Skip the auto shop - Our mechanics make house calls

Q: Strange whirring noise coming from the engine

asked by on

We recently drove to North Carolina and back, approximately 1400 miles. Before the trip, I replaced the blower motor and resistor under the dash, because the fan would only work on setting 4, and the blower was sounding bad. Everything worked great for about 400 miles, besides the a/c blowing semi cool air. After driving for many hours and stopping for lunch, we continued our journey. Shortly after, mist started coming from the cents and our semi cool air now, had become warm. Not hot, just not cool. I took it as the Freon being low or empty, so we turned the a/c off for the rest of the entire trip. When we returned home, I purchased a bottle with a gauge to recharge the system. I did not use the entire can, but still managed to overfill it. By a little research, I found I could bleed it. I bled very little, and the a/c was working great. After about 3 hours of driving, the warm air returned and a fairly loud whirring sound started in the engine. Sound stops when car is off

My car has 100000 miles.
My car has an automatic transmission.

A: It sounds like you are getting water built ...

It sounds like you are getting water built up inside the evaporator housing and need to unplug the A/C drain or you will flood the evaporator, blower motor, and resistor with water and short the motor and resistor again. If you’d like a local expert to check this out, a certified technician from YourMechanic can come to your home or office to inspect the A/C system and whirring noise in order to determine what fixes should be done.

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

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 front drivers was told wheel bearing might be backwards only grinds when going straight not turning

This may be either dragging brake rotors or bad wheel bearings as either of these will cause this kind of grinding sound. I would recommend having an expert from YourMechanic come to your home to diagnose the grinding sound and...

Q: Stuttering at idle at regular intervals of about 7 seconds on a 1997 Honda Civic

Yes, it is typical on those Hondas. First, watch my video "How to Fix a Car that Idles Poorly." Take off the air intake, then duct the rubber part that goes to the intake on the top of the engine...

Q: Clutch and brake pedal feel strange

Hi, it sounds like you have a defective clutch master cylinder. I would inspect the clutch master cylinder as well as the slave cylinder. To replace the clutch master cylinder drain the brake fluid out the reservoir then disconnect the...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
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...