Hi

I have a 2000 Monte Carlo SS. Recently I was driving down the street and began to get a strong gasoline odor, so I drove straight to my mechanic's garage. Turns out one of the elbow fittings at the end of one of the fuel lines was leaking quite a bit. Lucky for me the car didn't catch fire or worse.

Initially my mechanic tried to replace the elbow fitting in a hurry while I waited, but was having a bit of trouble getting the fuel line to slide over the end of the fitting, so being late in the day I left the car with him and he remembered he needed to use some kind of kit the next day to replace the elbow. In the process he did cut back the fuel line a few inches at his first attempt (before he used the kit), but there was plenty of length so as not to have to replace the whole fuel line.

Since that day I haven't smelled gas and have not seen any leaking on the ground at all. The strange part is, since he fixed it, my gas mileage has dropped! Why would that be? I figured since I'm not leaking fuel anymore I'd get at least the same average MPG, if not even better, but that's not the case. Based on the car's computer tracking of my gas usage and miles traveled, I went from getting around 19.5 - 20.0 average mpg to about 16.5 - 17.5 mpg.

In case you're wondering, I did reset the computer after the repair and after I filled the gas tank. I made sure to reset it to get an accurate reading because I had been previously losing so much gas. Much to my surprise I'm not even getting the same average mpg as I was before.

I'm not great with car repair, but even as an average Joe who doesn't do much of my own repair, this is baffling to me. Even my mechanic can't seem to come up with any reason why.

If anyone here has experienced this before, or may know what I can tell my mechanic to look for, would be greatly appreciated! Thanks!

Paul

 

This is a tricky one but I have 2 friends that have had similar experiences. The one had a garage do some tune up to the car and it got terrible gas mileage I think he had to replace the computer, on an 05 SS. The best way to check the mileage is to fill the car and drive for 50 to 100 miles and check it doing the math. You might check the fuel filter on the car and air filter.
Best mileage is achieved if the Car will show at 75 on the highway the Tach. will be below or near 2K. Similar to the photo. This was on a 2013 Impala and it is probably geared different.
Sorry I can't be of more help.

 

Thanks for the reply! Yeah this is strange allright, especially since before changing the fuel line fitting I had been averaging 19.5-20.0 mpg for a very long time without much variance on those figures. (according to the computer). My mechanic also suggested manually doing the math, so I'll try that to compare it to what the computer calculates it at. Pretty sure fuel and air filter are okay but will check. I'm just thinking,...if it is either the fuel or air filter, why would I notice the drop in mileage immediately after the fuel line fitting was changed, unless just coincidence.

There is one other thing I forgot to mention.....about once every week or so when I start it after it's been sitting for a little while I've gotten a long crank before turning over and when it finally does turn I get a very rough idle until I give it more gas pedal. Only thing is, is that I never know when it's going to happen, and only once in awhile. It does seem to happen when the weather is warmer. We're headed into winter here in the northeast now, but we did have a couple of 65-70 degree days last week and it did happen once or twice on those days. This has been going on for months intermittently.

It's never easy with these cars, is it? Thanks again for the advice, I'm hoping someone else has experienced this and found a cure.

 

You mentioned the rough idle and I have been having that issue with a 06 Pontiac Torrent I have I changed the plugs, filters etc. and it still did it then it kind of stopped when I got home awhile back. So I asked the wife what she did to stop the rough idle. She went to a different gas station and stopped using ethanol. It could have been a bad blend? who knows. You might try some Lucas Oil fuel additive for a few times that may help. After 100K it might need new plugs that is what the dealer said anyway. The fuel filter can get plugged any time with all the bad gas out there it might be something to watch. Let me know when you find the solution?
thanks hope it gets better.

 

I thought it was the gas to. Although I went to different locations, I stayed with the same brand, my car just seems to run better with Shell. I have also been using the Lucas fuel treatment every 2-3 fillups for a few months now, seems to help a little. I've also been filling the tank after only going about 100 miles to try to keep the condensation to a minimum. Where did you find gas with no ethanol? I thought all gas had ethanol in it, no?

 

Well I guess I'm about to get some kind of answer. This morning went to start the car and got very rough idle, check engine light continuously flashing, and kind of a burnt smell, (but not the strong rotten eggs smell you would get from a cat converter). A lot of what I researched points to a misfire from possibly needing a tune up or maybe bad fuel injector, among other things. Couple these symptoms with the recent work my mechanic did when he cut a few inches back on the fuel line and replaced a leaky fuel fitting, and this sounds like all the symptoms will end up all being related to one problem.

We'll see, it's at the mechanics now, had it towed as opposed to driving it there, which I thought was the safer bet. Hope it's nothing serious! Any thoughts anyone who has had similar problems like I'm getting now? Thanks