Q: rough idle on start up everytime

asked by on August 10, 2016

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.

Car is hard to start Inspection $79.99 - $89.99 Get a Quote
Car is stalling Inspection $79.99 - $89.99 Get a Quote

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.

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

What others are asking

PCV valve and scheduled maintenance

Any time an engine has been neglected like this you should not hesitate to do any repairs to start to get the vehicle back on it's scheduled maintenance. You should have the PCV changed and change the oil and filter...

Car sucking air.

You are correct in that a vacuum leak could cause a rough idle condition. However, your issue has many potential causes. I suggest having a trained mechanic with the correct diagnostic equipment pinpoint your problem.

Car shuts off when stopped or going slow

There are many reasons why a vehicle may stall at a stop or at low RPM. I would recommend having your vehicle's stalling issue inspected at by a knowledgable technician, such as one from YourMechanic, to determine the exact nature...

How to get more horsepower without the check engine light and still still pass smog

Coming from a realistic point of view, I'd say that unless you were to pull your motor and completely rebuild it, from pan to fuel injection, you might want to consider NOT adding components for horsepower. With over 200,000 miles,...

Car starts, idles roughly, and dies.

Honda's are known to have distributor problems. I would have a technician, such as one from YourMechanic, check the codes. They usually give a cam sensor or tdc sensor code and if so you will need to replace the distributor....

Horn not working

If the fuse is good, the only other things it could be is the button (in the steering wheel) or the horn itself. I saw an issue like this before on the same vehicle you have, the wire to the...

Cranks but doesn't start and also I don't see the rpm move when I try to start, what should I do? - 2002 Nissan Altima

Hello - I suspect your crankshaft position sensorhas failed. This sensor provides the ignition system with timing information - when to fire each spark plug. This sensor is also the trigger for the tachometer, since it is counting engine revolutions...

I have a question, can I replace the ECM on this 2002 Dodge Intrepid engine with a used one?

Claimed by Kevin Gainer

I am looking to make a "sports" , "dub" car with alot of power.

Taking on a project such as this takes lots of time, even for the most experienced mechanic. You will be re-engineering your car and this will require you to learn a lot and make a lot of decisions. There is...

Related articles

How Long Does a Camshaft Position Sensor Last?
Most Most people get in their car and crank it without ever thinking about what it takes to make this process happen. A variety of different sensors and ignition parts will have to work in conjunction in order for a...
How Long Does an EGR Pressure Feedback Sensor Last?
In In today's world people are more aware of exhaust gases than ever before. With that said measures have been built into modern vehicles that are meant to cut down on the emissions released into the air. Built into your...
A Buyer’s Guide to the 2012 BMW Z4
BMW’s BMW’s entry in the hardtop roadster segment, the Z4 delivers the ideal combination of performance, looks, and standard comfort features. This two seater is not only classically stylish and heavy on extras that aren’t, well, extra, it’s also the...