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: While driving in town, heard thump and then squeaking

Hey there, thanks for writing in about your 1997 Mercedes Benz E300. Check to see if you see any tilting of the vehicle to one side. You may also notice an abnormal amount of bouncing when driving the car. These are all...

Q: Q: cooling system

If the check engine light is on and you have some preliminary indication that the "trouble code" implicates the engine cooling system, I would definitely consider that code as your first diagnostic clue. With regard to the temperature gauge, although...

Q: Tick in drivers side gets lower after warm up

In your initial question, I did not know that valve damage occurred as a consequence of a failed timing belt replacement. The 4 valves that the shop "claims" were damaged might merely represent what they "think" was the extent of...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
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...