Alfa Romeo Forums banner

1 - 11 of 11 Posts

·
Registered
Joined
·
92 Posts
Discussion Starter #1
So many questions.
Does the cooling fan behind the radiator run all the time or is it controlled by temperature?
Does anyone have a good drawing/diagram showing the system and its components?
Has anyone had success with a draining, flushing, re-filling process? What coolant and mixture did you use?
What is the stock and or recommended thermostat temperature?

As always, your time knowledge and experience is appreciated. Hope you all are staying safe during the pandemic.
 

·
Administrator
Joined
·
17,057 Posts
And what color is it...?


Ok, engine driven fan obviously runs whenever the engine is running. If there is an electric fan ahead of the radiator that is switched on when the A/C is turned on. There is a small temp sensor on the right side of the fan shroud.
 

·
Registered
Joined
·
92 Posts
Discussion Starter #5
Dirty red.....
I don't believe that it has A/C (Air Conditioning) it is a convertible. It does have heat/cool slide selector. I'll have a look and post a photo or two.
I'm thinking it may be the thermostat gone bad, gummed up or not opening allowing the flow of water through the entire cooling circuit.
I will have a look for the fan in front of the radiator.

Thank you,
Mike
1986 Spider Graduate Convertible
 

·
Registered
Joined
·
92 Posts
Discussion Starter #7
Okay, so I took pout the thermostat and housing and placed it in a pan (wife not happy) boiled the water and observed that the thermostat does open. I did not measure or record temp, but it opened before the water came to a boil. Thinking about the water pump. How to prove that it is pumping water and not frozen, without removing it if possible.
Also wanting to drain, flush, and refill the system but would like some advice on diagnosing/troubleshooting the cooling system.

Thanks again for all your help...
 

·
Administrator
Joined
·
17,057 Posts
A neglected cooling system will likely lead to a clogged radiator. Draining and flushing with a garden hose might help but if truly clogged it probably needs professional help. Find Ye Olde Fashioned Radiator Repair Shoppe (typically on the wrong side of the tracks in a medium to large city) and bring the radiator there. They have the harsh chemicals that will get the inside really clean. If it is really bad they can take it apart and solder in a new core.

The block has a drain plug - inconveniently located behind the exhaust manifold. You might be able to see it or feel it but not both. While the radiator is out, flush the block using the garden hose. Open the valve to the heater core (push the console lever to 'hot') and flush that out, too.

1629475


When you re-install the radiator and refill the cooling system (any modern coolant is fine - it must be compatible with aluminum) find the two bleed screws. One is on the top of the water pump, the other on top of the intake plenum. Open the bleed screw on the water pump and slowly fill the radiator until coolant comes out there. Tighten that bleed screw and keep filling. Add coolant to the reservoir (make sure the small dia hose from under the radiator cap & reservoir is in good condition) and start up the engine. As it warms up, open the bleed screw on the top of the intake plenum until coolant comes out there (don't burn yourself!). Check the coolant level in the radiator after it cools down and keep the reservoir at the full mark. Once the radiator is full, excess coolant should freely flow back & forth to the reservoir. IF the level of coolant in the reservoir keeps dropping or rising there is a problem to be checked.

1629476
 

·
Registered
Joined
·
871 Posts
Agree with all the above, just one addendum. Best to use de-ionised water with the correct coolant for aluminium, means you'll create less / no more internal corrosion between the surfaces where aluminium and steel / cast iron come together.
 

·
Registered
Joined
·
92 Posts
Discussion Starter #10
That's awesome. Thank you very much. I will embark on that project soon. For this moment, it is running well and holding the temp of +/- 175*. I believe the t-stat was stuck closed not allowing the coolant to circulate. Many other projects for this car, but out is running and not overheating, so I can tackle the others as time and money permit.
 
1 - 11 of 11 Posts
Top