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Porsche 993: How to Stop Leaking Gas

Fresh fuel smells great when you are pumping it into your car, but the same isn't true when you're driving around.

By Jeff White - March 26, 2015

This article applies to Porsche 993 (1993-1998).

A fuel smell can indicate a couple of things. You could be smelling gas because you're at a gas station, or you could be having some sort of gas leak. We all know how flammable gas can be, so it's best to inspect and fix the leak as soon as we smell it. Read on to learn how to troubleshoot a Porsche that seems to be leaking gas.

Before beginning to figure out where the leak might be coming from, you're going to want to have a good understanding of the components that make up the fuel system.

For stock 911 993s, this is the basic list of components in the fuel system:

  • Fuel tank
  • Fuel pump
  • Fuel filter
  • Fuel pressure regulator
  • Fuel pressure damper
  • Fuel injectors
  • Fuel lines

Step 1 – Check all fuel connections for tightness

After locating all the components that make up your fuel system, go over all the connections and check them to make sure they are not loose. Also, visually inspect around the connections and see if there are any wet spots or puddling fuel; this is a sure sign of a leak.

If you go over the connections and tighten them but they still leak, it is possible that a seal is bad, causing the leak, or that the fuel line has corroded and is causing the leak.

Figure 1. Porsche 993 fuel tank location.

Step 2 – Check the seal on the fuel level sensor

On the passenger side of the tank is where the fuel level sensor is located. There is an O-ring in between the sensor and the tank. If you only smell fuel when you fill your tank above 3/4, this is probably the culprit. You can order a new one and change it out pretty easily to solve the leaking problem.

Figure 2. Fuel level sensor O-ring.

Step 3 – Check the fuel filter and fuel pump for holes

There is high water content in some fuels, and the fuel filter and fuel pump have metal housings, so it is possible that it could have corroded from the inside out. This is especially common if you haven't changed your fuel filter along with the scheduled time interval that Porsche recommends.

Related Articles:

  • Porsche 993: How to Replace Fuel Filter - Rennlist.com
  • Porsche 993: How to Replace Fuel Pump - Rennlist.com
Figure 3. Porsche 993 fuel filter.

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