Z31 Overheating

Here are some quick fixes if your car is overheating.

1. Is the radiator clear of debris?

Leaves, and road debris can clog your radiator. If this happens the air flow through the radiator will be reduced therefore reducing the cooling efficiency of the radiator. If you have a lot of Debris in the fins of your radiator take a hose and rinse the fins from the rear at a low pressure. High pressure water can damage the fins of the radiator.

2. Does your thermostat work?

A thermostat that is stuck shut will rapidly overheat your car regardless of speed or weather.

3. Does the car over heat at low speeds? IE Traffic?

This can be caused by two things. First your cooling fan clutch may be on its way out. Second and the easier of the two, Air trapped in the cooling system. To bleed the system of air, start the car cold with the coolant cap off. Bring the engine to operating temperature and then watch for air bubbles in the filler neck. Fill cooling system to the correct level till there is no more air bubbles coming out.

4. Overheating at high speeds only?

This is most likely a clogged cooling system or cooling passages. At higher engine speeds the water isn't in contact with the engine/radiator for long enough time to transfer enough heat to keep your engine cool.  Scale and minerals deposited by the water are pretty good insulators.  Give your cooling system a thorough flush and if that doesn't fix it you’ll probably need a new/cleaned radiator.

Sources used on this page:

• Written by: Thumper300zx