Classic/Antique Car Repair/cooling system


QUESTION: Greetings,
1984 Pininfarina spider 2000
Normal operating temp 190 degrees @65mph
Current operating temp 165-175 @65mph
When stopped in traffic temp rises to 195 cooling fan starts and temp drops to 165-175 will not come up to 190
Park vehicle overnight, next morning start let idle, temp rises to 190 at that point steam comes from the radiator about mid point,temp continues to rise cooling fan starts steam disappears temp drops to 165-175, temp rises again and things repeat. Thermostat function o.k. radiator cap 0.8 new.Heater stopped working. Please feel free to ask for any clarifications if necessary.

Thank you,


ANSWER: If the temperature will not come up to about 190 while driving it tells me that the thermostat is not working right and a new thermostat is in order, a 190 degree one. I hope that you are running a 50/50 mix of antifreeze/coolant in the system. Water boils at 212 degrees and a 50/50 mix of coolant and water will raise the boiling point of the mix to at least 245 degrees and this should take care of the steam. Now the radiator pressure cap is working well will also raise the boiling point of the coolant to over 300 degrees f. As far as the heater, check the level of the coolant as if it is low and the radiator pressure cap is not working right the heat will blow cold air.

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QUESTION: Thank you Brad, Another question, would it be o.k. to install a t-fitting at the heater hose to better flush the system, or will that possibly cause problems in the future,also where can I purchase that good luck you mention?

Thank you,


ANSWER: Prestone makes a "T" kit to install in the heater hose to flush the system with. It is a good idea. As for where to purchase good luck, I have no idea. I ran out of luck today and had to redo a head gasket job as I crimped the gasket installing the head. Stuff happens and when it does not I guess that is good luck. Oh I see you were not asking about purchasing good luck but a flushing "T", most any auto parts house.

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QUESTION: Hello again Brad,

The heater supply line gets hot to the fire wall,as it continues to the heater core after the firewall, the supply line is cold? Friday I will be installing the new thermostat,just wanted to get all the questions out of the way before I mess things up!  

Thank you,


Good Morning:
Sadly my reference library does not have much in the way of Italian cars. And I never worked on them very much. So I cannot pinpoint the exact trouble with the heater having hot in the inlet and cold on the outlet. However that said here is what I do know. First every fresh air heater system must have a way to control the temperature inside the car. That means either mixing the fresh air intake for the heater with cold outside air or there is a control valve somewhere in the heater coolant lines. These are usually in the intake heater hose or could be attached to the heater core itself. This control could be disconnected or not working. There are several control systems used on cars. The first is the electronic computer controlled system used on late model cars which would not be found on your car. The second is a cable connected to the temp control on your heater control. The last is a vacuum system again controlled by the heater temp selector and then a vacuum line to a vacuum diaphragm on the heater control valve. If the heater control valve is functioning then the problem is 99% for sure a plugged heater core.Hope this helps and good luck.

Classic/Antique Car Repair

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Brad Sears


All automotive including antique and collectible. However if the car has been modified I can only answer in general terms and maybe get you pointed in the right direction.


Automotive tech instructor. Syndicated auto columnist 1970's though the early 1990's. Syndicated auto radio talk show, Ask Brad About cars, CBS Radio 70's through 90's TV Show "Last Chance Garage" 1980's PBS-TV syndicated. Auto instructor for the following companies: Fram Autolyte Holly Carter AMF Ford Motor University Of Conn Blue Hills Technical School Sugar River Technical Center Grew up in a family garage in Needham Mass and turned wrenches from the age of 14.

Manchester Union Leader, Nashua Telegraph, Motor Service Magazine, Yankee Magazine, Popular Mechanics (Saturday Mechanic early 80's), Los Angeles Times, New York Times, and lots more.

More than I care to remember. Basically Franklin Technical Institute in Boston, Northeastern University, Fitchburg State Teachers College, Tufts University, and a lot of factory schools along the way.

Awards and Honors
Moto Award winner. And much more.

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