Alfetta Overheating

[joestram]

Hi All,

I took My Alfa Out For A Drive Today (5 Mins) In 32 Degree Weather And The Temp Guage Was Sitting On 110 Degrees And Wouldnt Even Go Down With the Heater On.

Does Anyone Else Get This With Their Cars In The Heat?

I last Drove The Car 2 Weeks Ago For Over 1 Hour And It Was Running So Nicely.

How Do I Fix It Because I Would Love To Drive Her In This Weather.

There Is Plenty Of Coolant And The Fan Seems To Come On Temporarily.

Thanks

Joe

[Nate Dog]

A few things,
Coolant flush, make sure the system doesn't have any blockades, check that the thermostat is actually tripping and the fan comes on, have the car running at idle with the bonnet up and look under the hood, should trip and turn the fan on. If its not that'll be an issue that needs sorting. Check the fan works properly, etc...

[GTVeloce]

Is the gauge accurate/faulty? Even if the fan wasn't working you should still be able to regulate the temp with some open road driving. I'd test the thermostat (remove and stick in a pot on the stove) and if that works then check the water pump by removing the belt and spinning it by hand. It should spin freely and easily.

Cheers

[MD]

Check polarity on fan connection. Is the fan working backwards?

Check water pump belt tension.

Is the radiator cap the correct pressure rating?

Is you ignition timing correct?

Is your mixture too lean?

[Davidm1600]

And even possibly check both under your oil filler cap and the dip stick to make certain you don't have a blown head gasket on the way.

In both instances when my Alfettas (GT and Sedan) had an overheating issue, it was the head gasket.

[MD]

If all that checks out, remove radiator, get tanks removed and the tubes cleaned. 99% of the time this is the core problem.
After reinstall, flush system with distilled water and ad a corrosion inhibitor to the water ( or a glycol based additive if you need anti freeze).

If that doesn't fix it, have a fire sale and claim the insurance...

[joestram]

Hey guys,

Thanks for all your comments.

It seems as though I was wrong about the fan. After some testing today in cooler weather, it seems as though the fan does not come on.

I will need to do some further investigation, but so far the fan spins freely and it seems as though it is connected properly.

There are no blown fuses so will check the alfetta service manual and try find a multimeter and see if it gets any power.

Thanks

Joe

[Neil Choi]

Joe,


Easy check is that on the RHS of radiator is the power and earth, as you know.


All you need to do is then jump the two connectors on fan thermo switch on the lower LHS of radiator.  The fan should come on.


Blown head gasket might be a good guess, you puttering around in cool temperatures being all fine, once hotter weather comes on, the ever so tiny leakage of combustion gas into the water jacket will heat up your coolant in no time and hence your 110 degree reading.  Also how old is the head gasket, probably original?

[joestram]

Hi Neil,

Thanks for the reply.

What do you mean by jump the two connectors?

Do I just unplug the temp sensor cables and the fan should come on?

I am going to repco tomorrow to replace the relay incase that is faulty.

There is no milkiness under the oil cap or on the dip stick plus there is no smoke when I drive (even if it is short).

The engine was rebuilt in 2007 or something so I am assuming it was done then but the previous owner was a little sketchy on details.

Thanks

Joe

[MD]

Joe,

Do I just unplug the temp sensor cables and the fan should come on?

What Neil is saying to you is this. Yes remove the connections to the thermoswitch that is located half way down the RHS of the radiator. However you need to join them together while the ignition is "on". This should start the fan operation and you should try to feel that the fan is pulling air into the engine bay. Once done, turn ignition off and replace the connector to the thermoswitch if it all works. If the fan does not run, well you need to diagnose why.

Hope I got that right for ya Neil..

[Neil Choi]

Joe,


Pull those two connectors off the thermoswitch and link them with a bit of wire (paperclip is fine) and the fan will run, assuming there is power to the fan on the RHS.  You can supply another power source to the RHS just to be sure in case the original wiring is not supplying any, use a multimeter to check for power on the RHS first.


You don't need to see milkiness in oil or oil in water, it could be the ever so tiny leakage and the combustion gas is acting as a cappucino machine on your coolant.  That said you can buy a test kit from auto stores to test for combustion gases, mainly carbon monooxide.


In my case, my car was running fine on all test runs but take it out on race day on the Friday practice and qualification, it heated up as I was using it at the extreme and that little leakage showed up badly.  Inspection of the head gasket where the metal seal on the cylinder showed a few tiny black radial lines less than 1mm thick. 

[Neil Choi]

i believe the thermoswitch is the LHS one.  I also believe we might has an orientation misinterpretation.


LHS of car as sitting in the car facing forward, does this clarify it?


Or on the side of the radiator near the exhaust and alternator.


Clear as mud?

[joestram]

Hi Neil & MD,

Thanks for the explanation.

I understand now. I just need to connect the purple and black wire that I removed from the thermoswitch with a cable.

If this works, does this mean the thermoswitch is faulty?

I am going to replace the relay as well as I have a strange suspicion that it might be faulty.

I will let you know how I go tomorrow - I will also get one of those radiator test kits as well.

Joe

[joestram]

Hi All,

I connected the thermoswitch wires together and the fan did not spin.

I then replaced the relay and the fan started to spin.

I am hoping that it was as simple as that and I didn't cause any problems with the head gasket.

I tried to get a head gasket tester from Repco and they didn't have any so I guess it will need to wait until I get my hands on one unless someone can recommend where I get them from.

Also, the relay I put in was a 5 pin 12v 30a. The one I took out didn't have an amp rating on it. There was only 12v 8c with 5 pins on it.

Will the 30a be too much?

Thanks

Joe

[colcol]

The 30 Amp relay should be fine, the 5 pin has 2 outputs for fans or driving lights, terminals number 87, the 4 pin relays, usually have 15 amps, with one output terminal, number 87, Colin.