Skip the auto shop - Our mechanics make house calls

Q: vehicle is stalking and suddenly changing its RPM

asked by on

I washed my car engine with engine cleaner in car wash and later after drying, it started with new problem of stalking engine and smoke. Engine used to run smooth and clean before the car wash and after, it started making weird noise and not picking up the accurate speed while giving the accelerator. and at particular point of speed it suddenly reducing its speed and sudden changes in the RPM.. Don't exactly recognize what to do.... . It got 3 codes in check engine light stating:
1. multiple cylinder misfire; 2. Crankshaft reference 18x circuit malfunctioning; 3. Low EGR flow detected; and suggested to Replace ignition coil. . I was thinking to replace crankshaft positioning sensor. My problem can be solved by replacing it? Please suggest me.. what to do?

My car has 207000 miles.
My car has an automatic transmission.

Hi there. It sounds like there is water in a connector, such as the crankshaft position sensor. Before replacing this sensor, remove the connector and check for contamination. The contamination could be soapy water, oil, dirt, or any combination of water and something else. When this occurs, there could be an intermittent open or short occurring intermittently creating the erratic engine operation.Thoroughly clean with brake cleaner and dry the sensor and wire harness connector. Clear the codes and recheck the engine operation and codes. If the problem persists and the code returns, have a qualified technician perform an inspection to determine the specific cause of the concern and avoid replacing unnecessary parts. Your Mechanic has several available technicians that can assist you with a check engine light inspection.

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

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

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: Car stalling while driving - 2006 Pontiac Grand Prix

Hi there. The P0033 OBD-II error code is a generic code that typically indicates a problem with the Turbocharger or Supercharger Bypass Valve Control Circuit. In most cases, the reason the code is triggered is due to a vacuum...

Q: Headlights won't go off.

It sounds like you have a short in the wiring harness that goes to the headlight switch that is allowing the electricity to bypass the switch. I would recommend enlisting the assistance of a qualified technician who is experienced in...

Q: It runs for a hour or so, once it's parked it won't start back.

There is a GM problem report for the Pontiac G6 with this issue that identifies a loose, or corroded connector for the primary high-speed communication "bus" for the engine, transmission and other components (known as the CAN bus). Check with...

Related articles

P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.