water flow

Post by **sidsmith** » Mon May 05, 2008 7:21 pm

I think I'm right in saying the water flow goes from the top of the radiator through to the bottom and then into the engine and then back to the top hose to go back down again. there fore with the engine running on tickover shouldn't I be able to feel the water going through the top hose into the rad'
My top hose feels empty and i'm wondering if that is the problem I am having with the temp' gauge going off the dial after 10 mins'. So if I take the top hose off and then turn the crank with the starting handle would that prove that there is water flow around the system and coming out of the thermo orifice or do you think I am barking up the wrong tree.
"mungo's"getting really hot and bothered.

Post by **bmcecosse** » Mon May 05, 2008 7:31 pm

Well - if the thermostat is open, hot water will flow through the top hose - which should be 'full' all the time. Maybe your thermostat is stuck shut ? I would take it out - and fit a 74 degree stat for the summer. Also worth flushing the rad and block with garden hose - may be even some rad flush (or drain cleaner) - but don't leave them in there too long.

Post by **sidsmith** » Tue May 06, 2008 11:52 am

well I have just stripped the rad out and back flushed it and top flushed , from the top flush the water comes belting out , from the bottom to top flush the water comes out but not the same extent as the other way, so I think it should be alright.
I then took the therm,o' housing off and took the thermo out and water flows top to bottom and vice versa,
The thermo is a 82 deg' one so I am just of to buy a 74dg as suggested, If that doesn't cure the problem then would you say the water pump could be the culprit bearing in mind that the water must be flowing through it to go top to bottom etc.
sid.
what about if I try to run it without the thermo to see if the water is actually circulating on tickover.

Post by **Willie** » Tue May 06, 2008 5:51 pm

Without the thermo will certainly give you a much more forceful flow so that you should see it via the rad filler but do not run for too long without the thermo. 'as normal'unless you fit a blanking plate. It is not unknown for the water pump impeller blades to have rotted away.

Post by **bmcecosse** » Tue May 06, 2008 7:03 pm

Nevre seen rotted impeller blades - but of course it is a possibility. 4 Bolts take it off to investigate.

Post by **d_harris** » Tue May 06, 2008 8:14 pm

I have! Just taken that pump off. Then again the whole cooling system was gunged up and horrid and the car hadn't been run since 89......

Post by **Packedup** » Tue May 06, 2008 8:23 pm

bmcecosse wrote:Nevre seen rotted impeller blades - but of course it is a possibility. 4 Bolts take it off to investigate.

I've seen some pretty tired but not rotted cast ones, but the pressed steel pattern ones seem to rot through without too much difficulty. Almost like they're covered in underseal ;)

Post by **bmcecosse** » Tue May 06, 2008 8:51 pm

Which is why you should a) use original parts and b) use antifreeze all year round.

Post by **sidsmith** » Wed May 07, 2008 12:26 pm

On to the next stage of the developement, after visiting the moggy shop in Oldbury the assistant said that he had a customer who had the same
problem and done everything that I have covered.
And the thing that he did which seemed to cure the problem for him was to take the head of and give it a good clean and flush,
but before I do that I will take the connecting hose off if I can that joins the top block to the bypass hose and see if that is all gunged up, if it is then the head will have to come off. I'll keep you informed.
"mungo"

Post by **rayofleamington** » Wed May 07, 2008 5:33 pm

Nevre seen rotted impeller blades

I've seen one with absolutely no blades left! The car ran hot but cooling system 'seemed' to be working but the heater didn't give anything out at all on cold days.

When removing the top hose from the radiator, the pump did not push any water through it at tickover - when the engine was revved up the pump 'stub' managed to do a bit of work and pushed water through the top hose.

As for a blocked bypass hose - that's not really going to tell you much. It's pretty common to find a blocked bypass on a tired engine, especially if it's not been well maintained. Antifreeze and regular flushes are essential in the long term to limit the corrosion and sludge in the cooling system.

Post by **sidsmith** » Fri May 09, 2008 11:25 am

another installment in the saga. I finished up taking the water pump off and the protruding small piece that connects the small hose to the cylinder head was blocked solid as was the small port. which stopped water flowing through the head. Also there was a small fragment chipped off the small port and I think it is now flowing round the system. The end result is that the temp' gauge after running for 10 mins doesn't show overheating.
Now the only other problem I have to sort out is that after the car was running for 10 - 15 mins it suddenly cut out. There is fuel going to the carb', there is a spark at the points and also the plugs, has any body any ideas what to look for now ? HELP.
mungo.

Post by **Willie** » Fri May 09, 2008 8:41 pm

If it has only cut out once then it is too early to diagnose a fault, if it has cut out several times at roughly the same time then it could be heat related breakdown of a component ( the coil is favourite) or, perhaps,
an airlock in the tank(release the filler cap and listen for a hiss as you do so) although you say that fuel is present. if you decide to change the capacitor in the dizzy or the coil etc then change one item at a time or you will never know what the fault was!

Post by **kennatt** » Sat May 10, 2008 8:01 am

when it does it again tap the top of the fuel bowl on the carb and listen for the pump suddenly ticking,if its been stood for some time could be that the needle in the float chamber it sticking and although letting fuel to the top of the carb not into the carb bowl.good idea to change the needle asembly anyway after a long lay up,can also stick open and flood the carb and rest of the engine bay,which isn't good

Post by **sidsmith** » Sat May 10, 2008 12:37 pm

well the saga is finally ( I hope ) over, the sound I heard from the engine as though there was something floating around was the result of the fan belt being too tight after I put the water pump in, as soon as i loosened it off to the required setting it was ok.
As far as not starting was concerned, I checked everything over again and I found the vacuum pipe to the carb' wasn't pushed right home, so as soon as I corrected it I fired it up and it started first time. So that's it, thanks for all your help, I can now go to the classic meeting on tues' night.
cheers "mungo "

Post by **bmcecosse** » Thu May 15, 2008 11:48 pm

Blocked up bypass connections would NOT cause overheating - later engines didn't have it anyway. If tight fan belt caused a noise - I would suspect a bearing on pump or generator is on it's last legs - or maybe the bottom pulley is disintegrating - they seem to crack around the rivets and eventually fall to bits. Best check it carefully before it stops you in the middle of nowhere!

Post by **sidsmith** » Fri May 16, 2008 10:24 am

hi, the fan belt was put on too tight and consequently the water pump made a funny noise but as soon as the fan belt was loosened the noise disappeared. the water pump i obtained from the mm centre at oldbury and was a new one so I shouldn't think it was the bearings

Post by **bmcecosse** » Fri May 16, 2008 2:08 pm

Hmm - well if it's new it should be fine - but the noise may have been generator bearings protesting. As long as the belt doesn't slip (squeal noise) it should be fine.