58 replies to this topic

[Keith Staley]

Daft questions but have you got the heater valve opened when running - can you feel the heater matrix inlet/outlet pipes getting hot? Also did you bleed the air out of the system after the rebuild - run the engine with the cap off? 

 

Apart from that, the only part of the system you haven't removed & visually checked is the water pump so I'd be looking at that.

[Chinna]

Hi Keith,

That is a very good question actually.
I was not sure.so I removed the hoses either side of the heater valve thingy and checked that the valve is open when I pull the lever on the dash. So, yes, I did check that.
The inlet hose was warm where it is directly in front of the rocker cover. But it wasn't particularly warm beyond that.

Yes I did bleed the system. I.e. leave rad open while pouring more water in.

I was a bit reluctant to take the water pump off. But I guess I have to now.

My radiator doesn't have a drain plug which is infinitely annoying !

Noticed that the heater inlet pipe is not warm. Will try a few things that have been suggested.

Edited by Chinna, 12 October 2015 - 07:11 AM.

[1984mini25]

Before you take the water pump off. I've had to in the past with mine while refilling the cooling system to get all the air locks out of the heater. Is to have the rad cap off, heater valve closed and using a small funnel pour more coolant through the inlet side heater hose, before reconnecting. Thus pushing any air locks through the heater and out though the rad.

[Chinna]

Before you take the water pump off. I've had to in the past with mine while refilling the cooling system to get all the air locks out of the heater. Is to have the rad cap off, heater valve closed and using a small funnel pour more coolant through the inlet side heater hose, before reconnecting. Thus pushing any air locks through the heater and out though the rad.

That's good advice. I'll try that tomorrow :)
But if u keep the heater valve closed, how will the air lock come out?
Thank you

Edited by Chinna, 12 October 2015 - 07:10 AM.

[Chinna]

Forgot to mention that I accidentally broke the vacuum advance pipe. So, the car wouldn't start. Someone rightly or wrongly suggested that I blank the pipes of at the dizzy and carb ends. Could this interfere with the timing and therefore causing the car to overheat ?

I read somewhere that I can replace this vacuum advance tube with a samco 3mm vacuum tube. I hope this is correct.

Edited by Chinna, 11 October 2015 - 09:50 PM.

[Dusky]

it wont change the advance enough for the car to overheat. Put it will drive less 'fluently'

[karlnz]

got the fan on the right way round?

[Chinna]

it wont change the advance enough for the car to overheat. Put it will drive less 'fluently'

Ok Thank you. I have ordered a meter of samco 3mm vacuum tubing

[Keith Staley]

1984mini25 gave you some good advice about using a funnel on the matrix inlet pipe. I did the same whilst both heater pipes were disconnected under the bonnet until the water ran clean. Before that I had removed the heater valve and removed the crud from both the valve and the water gallery in the head with a screwdriver and then refitted once clean. With the thermostat housing and water pump removed, I cleaned whatever crud I could find behind both (including the bypass hose inlet in the head) and poured water through the thermostat opening in the head until it poured out through the water pump opening in the block nice and clean. Then I flushed out the radiator from both ends until again the water ran clean. After that I was happy that all parts of the system had been flushed and there was definitely no blockages, so I could rebuild it all back up with a new water pump, thermostat & housing and new top and bottom hoses. I bled the system and it stopped boiling over but just to be sure, I drained the system and repeated another couple of times before finally topping up with anti-freeze. Job done.

 

You will need to follow a similar procedure to make absolutely sure there are no blockages and the water runs freely through the heater matrix, engine, radiator and all hoses. If you are convinced that you've done all of that and it still boils over, then it must be a faulty thermostat that is stopping the water travel around the system. You can test the thermostat by putting it in a pan of water on the stove and heating it up to watch it open at 82 degrees or whatever temperature stat you've got.  

[1984mini25]

1984mini25 gave you some good advice about using a funnel on the matrix inlet pipe...

 

 

It only because I've found by just filling the radiator alone you still end up with an air lock/no coolant in the heater. Hence why I also fill the heater via the heater hose at the heater tap end. But I'm thinking if filling the system, getting a warm heater, but its still overheating then the thermostat might have been removed to 'fix' the overheating issue, witch doing so rarely does.

[Blatherskite]

Hi Keith,

That is a very good question actually.
I was not sure.so I removed the hoses either side of the heater valve thingy and checked that the valve is open when I pull the lever on the dash. So, yes, I did check that.
The inlet hose was warm where it is directly in front of the rocker cover. But it wasn't particularly warm beyond that.

Yes I did bleed the system. I.e. leave rad open while pouring more water in.

I was a bit reluctant to take the water pump off. But I guess I have to now.

My radiator doesn't have a drain plug which is infinitely annoying !

Noticed that the heater inlet pipe is not warm. Will try a few things that have been suggested.

Had a problem with heater valve a lifetime ago; open valve, no hot, in the winter. Eventually took the valve off the head & found a rubbery plug in it that stopped the water flow. Don't know where the rubbery bit came from. Worth a check that open mechanism = open valve?

[Chinna]

Gentlemen ! Take a look at it for yourselves!
I'll replace the water pump and report back. But I can't thank you all enough for your help !

[1984mini25]

I said the thermostat had probably been removed to 'fix' a cooling/overheating issue. Just don't go fitting one of the horrid bellows type bypass hoes, a short section of 1/2" heater hose is what you need.

[Chinna]

I said the thermostat had probably been removed to 'fix' a cooling/overheating issue. Just don't go fitting one of the horrid bellows type bypass hoes, a short section of 1/2" heater hose is what you need.

Ha ha "fix" by a"mechanic" ;)

Yeah I am replacing all the hoses with a set of silicone hoses.
So the only bit that hasn't been renewed in the cooling system is the radiator.

[Chinna]

I was just wondering what that white stuff is. Is it a sign of oil mixing with water ?
But it us hard as concrete though. Any ideas gents