Q: Engine shakes when heat is on

asked by on

I have a 2001 PT Cruiser. Engine shakes/vibrates loudly for like 2-3 seconds at a time on cold start only when I turn on the heat and let the car idle in park position. Does this for a while until car is "warmed up". Doesn't do it if I leave the heat off while letting it idle in park position on cold start. What can be the cause of this? Thanks.

My car has 106000 miles.
My car has an automatic transmission.

Hi There, This may potentially be a result of the change in heat in the coolant that results when turning on the heater while the car is still warming up. As you may know, when the car is first started when cold, the coolant temperature sensor reads the temperature of the coolant and relays this information to the ECU. Te ECU uses this information to make adjustments to the air/fuel ratio (adding more fuel) to the fuel supply as the engine requires more fuel to run when the engine is cold due to the difference in air density at colder temperatures. I would suggest having a professional from YourMechanic come to your location to take a look at your vehicle.

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. Engine shakes when heat is on

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: My car won't move when i press the gas pedal i have never had a problem before. I did notice a leak but i thought it was the oil from the transmission.

You should check for any codes that could be stored in the ECM (computer) as the check engine light is on. This will give you a starting place to check for the condition that you are having. Since the vehicle...

Q: Engine dies, runs rough and stalls

This may be a sign of a failing mass air flow sensor. The mass air flow sensor is a unit in the intake system that monitors air intake as it is mixed with fuel prior to being injected into the...

Q: Car waits a bit to start

In order for the starter to engage on this vehicle, the computer needs to disable the anti-theft system. Then the computer will signal the totally integrated power module (TIPM) to activate the starter relay, then the starter can begin to...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
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...
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...