The gas gauge on my 850 has always acted up some, but lately I feel it has been acting up more.

When I start my car, sometimes the gauge shows that my tank is empty and my gas light is on, despite the fact I know I have plenty of gas. Then, like five minutes into the drive, the gas light will turn off and the needle will slowly move up and begin to register, and at this point show about how much gas I have. Then, through like 10 minutes of driving, my gauge will slowly drift down and back up, sometimes bottoming out on empty. This issue seems worse when my tank is getting low.

I suspect the float/mechanism in my tank is old and sticking and/or sinking when it shouldn't. I have tried jackrabbit starts, hard stops, and slalom maneuvers in an attempt to slosh gas around in the tank and "unstuck" the float, with limited success. Basically, my gas gauge has a mind of its own!

The one thing that does always seem to get it sorted out is by pumping gas into it. If I fill it to the top, it registers full. Even if I add 5 gallons when it is acting up, that typically will get it on track for a little while.

I was thinking I could try adding some sort of lubricant or solvent or fuel treatment to my next couple of tanks to see if that would sort out any sort of sticking issue, but I'm not exactly sure what the float mechanism even looks like, so I'm unsure how well that would work.

Help?

Thanks in advance!

1995Volvo850

 

Not much help, but here is a picture of it.

 

Well, I now know what it looks like! Thanks! I suspected it worked like a toilet float. I would guess the hinge part of it is at the top of the tank, and I would guess its stiff or something and possibly making the float get stuck, giving me the erratic readings.

Anybody think of something I could do to fix my issue? Something I could try adding to the gas?

 

You have a 95 right?

Run diagnostics on the cluster before you start replacing things.. That will confirm where your issue is...

If you dont know how.. Here Ya go ----->Volvo 850 instrument panel service repair manual

 

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