The last time I had seen my friend’s son he had asked me about a car problem. So when we met again I inquired how it worked out. His reply was that the “gasket” was bad. When I probed further I could see that there was no interest in revisiting this car repair encounter. The car was fixed and he had moved on.
Being told by your technician that the problem with your car is the gasket is like being told by your doctor that the reason you feel bad is that you have a fever. It’s an explanation but not much of one. So what are gaskets, what do they do, and where are they found in your car?
There are a lot of joined surfaces in your car. From the innards of your engine to the area surrounding the doors wherever two surfaces meet there’s likely to be a gasket. It doesn’t matter if it’s metal meeting metal or hard plastic contacting softer plastic, you just might need a gasket. But why you ask?
The answer is easy, because things leak. For example, your car’s thermostat is kept in the thermostat housing and is joined to the engine with nuts and bolts, since the thermostat is constantly dealing with coolant it would leak if it weren’t for the gasket placed between the housing and the engine. Since the gasket is made of softer material, it allows the nuts and bolts to be tightened sufficiently to prevent a leak. Without the gasket, the junction of the two metal surfaces would certainly leak coolant or the parts would crack as they were over-tightened.
Gaskets don’t just prevent engine fluids from leaking. They also prevent air, exhaust fumes, rain water, and noise from escaping. The exhaust gasket is a good one to consider because it has a dual purpose. The exhaust pipe configuration in your car consists of a number of pipes that contain devices to reduce pollution and noise. At the point each pipe joins there is usually a gasket. If these gaskets deteriorate or somehow fall out, your exhaust system would become loud and leak exhaust fumes and or pollution into the atmosphere or possibly into the cabin of the car.
Gaskets are made from a lot of materials. Some are cork. Others are hard paper or fiber. In the example of the car door, the gasket is usually rubber because of the need to repel both rain water and road noise. Gaskets are susceptible to being over-tightened at which point they sort of mushroom out of the surfaces that they are meant to work with. Good technicians know by feel just how far to tighten things to both prevent a leak and preserve the gasket.
The funny thing about the lowly gasket is that its failure can cause big problems and expense depending on which gasket has failed. A labor intensive job like replacing a bad head gasket can involve hours of time to replace a relatively cheap part. That’s why it doesn’t make any sense to accept “the gasket was bad” as an explanation for your car’s repair.