How to Repair an Overheating Head Gasket in a Vehicle

There are many causes of overheating in a car, but one you really want to avoid is the head gasket. If that’s blown, then the only way to repair it is to replace it. That’s a very complex job and one you shouldn’t attempt unless you’re a good, experienced mechanic. The gasket itself is cheap, but the labor and knowledge involved is extensive.

Step 1 - Preparation

Make sure that the engine is cool before you begin to work on it. Loosen and remove the negative cable from the battery. Raise the front end of the vehicle with a jack and place it on jack stands. This will allow you to slide under and loosen the bolts for the manifold from the engine block. When this has been done, you can lower the car from the jack stands.

Step 2 - Disassembly

Much of the work in replacing a head gasket in an overheating vehicle is simply getting to the head gasket. With the hood open, begin by taking out the air cleaner assembly, followed by the upper radiator hose and the thermostat housing that’s inside it at the engine block. Finish this section by removing the wires from the spark plugs. You’ll now be able to access the valve cover.

Step 3 - Valve Cover

Take off the valve cover and follow that by removing the rocker arms and the push rods. Be especially careful with these, as they’ll need to be in perfect condition to go back into the engine. At this point, you’ll be able to reach the head bolts.

Step 4 - Removing the Head Bolts

The head bolts need to be removed in a specific order. To know the correct way to do this, check in your service manual. It’s vital that you follow the instructions for this. Once they’ve been removed, you’re going to need to pry off the head, away from the old gasket. It might require a hammer to loosen the head. Lift it off and expose the old gasket.

Step 5 - Head Gasket

Peel off the old gasket and discard it. Before you can put on the new gasket, however, you need to clean both the block and the head to get rid of all the old gasket material that might be stuck there. Start by using a scraper to take off the residue and then finish with a solvent on the metal, allowing it to dry.

Put the new head gasket in place. Be certain it’s in the correct position and that the pins are all through the correct slots. Put the head back in place over the gasket and start to tighten the bolts. Again, this needs to be done in the proper order, and each needs to be at the right torque, so you’ll need to refer to your service manual and use a correctly adjusted torque wrench. Reassemble the engine in the reverse order to disassemble.