Skip the auto shop - Our mechanics make house calls

Q: When I'm sitting in park my truck makes a loud bang sound

asked by on

Twice I have turned my vehicle on and as I'm sitting idle in park my truck has made a loud bang sound, no check engine light, no leaks, I'm not sure what the problem might be?

My car has 103000 miles.
My car has an automatic transmission.

A: Depending on the sound and the location of ...

Depending on the sound and the location of the sound, this may be related to a misfire/backfiring problem. Engine backfire is caused by an imbalance in the air/fuel ratio being supplied to the motor and will occur in one of two places. A backfire in the intake manifold is caused by a ratio that is too lean or not enough fuel. A backfire out of the exhaust system is caused by a ratio that is too rich or too much fuel. As there are many possibilities here, this may require the skill of a qualified mechanic such as one from YourMechanic to come to your location and diagnose your backfiring problem.

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: Engine revving, backfiring, cannot accelerate past 40 mph - 1990 Chevrolet G30

The poor performance and backfiring through the intake you mention are signs of a "lean" condition - not enough fuel for the amount of air flowing through the engine. You may have a vacuum leak or Idle Air Control valve...

Q: Engine misfiring.

A misfire can be caused by a lot of things, from a worn spark plug to an internal engine problem. The first step is to retrieve the diagnostic codes associated with the check engine light. These codes will provide a...

Q: Check Transmission Light coming on

Hi. The "Check Transmission" light indicates that a fault code is present in the transmission computer. To correct this, the fault codes need to be read in order to determine the issue. Fault corrections could be as simple as a...

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 to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...