Cooling issues

[MattNoVAT]

Now that my car is more or less legal I still need to attend to its lack of cooling :-(

Water pump was replaced about 200 miles ago.

I have checked the timing and its bang on 10 degrees BTDC.

It ticks over at 900 - 1000 rpm very happily, but when giving it some gas it does hesitate and splutter.  Main radiator fan cuts in as normal, but all that seems to do is slow down the rising temperature until it hits the max and I shut off the engine.  Carb jets have been removed blown through and refitted.

I have jumped in and switched on the heater & fan and it blows extremely hot air at first then slowly it the temp of the air coming out the vents drops to "luke warm"  shut it off and leave it a couple of minutes and then switch it on again and very hot air is being expelled again. This makes me think that coolant flow is restricted within the matrix itself.

I've changed the thermostat and checked the replacement for operation before fitting. ( I get the same issue )

If I take the expansion tank cap off I can see water being returned back to the expansion tank. (so water is flowing round the system)

Radiator itself is v. hot and the tickover is not affected by the rising water temp. (Again, Thermostat is working and water is flowing around the system)

So, knowing that I had a few tickover issues a few months ago, I swapped carbs and discovered the original carbs thermostat housing was blocked, it was full of crud, l cleared it out but thats made me suspicious.

Today, when I swapped the main thermostat the old thermostat came out and had the same crud encrusted all round the outside of one of the connections (the large one that joins metal pipe section by 4" rubber hose).

This makes me think that possibly some of the channels in the main rad and also the heater matrix are blocked and restricting the flow of water through them, thus causing this slow rising of water temp as the flow efficiency has dropped.

And yes I have coolant in there!

Would appreciate a sanity check    

[thecolonel]

What colour was the crud (it makes a difference)

white'ish/yellow with blue/grey - aluminium corrosion
red'ish/brown - block corrosion

give it a good flush with some descaler (not too strong)
I suspect its either been run without antifreeze or plain water has been left in it

Geoff

[hutch6610]

How old is your radiator if i may ask?
May be worth having it re-cored by somebody like Serk Intertruck - had several done for about £110.00 and one upgraded by 40% for £130.00, no idea how much they charge now.
 
The corrosion on the outside suggests the hose is either not sealing or more likely the thermostat housing has become porous,

white'ish/yellow with blue/grey

As thecolonel suggests.

Again its likely you have sludge in the system and its blocking the free flow of the coolant in the rad - again as thecolonel suggests.

Having antifreeze in the system is one thing but having the correct concentration is quite another.
Antifreeze should also be changed every 24000 miles or every other year - don't use that horrible extended life red stuff, it leaches out of every pore on the car, some thing that does not happen with the standard stuff.

Do as thecolonel suggests and use a "flush" but on draining the system down flush out the radiator, the block from the 13mm plug under the exhaust manifold, expansion tank (you may want to wash this out to see the coolant level better) and heater hoses with a hose pipe - you want some pressure to blow the sludge out.

Flush in both directions  - the radiator and the heater hoses until all (or as much) of the brown/red stuff is gone.
You can refill with plain water for a short period - like a day - as you test the system out and then refill with coolant if you are satisfied with its operation.

To be honest antifreeze these days is not as good as it used to be as its kinder to the environment so make sure you have at least a 50/50 mix.
Better still get the the best antifreeze i have ever used - Paraflu from Fiat - dear i know but well worth it.

[MattNoVAT]

The radiator is at least 19 years old (thats how long I've had the car)

There is no sludge mixed in with the current coolant, when it is drained from the bottom of the rad it comes out like normal.

The crud that was in the carb thermostat was whitish blue, almost crystal like. So ally corrosion.

Its definately not block corrosion, of that I'm certain - plus the heater matrix spitting out very hot air and then dropping to luke warm makes me think that water flow is restricted due to ally corrosion throughout the cooling system.  Carb = ally (well a type of ally), thermostat = ally both suffering same build up.  So not a huge leap to think that rad and heater matrix have similar issues.

I flushed the system out already with descaler as part of the engine service.

While the car was in between welding and painting (about 9 months) a couple of years ago it had just plain water left in. That wasn't part of my plan, just the painter I used took ages to get on with the job and the whole thing dragged on.

Was gonna buy a Fluke infrared temp gauge to check the rads - but then I thought may as well have rads recored and swap them out and then if I need a temp gauge I'll get one if the issue still persists.  

[MattNoVAT]

Pulled the radiator out today, low and behold I can see at least three channels either blocked or partially blocked at the entrance/exit. Whats going on in the centre of those channels is anyones guess but methinks that there are plenty of blockages.  So i strongly suspect that this rad is toast and needs a recore.

I think its going to be the same issue with the heater matrix - looks like I've found both thanks to the forum. 

[MattNoVAT]

Pretty much the final update on this cooling matter.  I had my rad re-cored (£126.50 Feltham Radiators Ltd) came back looking lovely and before refitting I ran the hose into the flow/return of the heater matrix plus ran it through the block also just to see if any crud came out.  None out the block but a bit out the heater matrix.  So after that I refit everything and fired her up.  Then washed my daily driver while the Beta ticked over for 20 minutes. 

The Beta didn't miss a beat, cooling fan cuts in and out once the needle hits a touch over the halfway mark, plus the heater now fires out hot air all the time the fan is on and the bypass valve allows water through.  So all in all very happy now.

Might give Gordon Clown some money tomorrow and put a tax disc in her, so I can take her out on the road for some gentle running about to make sure all is well.

Then a hand wash and polish after I've drained some water out and dropped in some coolant

[hutch6610]

Cores block up over the years and can be a pig to clean out.
£126.00 is a good price by the way ............. and its surprising how it transforms the cooling of a engine.