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water system questions

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1540phil

New member
now the weather is improving we are going to bring the beasty out for some work.

before we put her away for the winter there were a few issues that we need to look at.

1) engine doesn't turn over.
done some investigation and I think the battery is duff so I'm gonna start with that purchase first.

2) intermitent reusal to fire up with engine turning over.
no needle movement so gonna replace the speed and crank sensors.

3) a new problem appeared late last year. overheating.
so my questions are based on the water system this time.

firstly which way does the water flow through the system?
i.e. does the water flow from the top radiator hose through the rad to the bottom hose, then into the water pump?
or is this the other way around?
could an air blockage in these engines cause overheating?
what is the best series of tests to diagnose an over heating issue.

The problem
driving at 30-40 mph there is no overheating problem at all.
stationary the temp needle just keeps rising alarmingly.
the fan kicks in at the required temp, but there is no difference.
There is no thermostat on top of the engine, is there more than one?

any help is greatly appreciated as I am still unfamiliar with this car.

Thanks
 
Phil
nice to see such an early car being looked after

There is a routine for checking the hall sensors - I would google it or try clarks garage before pulling them.

once you have it running, there are a number of comments i would make, but others will add more i am sure.

the water pump is at the front of the engine, directly below the dizzy cap. The water enters the head at the front almost in line with the bonnet pin on a large rubber hose about 50mm dia.

It is there that you bleed the system of air, 12mm AF nut, but is not a simple system to bleed, just awkward for some reason, google it for suggestions.

The head gaskets corrode, and if yours is aged the water path will be affected by this, and in turn the cooling performance.

If your fan is cutting in, the fan stat in the rad is working, and if it is working, the thermostat in the water pump is working.

I wonder how good the core of the rad is, or if its fins are blocked...?

Sorry I cannot be of much help

George
944t

 
George is all correct.

I would add that the thermostat is mounted just after the water pump at the top of the large hose going to the bottom of the rad.

Bleeding them is best done with the front N/S on a ramp and done several times! (they can be a real pain)

Also, I had an '83 car which had similar cooling "performance" to yours and this is the head gasket - the holes allow the coolant to shortcut the required route.


 
Does the coolant not enter through the water pump and exit at the top of the head by the bleed screw?
 
As ever, Clark's Garage has the detail, including a diagram of the coolant flow and details of how to drain / fill / bleed the system.
 
Does the coolant not enter through the water pump and exit at the top of the head by the bleed screw?
Click to expand...

Quite possible, check this point Phil, I always assumed the opposite flow direction.......

Thx Tony

George
944t
 
will do george.
I will firstly be removing the thermostat to check its working ok,
then I will fill up and bleed using the elevated front nearside wheel method.

I too initially thought the water went out the top of the radiator,then back in from the engine, via the pump into the bottom of the radiator.

However I also thought the thermostat was on top of the head near the bleed valve, where it is on most other engines.
But clearly not!
 
My thermostat was knackered and not opening until 100 degrees. New thermostat did the trick, also replaced the radiator too and seeing 80-85 on the temp gauge now :)
 
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