Skip the auto shop - Our mechanics make house calls

Q: The car has a very hard time with cold starts.

asked by on

When starting the car for the first time in the morning, it always has a really tough time getting going. The starter motor will rev rev rev really quickly for a few seconds before the engine will begin to stumble. It will stumble for a little while, with these little ignitions here and there but no full start of the engine. This only happens in the cold if after the car has been turned off overnight. Pressing on the accelerator while the starter is turning will remedy the problem somewhat.

I've replaced the battery already. I've also replaced the starter motor. I checked for vacuum leaks around the intake manifold and the vacuum lines. I've also checked fuel pressure, which came back normal. So far everything about the car seems normal. Thanks.

My car has 130000 miles.
My car has a manual transmission.

First make sure that all scheduled maintenance, particularly critical items such as spark plugs, is up to date. The purpose of that is to rule out the obvious, easy to deal with and already necessary items. If that does not resolve it, you’ll want to check things like the idle air control valve, any air induction sensors or controls such as a mass airflow sensor and global engine sensors, such as the engine coolant temperature sensor which lets the PCM know that the air fuel ratio has to be adjusted for a cold start.
The fact that the problem is mitigated when you open the throttle would suggest a problem with the air metering when cold such as a stuck idle air control valve or other throttle body fault. To resolve this in an organized way, the recommended diagnostic is hard start inspection. At the conclusion of that, the certified mechanic would let you know of the faulty component or system and thence estimate the repair cost for you. If the problem is simply a stick IAC valve, sometimes that can be freed up, that is cleaned, without the need to replace the component.

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: A6G A6GC plug replacement

Hello there, thank you for asking about your 1986 BMW 635CSi. According to the spark plug cross reference website, the A6GC is a direct replacement for the A6G. You should have no problems using that plug. If you want to...

Q: security system is disabling fuel, runs rough, sputters, kills, and hard to start.

Hi there. If your vehicle has a aftermarket car alarm, you can always remove it from the vehicle. If the alarm is factory, then you will not be able to remove it, but you can repair it. It seems as...

Q: Interior light won't turn off

If one of the lights inside the vehicle is not turning off, then there is likely a short in the wiring or switch for that light. As wiring problems can sometimes be hard to diagnose or detect, I would recommend...

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...
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...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...