Q: Heard Popping Sounds After Key Removal

asked by on

Today I was doing a coolant pressure test. I know I was supposed to disconnect the battery beforehand but I've had issues with the terminals connecting properly in the past so I left it alone because I figured the vehicle was off and hadn't been driven in hours. I disconnected the two sensors attached to the air intake and removed the air cleaner assembly box so I could get a better view of my hoses. At some point I got in and turned the key (not to start the car) just to turn the lights on, but I immediately noticed my heater was on and blowing (the sensors and assembly were still disconnected at this time). I quickly turned the heater fan off and turned the key back to the off position and removed it from the ignition. At that point I heard 3-4 very quiet popping sounds coming from inside the dash behind the steering wheel. My question is, do you think the quiet popping sound was related to not bleeding the coolant system yet, an electrical short, or just air sounds?

My car has 130000 miles.
My car has an automatic transmission.

If your truck has automatic climate control, what you heard could have been the air diverter doors moving back to their default position. We used to joke about some cars sounding like there was a little guy inside the dashboard running around slamming doors when you turned off the car. If it isn’t that, I’m not sure what to tell you except that turning on the key while the sensors were disconnected is liable to give you a Check Engine Light the next time you start up the car. The controller performs a system check as soon as you turn it on and it will see the sensors that are disconnected as being defective and store a code. If you are nervous about this or the sounds in your dashboard you can contact YourMechanic. They can send a technician to your home or office to check out your noises and let you know what is going on.

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. Heard Popping Sounds After Key Removal

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 will not hold antifreeze smoke coming from the hood and tail pipe

You may have two different issues now that the engine is leaking coolant in the engine compartment from hitting the curb and also blowing smoke out of tail pipe that most likely is a head gasket from overheating the engine....

Q: high pitched squeal and the sound equivalent to stones rolling in a tin can (driver's side front wheel)

This sounds like a brake issue. The brake pads have a wear indicator that will make a squeal-type of noise when the pads have been worn down. The stone rolling noise could be debris in the wheel brake area. It...

Q: Codes P0016 and P000b

Hi there. The P0016 code is a camshaft/crankshaft correlation bank(1) issue. The P000b is camshaft position slow response bank(1) issue. These codes together are an indication that camshaft timing is out of sync with the crankshaft. This problem has been...

Related articles

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...
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...
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.