[ajkula66]

The patient in question here is our beloved '00 LX which has been in the family for eight years and has 152K on it. Not much of anything has been done apart from regular maintenance.

For the last ten days or so I've been noticing that I'm getting reduced MPG by quite a margin, and have been confronted by occasional gas odor. Apart from that, the car runs fine, no changes in behavior.

I can't see any leaks in the gas tank area, or engine compartment.

Where would you start?

Thanks in advance for any/all suggestions.

 

[OdyinNH]

The smell and MPG drop may not be related. Sniff around and locate where the smell is the strongest, my bet is near the gas cap. Could be the cap, a hose underneath (the rubber ones harden and crack on the ends) or the seal in the fill tube. There's a good post on sealing the fill tube on here somewhere, I sealed mine but still have a little smell now and then but no more CEL.

As for the MPG drop, could be many things. Dirty injectors, air filter, EGR port clogged, upper O2 sensor on the way out. None of these items is really expensive to clean or in the O2 sensors case replace and without a CEL you have no smoking gun. OEM parts are the best bet. Good luck and keep us posted.

 

[chrisarnt]

What about your tires ( pressure) ?
Extra stuff in the back?

 

[ajkula66]

Tires are Michelins Hydroedge with less than 5K on them...installed last year, well-balanced.

Nothing extra in the back...

 

[redmondjp]

Do you have a check engine light on? You can have an injector stick open, I've seen this happen with liquid gasoline running out the tailpipe (engine and exhaust system cold and just having been started), but this should throw a code and turn the light on so I doubt this is it.

Another possibility is a leak in your liquid fuel system somewhere between the in-tank pump and the engine (anywhere from right on top of the fuel tank to right on top of the engine). This would account for both of your symptoms. A shop with a lift will make it much easier to spot if the leak is underneath. You can check for this yourself but it's best to do when the engine is cold (a hot engine will quickly vaporize small leaks, and a hot exhaust will do the same as well as burn you when you are crawling around underneath).

A third possibility is a leak somewhere in your evaporative emissions system. The easiest way to find one of these leaks is to take the vehicle to a shop which has a "smoke machine" (actually it's a very fine oil mist) that is specifically designed for use in evaporative emission systems - it uses an inert gas instead of air, as you really don't want to be shoving air with oxygen into it into your fuel system.

The system is sealed off, the smoke is introduced into the system via a small tube at any convenient location, and then the smoke will find any leaks.

 

[ajkula66]

Wow! That's a ton of good advice in a single post...thank you!

It will be difficult to locate a shop with that type of gear in my one-horse-town, but I'll give it a shot...

The injector issue had crossed my mind, since I caught fire once due to a similar scenario, some two decades ago, with a Citroen DS 23IE, and at a gas station, no less...

My check engine light has been on for six years or so, my mechanic claims that it's due to an oxygen sensor that needs replacement...

To make one thing clear: the van runs great. It just dropped from a 24MPG average to something like 16MPG in a matter of two weeks or so...

Will keep this awesome forum posted on what happens next...if anyone has any more suggestions, by all means, chip in...

 

[Bill in Houston]

See if the wheels are particularly hot when you stop - maybe a couple of calipers/wheel cylinders sticking a little? Hope you can figure it out.

 

[OdyinNH]

My check engine light has been on for six years or so, my mechanic claims that it's due to an oxygen sensor that needs replacement...

Yikes, that may be your issue right there not to mention you could have more codes you don't know about. Have someone like Autozone read your codes. If it says O2 sensor then replace it already. How does your car ever pass inspection?

 

[ajkula66]

How does your car ever pass inspection?

There is NO emissions inspection in this neck of the woods. I wasn't kidding when I said I lived in a one-horse-town. Safety only - and for that they *will* fail your vehicle in a heartbeat. It has never happened to any of my cars, but I've seen it happen to other people for the smallest stuff imaginable.

As for the wheels/brakes, that thought had crossed my mind and I checked it quite thoroughly but it's all cool and well. This van will roll downhill for miles in N, she's always been good with that.

The odor has been absent for about three days now. And I know I wasn't imagining things...

Thank you all good people for your help, will keep you posted.

 

[OdyinNH]

The odor has been absent for about three days now. And I know I wasn't imagining things...

Gotta stress again that you need to check the codes. I was getting a p1456 & p1457 is also typical. Cracked hose, bad/loose cap, and there's some solenoid that can make the code, fuel smell from the 1st two items. Mine was dependent on the amount of fuel and position of the van. There is one Dunkin Donuts drive thru that would trip this code every time if I had half a tank of fuel.

 

[ajkula66]

Gotta stress again that you need to check the codes.

Oh I most certainly will, but for the next two weeks I'm working some pretty insane hours so that will have to wait, she'll just have to grin and bear it - the old gal - since most of the extra money that I'll make will end up in her anyway...:rollingeyes:

Thanks again for all the valuable info as well as for sharing your experiences.

 

[G8ROdy]

I hate it when these post never resolve. It's like a TV show that goes to commercial and never comes back.

 

[ajkula66]

Well, the issue really hasn't been resolved...hence the lack of *real* update of any kind....

Changed the sensors, and was OK for about 800 miles. Then the light came back on, and per my mechanic I need a new catalytic converter.

The smell has disappeared by itself.

I'm getting something like 18MPG which is a far cry from this van's normal behaviour, but my trans is on its way out as well. Slips between 2nd and 3rd are getting more and more common.

She's not being driven much these days, and I suspect that I will keep up with that practice until I'm able to put aside the $$$$ for a replacement trans.