It’s that same old problem. ” As soon as my car gets hot, I turn the key and nothing happens. Let the car cool back down, and it starts perfect every time.” It’s irritating and frustrating because you don’t understand what needs fixed. You may have installed a new starter and the problem is still there ! The worst thing is, even a jump start doesn’t help. All you can do is sit there like a bump on a log and wait for the car to cool back down so you can go on with your day….Mechanics call the problem “Heat soak” or “Cold Start” . The driver of the car calls it ” A pain in the #%$! ” …. Here are some causes and solutions.


1. Solenoid head gasket .

final-cutstarter-solenoid-003  final-cutStarter-004

Much of the problem occurs when the copper in the solenoid coil becomes soaked with heat. Once the coil reaches a certain temperature, it will lose its ability to act as an electro magnet. If the solenoid coil isn’t strong enough to pull in the steel plunger when you turn your key, nothing happens. And that’s exactly what you get…nothing, no click, no crank, no sound at all.

For GM starters, you can order a metal gasket that fits between the base of the solenoid and the aluminum housing where the solenoid bolts on. This cuts down on the heat transfer from the block to the solenoid, much in the same way a head gasket cuts down the heat to the heads. They’re easy to install, and relatively inexpensive you just have to watch that the solenoid return spring is in its proper location.

2. Heat shield on solenoid.


From the factory, many vehicles are equipped with a heat shield over the solenoid to keep ambient heat from the solenoid coil. In some cases, if the starter has been changed by a previous owner, the heat shield may have been omitted for ease of installation. People experiencing this problem should analyze the starter to see if it has been replaced before, by some previous owner. If so, and exhaust systems are nearby, consult the dealership to see if the vehicle was equipped with a solenoid heat shield, and if one would be available.

3. Wrap starter.

Heat wraps are available at most auto parts stores.

4. Wrap exhaust.

This step should only be a consideration if your vehicle is equipped with headers. Some header manufacturers wrap the entire header with a special cloth looking tape. From a starter’s point of view, the best results for coolest temps around the starter can be achieved by wrapping the header only 2 or 3 feet where it’s near the starter. This disperses the heat to other areas, but has a better effect on the temperature nearest the starter.

5. Solenoid helper relay.  Solenoid is shown mounted on starter for demonstrative purposes.


If you built your own hot rod, and don’t have a solenoid relay that is activated by the key, then the solenoid relay activates the starter solenoid, you might as well plan on having problems. In other words, if your ignition switch is directly wired to the starter solenoid mounted on the starter, tear all that crap out, ’cause it will never be right. There are many sites that illustrate the wiring diagram and explain “how to” for a helper solenoid that will eliminate heat soak or cold start syndrome. All late model stock vehicles are equipped with a starter relay solenoid. You can purchase these at part stores or dealerships inexpensively.


(1)  To ignition switch.

(2)  #10 jumper wire.

(3)  Battery cable.  Note: There is no jumper bridge to the #2 terminal.

(4)  #10 wire to battery.

6. #10 wire to s terminal .

Diagnose the integrity of the wire that activates the starter solenoid. Remove the wire from the solenoid and pull it out of the harness for visual inspection wherever it is within 14″ of any exhaust system. If it feels hardened in any area, or dexterity and flex ability of the wire has been compromised, cut the wire as far back as you can and replace it with 1 size larger wire. Also, if the insulation appears discolored, you can consider this an indication that this operation needs to be performed. After this has been completed cover the new wire with corrugated black wiring harness material. The ridges in the plastic help keep everything cool, so you can stay cool when your mean machine starts right up.

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