Q: Engine hesitating in the first 20 minutes of driving when cold

asked by on

Hi. I have problem with my car when the weather is cold. It would start stumbling and hesitating in the first 20 minutes of driving. The dash would show check engine light flashing as well. After 10-20 minutes of running with these issues, the engine would gather speed and run fine. Also, it would occasionally stall at traffic lights. I went to the dealership but they couldn't fix the problem. They used a code reader and no error codes came. They had the fuel filters and fuel pump checked and couldn't find anything wrong. The issue is still there and I would like to know what could be wrong. The car has gone around 70,000 miles. Do you have any ideas? Thank you.

This could be caused by a cold state vacuum leak. Basically, this is a condition where a vacuum leak is present until the engine heats up and the induction parts expand and seal the leak. When the vacuum leak is present, you may be getting too much air, causing the engine to stumble. Because this happens during the warm up phase, the engine is running on preprogrammed values, so no fault codes are stored.

A smoke test on the induction system while the engine is cold might make it possible to locate the source of this leak. You may want to enlist the help of a mechanic, such as one from YourMechanic, who has the tools and expertise to diagnose the hesitation issue and find the best path of repair.

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 hesitating in the first 20 minutes of driving when cold

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 almost stalled, steering wheel locked up, all lights on dashboard came on, pushed gas pedal and nothing happened.

Hi there. When the engine is stalling and sputtering, this is an indication that the fuel system has lost pressure. Check the fuel pump relay and see if it is hot and if its clicking on when the key is...

Q: What do I do if the engine temperature gets too hot?

The engine temperature of your truck is important to keep an eye on. It is critical to safe vehicle operation and it is important to take the correct steps if overheating occurs. When the engine temperature gets too hot. ...

Q: Engine stutters then check light comes on at startup

Exhaust leaks can cause the check engine light to set. If you have an exhaust leak, it should be repaired because carbon monoxide is deadly. You can have the source of the leak identified, and repaired, by requesting an exhaust...

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...
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...