2010 fortwo Fuel guage at 1/2 when full

[Edwin52 1]

Suddenly guage is reading 1/2 when full. Where would I  find the info to probe the sender unit? OR is this a remove tank and replace sender job?

[Huronlad 178]

What brand and octane level of fuel do you use?

[jwight 102]

55 minutes ago, Edwin52 said:

Suddenly gauge is reading 1/2 when full. Where would I  find the info to probe the sender unit? OR is this a remove tank and replace sender job?

Yes, you have to remove the tank to replace the sending unit.

[Edwin52 1]

1 hour ago, Huronlad said:

What brand and octane level of fuel do you use?

The car has only ever had premium from Ultramar or Costco or Esso and synthetic 5W30 for its entire 119,000 life so far. The guage showed full 2 days ago. I had reset the trip odometer, I actually went to fuel up but it would only take a buck, that's when I realized something was odd.

[Nigel 191]

Here is an article I found on line that may be your problem.  You may have to read some additive bottles to find the right stuff up here I don’t know.  When I was with the CAA many years ago this was a very common problem with GM cars and Shell fuel around the late nineties.   I’m sure that is why Huronlad was asking you about the brand of fuel.  

 

Nigel

 

https://www.chicagotribune.com/news/ct-xpm-2006-06-25-0606250220-story.html

[jwight 102]

This is not a widespread problem in the world of smart cars (although the early 453s did have an issue due to the tank design).  My guess is the sending unit is/has failing/failed.

[Nigel 191]

I agree but I would certainly be willing to try some additive first.  A few guys have had issues on the diesels as well and an additive worked for them.  I’ve driven a couple of million miles over my lifetime and it is not an issue I’ve ever had.

 

Nigel

[Edwin52 1]

9 hours ago, Nigel said:

Here is an article I found on line that may be your problem.  You may have to read some additive bottles to find the right stuff up here I don’t know.  When I was with the CAA many years ago this was a very common problem with GM cars and Shell fuel around the late nineties.   I’m sure that is why Huronlad was asking you about the brand of fuel.  

 

Nigel

 

https://www.chicagotribune.com/news/ct-xpm-2006-06-25-0606250220-story.html

Thanks That's interesting, I just remembered adding for the first time, a fuel additive, Lucas upper cylinder lube. I have been using it in my Honda CX650 mc for years. Hope it isn't the cause !

[Willys 527]

2 hours ago, Edwin52 said:

Thanks That's interesting, I just remembered adding for the first time, a fuel additive, Lucas upper cylinder lube. I have been using it in my Honda CX650 mc for years. Hope it isn't the cause !

You have a CX650....I used to have a CX500. Damn this world is getting smaller and smaller with people having similar interests and hobbies.  lol   I still have a completely rebuilt CX500 engine I have now installed on a garden tractor to throw snow....well that was the idea any way...I have since lost interest.   You do not hear many people say they own a CX...that is the older ones...

[Leadwing 484]

5 hours ago, Edwin52 said:

remembered adding for the first time, a fuel additive, Lucas upper cylinder lube..........  Hope it isn't the cause !

 

At 119,000kms, you shouldn't be needing any upper cylinder lube additives.  The engine in its original state should supply sufficient lubrication on its own.  Personally, I would try a few tanks of pure gas ( no additives ) and see if that solves the problem.  It's less expensive to do that than to boldly dive into a sensor issue.  Of course, if that fails,  replacement might be your only alternative.

 

Good luck.

[Edwin52 1]

3 hours ago, Willys said:

You have a CX650....I used to have a CX500. Damn this world is getting smaller and smaller with people having similar interests and hobbies.  lol   I still have a completely rebuilt CX500 engine I have now installed on a garden tractor to throw snow....well that was the idea any way...I have since lost interest.   You do not hear many people say they own a CX...that is the older ones...

Yes, I tried to get to Victoria, BC summer of 2019 but only made it to Montana, had to head back home, terrible aching leg. Found out had to have my hip replaced. Done July 2020. No riding this year! The bike has 61,000 kms, Hope to try trip again next year.... Who knows what the world will be like then !!! ???

[Willys 527]

8 hours ago, Edwin52 said:

Yes, I tried to get to Victoria, BC summer of 2019 but only made it to Montana, had to head back home, terrible aching leg. Found out had to have my hip replaced. Done July 2020. No riding this year! The bike has 61,000 kms, Hope to try trip again next year.... Who knows what the world will be like then !!! ???

I also have ridden all over our country on a bike, not the CX but a KLR650 heavily modified for distance riding and comfort. I couldn't ride my CX down to Toronto after creating a bobber styled machine, back and neck and hips just would allow it. Shame as the bike was sweet! Oh well....I have since sold all bikes and swapped them out for long distance for a Smart car...lol. dry, warm, comfort and easily packed...lol.  And no two man tenting..I figure without the passenger seat you may just be able to sleep inside....I did love it all, but we all get older and more crippled up as that happens.
Sorry to Hi-Jack....now back to the regularly scheduled topic....I agree with the mechanic's in a can for some instances also and this is perhaps one of them for sure. As suggested far easier, cheaper and it does work for some, to dig far deeper into the issue.
Good luck....on all accounts.