Q: My system says there is water in the fuel

asked by on

Notice a little knocking when slowing down running rough and clears up if I punch it it don't knock will water cause knocking

My car has 300000 miles.
My car has an automatic transmission.

Hi. Yes, water in the fuel will cause knocking. I would advise doing a fuel system maintenance - drain the fuel system all the way to the tank, including the tank. This will get rid of any water and contaminated fuel.

I recommend replacing the fuel filters. If after servicing the fuel system, the knock is still there, most likely you have a sticking fuel injector and the injector will need to be replaced. If you would like to have this checked in person, a certified technician from YourMechanic can come to your location to diagnose the water in fuel and follow through with any needed repairs.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. My system says there is water in the fuel

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: Grinding noise from differential

It sound like your differential may be failing. There are many bearings and gears in the differential that may be damaged. A technician can use a stethoscope to pinpoint where the noise is coming from and determine if it is...

Q: Why after replacing the clutch does the clutch pedal have proper remission that only last a few weeks before the pedal tension is

You should check to see if clutch pedal free travel is less than 1/2 inch and then check the clutch reservoir to see if you lost fluid? If you are low on fluid then you may have a leak in...

Q: Need help diagnosing steering problem after hitting a curb.

It sounds as though you may have bent a tie rod. The tie rods are the links between the steering and the wheels, and they are normally pretty tough, but a good solid whack can bend them. Additionally, the new...

Related articles

How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
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...