Gasoline odor may result from bad O-ring
By Doug McAllister
Q. I enjoy your column in the Daily Herald. You have helped me with a question before after I bought my 2000 Jaguar S-Type about three years ago. I had asked if I could mix 89 octane and 93 octane gas to get the 91 octane required for my car. You said it would not be a good idea, so I have been using the straight 91 octane gas. I get an average of 18 miles per gallon and am happy with the performance.
My new question also has to do with gas. My girlfriend always sits in the front passenger seat when we travel. She complains of a slight gas smell when I first start up and sometimes after making turns.
The gasoline odor lasts for varying amounts of time and goes away. I mentioned it to my mechanic when I had my oil changed recently. I have been using this mechanic for the last three years and am very happy with his work and trust him.
He took the car for a ride and did not smell the gas odor. He said if there were a problem with the fuel-delivery system, the "check engine" light would come on and a code would be left on the car's computer. The light has never come on.
My girlfriend says she still smells the gas. From my limited knowledge of the gas path from the tank to the fuel injectors, I know that even though the filler cap is on the passenger side of the car, the gas just goes into the tank and the gas line does not run along the passenger side of the car unless it does so after leaving the tank.
When I bring the car back for him to take another look, would it be appropriate to ask him to put the car up on the lift with the engine running and examine the fuel line from the tank to the injectors? Another thought would be for him to examine the fuel line from above with the engine running and the hood up.
I would appreciate any input that you have on this. Thank you.
- Sal
A. Hi, Sal. From the information given here, I suspect something seeping under the hood, like an O-ring at one of the fuel lines, or at a fuel injector.
It is probably not much and when it seeps on a hot engine, the liquid will disappear right away. Something like this would probably not turn on a "check engine" light.
I had a client complain of a random gas smell on his BMW and we looked and looked and could not find anything. Finally we found an O-ring on a fuel line buried back underneath the intake plenum. Once we replaced that, he never smelled it again.
Sometimes a small seep like this is very hard to find but you have to stay after it because it's not a good idea to drive around with a gas leak.
I am glad you are enjoying your Jaguar.
• Douglas Automotive is at 417 W. Main St., Barrington; 123 Virginia Road, Crystal Lake; and 416 Northwest Hwy., Fox River Grove. For information, visit douglasautomotive.com. Send questions to underthehood@dailyherald.com.