properly. Try a cooler stat as the one you have is opening at far too high a temp. Also what pressure cap are you using, 4lb is correct for a Minor

[bmcecosse]

How did you heat the stat 'well after 100 degrees' - you can only boil water AT 100 degrees! It very much IS a NO NO to run without a stat - the water short circuits and doesn't cool the engine evenly - but, what do I know ? I've only been working with competition versions of the A series for 40+ years...... Carry on as you are - it's your engine. My view - there is nothing wrong - just put in a new stat if you feel you must........

[grovesa]

my radiator cap is a 4lb one, but its the original one, so maybe time to replace that, thanks for your help!

[bmcecosse]

I suspect nothing to do with the rad cap unless water is overflowing past the cap?

[kennatt]

you may be worrying unduly, the test is, Is the engine overheating,if not then leave well alone.

[bmcecosse]

The problem here is very simple - either the radiator is choked with silt - or the pump is not pumping. The pump has been checked - ergo - it IS a radiator problem.......