Skip the auto shop - Our mechanics make house calls

Q: After fill-up, gauge went to top, then dropped to middle and stuck there

asked by on

The last time I filled up my Mazda, the gauge went all the way to top about 15 minutes after fill-up and then after driving about an hour, it dropped to middle and stuck there. How do I fix this?

The fuel sending unit inside the fuel tank uses a variable resistor unit to control the fuel gauge. If the sending unit is faulty then it could fail in any position, causing the gauge to not work correctly. A true test is to remove the sender and check the resistance of the sender while moving the float up and down. If it does not match the specification, then it should be replaced.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  • Home
  • Questions
  • After fill-up, gauge went to top, then dropped to middle and stuck there

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Motor smokes

Hi there. If the engine is smoking in the engine compartment area, you probably have a leak. When engine oil leaks out due to a bad gasket, it hits a hot engine part causing the smoke. This causes the oil...

Q: Motor makes window only go up slightly.

The problem is likely a faulty regulator or a window module that needs to be reprogrammed. BMW vehicles have an onboard computer (module) that must be programmed to know the correct window position for proper operation. A trained technician, such...

Q: Shifting issues, grinding noise. 2013 Scion FR-S

Hello. One option would be to adjust your clutch pedal or have it adjusted by a professional. It is also possible that there is a problem with the clutch slave cylinder. When this part is faulty it will cause a...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...