Skip the auto shop - Our mechanics make house calls

Q: rough idle on start up everytime

asked by on

2003 BMW 318i 2.0. Car would take 3-4 tries to start up and then immediately stall if i didn't keep the revs consistent and between 1 and 2.5k. There would be loss in power while driving.

Parts changed to try and cure (btw no EML light and nothing on diagnostics):

  • EXH and INLT camshaft sensors
  • EXH and INLT solenoids
  • Timing chain tensioner (old one was 5mm shorter)
  • Full service

Timing chain was inspected with rocker cover off - was fine Car has only covered a genuine 58k miles

Rocker cover gasket was replaced about a year and a half ago due to smoke coming out of where the EXH manifold but this problem is still present whenever the car starts up.

All parts are from BMW dealer so this problem has cost me a lot so far.

So after these parts replaced. The car starts up first time but again have to keep revs over 1k otherwise it will stall. After keeping revs consistent and letting the car warm up for 10 minutes. The idling levels normally and then it drives fine with no fault.

My car has 58020 miles.
My car has an automatic transmission.

A: You could have several things contributing ...

You could have several things contributing to the hard start. Dirty or faulty throttle valve, idle air control valve, bad temperature sensor, and more. I suggest having a certified technician, like one from YourMechanic, perform a few tests to be able to diagnose the exact cause of your stalling issue.

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・Save up to 30%

Get a quote

What others are asking

Q: Changed DPF and still getting warning lights. Can't work as taxi driver, please help (Lexus 220D)

Hello. If the trouble codes are indicating that the dpfe is blocked, then there may be an obstruction in the system, or perhaps an electrical issue. The dpfe sensor functions using vacuum and exhaust gases. If there is an obstruction...

Q: Car sputtered and stalled after sitting

After that amount of time, the first thing I would check is the fuel quality. Water could have condensed in the tank. The fuel itself could have separated. Most fuel now has 10% ethanol. Gas and ethanal separate over time....

Q: Crankshaft sensor going out

That is a pretty common failure on the 4.0 engine. Random stalling, long crank, rough idle, or the engine failing to start are all symptoms. Usually a code is stored, but this is not always the case. If you would...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
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...