C2 327 overheating

[Vetteman]

Hi Folks, I have recently acquired a fabulous 327 1965 C2

Only issue is overheating, its is just all over the place. Its runs hot then gets really hot, cools down a bit but always well above 180 bit never settles at one steady temperature.

Tried the obvious changing thermostat and sender, made no difference.

Any ideas welcome.

TIA

 

[Roscobbc]

Could be one or a number of the following things causing the problem.
Radiator partially internally blocked with crap caused by no coolant/antifreeze used at some earlier point. Engine block cooling galleries the same issue. Water pump vanes eroded (same reason). Radiator hoses collapsing and restricting flow (missing internal 'spring'). It the fan is a viscous coupled type....(failure of unit) Ignition timing too far retarded. Thermostat failure (seized).
Some higher powered engine options may struggle even with typical UK summer temperatures. Is this a recent thing over the last few weeks? (and coinciding with hot weather)

 

[Vetteman]

Thanks for your help. The previous owner had the same issue, replacing the thermostat and water pump and all piping.

The water pump is much hotter than the rest of the engine so I suspect clogging and blocking is the issue, perhaps rad and block.

Any recommendations on how to clear?

Also considering an aluminium rad, again any recommendations.

Thanks again

 

[Roscobbc]

Aluminium radiator - best choice is DeWitts, expensive, very expensive.......however buy once.......for remaining life of vehicle.
Suggest the use of proprietary rad cleaners initially ........... perhaps later someone to run industrial type chemical cleaners through the system. Problem here is that process may accelerate any 'weaknesses' with internally corroded engine block core/freeze plugs........some which may not be accessable with the engine in place..........leading to engine disassembly and need for professional 'hot tanking'.
I've been through all this with my '68 big block car. Being the first year C3 cooling in hot weather was at best marginal. First thing replaced was water pump. Sourced a high performance replacement. OEM impeller was steel (aftermarket ones are plastic/nylon perhaps). Years of insufficient anti-freeze and associated water cavitation and corrosion had partly 'worn' off the vanes on the impeller, reducing its efficiency. The other issue with many C3's (perhaps C2's as well?) is perhaps previous owners removing factory rubber seals and fillets surrounding the radiator and fan. Best establish what your car should have and replace if missing. Best logic is to aim for ALL cooling air passing through the front grille should ideally pass through the radiator (and only the radiator) - If a fan shroud was an OEM fitment......again make sure it is in good order and effectively sealed to front bodywork. If I recall Stewart water pumps are well reccomended by USA enthusiasts.

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