Hey guys, I did a search on the forum, and found a couple threads similar to my problem, but I could use a little advice about how to approach the problem.

I've got a 2012 G37x, had it for just over 3 years since it was new. Recently (last several months), the gas gauge readings have been changing from the way it used to.

Now: When the gas gauge is at 1/4 tank, it takes about 18.5 to 18.9 gallons to fill (meaning only about 1 to 1.5 gallons left). If I fill at the 1/2 mark, it takes about 14.5 gallons (or about 5.5 gallons left).

Previously: At 1/4 on the gauge, it would take 15.7 or so gallons (so a little over 4 gallons left), and the distance to empty would be appropriate. It used to be that if I ran got low enough to get the yellow warning dashboard light (did it cautiously in town a couple times just to know), it took 17 to 18 gallons to fill it (meaning 2 or 3 gallons left), and the gauge was heading down to E.

But now that's all changed. The car thinks I've got 1/4 tank left, and 60-80 miles to empty, and I fill up and it takes over 18 gallons to fill up, which used to be almost impossible to do. I use several different gas stations--same result. I don't squeeze the pump to try to get a little more in after the pump stops on its own. After fill up, the gas gauge goes just barely above the F, same as always.

I do notice that on the way down, driving through a tank, the gauge spends a lot longer around 1/2 than it used to, and on a couple occasions, I've seen it go down to 1/2, and then GO BACK UP to between 3/4 and 1/2 before going back down.

I had the car in for an oil change at the dealer, so I showed the service manager some photos I had taken of the gauge (showing that it wasn't close to E) and how many gallons it took for a fill. All I got was "Scanned for codes, no DTC's found in system all software current, could not duplicate concern within specifications." He told me there are no error codes, so there's no problem, and no technical service bulletins about it.

I really don't like running down to 1-2 gallons left in the tank. On the other hand, it doesn't seem right that I should have to fill up when the gas gauge reads 1/2 full. Thanks for any help.
What do I tell the service manager to look for?

I really don't like running down to 1-2 gallons left in the tank. On the other hand, it doesn't seem right that I should have to fill up when the gas gauge reads 1/2 full. Thanks for any help.

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Bring it to the dealer when the gauge is at the 1/4 mark and drive to the nearest gas station with the service manager. Take photos of the gauge and the gas pump.

Good luck

Telcoman

telcoman wrote:^^^^^^^^^^^^^^^^^^^^^
Bring it to the dealer when the gauge is at the 1/4 mark and drive to the nearest gas station with the service manager. Take photos of the gauge and the gas pump.

Good luck

Telcoman

Thanks for the reply. I went in with photos of the gauge at fill ups, showing that it was only at 1/4, but it took almost 19 gallons (and I've got the receipts from the pumps).

He says there isn't a problem unless there's an error code. When I said that I don't like being that close to empty, he said that we shouldn't let the gauge get down to 1/4 tank anyway, because it's not good to let the tank get that low. In other words, if I get him to go to the station, with me, we put in 18.8 gallons, he will probably say to me something like "So you just need to fill up before this" rather than admitting that it's a problem.

So he doesn't really want to look for a problem. I get the feeling I need to tell him "I've heard the problem could be the [fuel sending sensor(s), instrument cluster, ??? sensor, ??? wire], so how do we check this?" If I don't point him in the right direction, he will just send me away. Again.


RANT: Just like the problem I had with the left front wheel bearing, and just like the problem I'm having with the outdoor temp gauge reading incorrectly (same car, same response from dealer). Just like other problems I've had with numerous other cars when I knew something was wrong, but the dealer stands there and tells me I'm wrong. /END RANT

Anyway, what I need is info to tell him HOW TO DO HIS JOB, cause he won't.

Or do I call a different dealer (farther away), explain the problem over the phone, and see if they'll take it seriously?

There's lots of stuff that doesn't generate a code when it malfunctions. Since you have only had the car three years, this should be a warranty repair that the service manager doesn't want to deal with. He might be lazy or responding to pressure from a cheapskate owner. Can you try another dealer? It looks like there are two near Saint Louis and one in Kansas City. A Nissan dealer is another option.

I would contact Infiniti customer service and complain. There is a problem and it should be fixed....all of them. If you have a different Infiniti dealership somewhere near then I would go there.

Now, he does have a good point about filling up the tank earlier. The in-take fuel pumps use the gas itself to cool them. If you continually run the tank low the lifespan of the pump will be less. Granted, that mark is usually at 1/4 tank...which in yours is even less.

audtatious wrote:I would contact Infiniti customer service and complain. There is a problem and it should be fixed....all of them. If you have a different Infiniti dealership somewhere near then I would go there.

Now, he does have a good point about filling up the tank earlier. The in-take fuel pumps use the gas itself to cool them. If you continually run the tank low the lifespan of the pump will be less. Granted, that mark is usually at 1/4 tank...which in yours is even less.

My usual pattern has been to fill up at around the 1/4 mark or a little before, and the amount it took to fill meant that usually there was about 4-6 gallons left. So I hope that was enough.

Follow-up:
TLDR version: Internal failure of fuel pump housing and faulty fuel sender unit. Replaced. Problem solved.

Side note: I happened to mention this to a Nissan service manager I know (before the repairs). He immediately said it was a bad sender, and that Nissan had recalls on some models for it.

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Long version: I called the dealer again. They moved the problem up the chain (in Infiniti) and arranged to have some of the likely culprit parts on hand before they did anything, since they weren’t sure what was causing this. They’d get into the tank, take things apart and see what they’d find.

In the meantime, I shot a bunch more photos of my dashboard over the course of one tank of gas. Before, I had only shot photos of the gauge at fill-up (and the gallons needed to fill when the gauge was 1/2, 1/4, or whatever). This time, I shot photos during one tank of gas, showing it go down to 3/4, then back up above 3/4, down to 1/2, back up toward 3/4 (all showing the odometer readings), etc. etc. When I brought these in with my car the next time, they impressed one of the service managers more than my earlier photos had.

When they had the parts, I brought the car in with the gauge around 1/4, and showing about 75 miles to empty. (They told me later it had about 2 gallons left.) They found a faulty fuel sender (left side) and an internal failure of the fuel pump housing (a crack, I think they said). They replaced them, put it all back together, and problem is solved. Just fueled up today a touch above 1/4, and it took 14.0 gallons.

Yeah, just sad you had to go through that. I've had the "no fault found" excuse before but once sometimes when press them they will relent. In your case I hope they apologized.