Q: Why does my E46 BMW M54 not start properly?
My BMW e46 always jumps on cold starts for a minute then clears changed coil pack and plugs and vacuum pipe to mass always code say cylinder 4 misfire could it be the injector
My car has 94000 miles.
My car has a manual transmission.
Recommended Services
| Ignition Coil Replacement | $132.12 - $587.62 | Get a Quote |
| Spark Plugs Replacement | $113.11 - $716.47 | Get a Quote |
| Fuel Injector Replacement | $400.56 - $3968.30 | Get a Quote |
| Fuel Pump Replacement | $145.32 - $1299.70 | Get a Quote |
| Engine is misfiring Inspection | $94.99 - $114.99 | Get a Quote |
Hello there, many faults will cause your 2003 BMW 320i to run poorly on cold start and have a cylinder 4 misfire. You have done great in replacing the coil packs, plugs, and vacuum pipe. Common faults would be a fuel injector, fuel pump, vacuum leak, wiring harness fault, or a ECU fault. A qualified technician, such as one from YourMechanic, will be able to diagnose your cylinder 4 misfire and perform any repairs required to resolve the 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
Car not driving straight.
If your wheel is not straight you could have a broken control arm or something else may be broken in the suspension. I would have the car checked out by a technician who can better determine the cause (https://www.yourmechanic.com/services/brakes-steering-and-suspension-inspection).
Car having trouble shifting gears
Hello! The most common cause of hard shifting is due to low or improper level of the transmission fluid. A qualified mechanic, such as one of our YourMechanic experts, will be able to diagnose your gear shifting problem (https://www.yourmechanic.com/services/transmission-fluid-service). The...
Code P0303 cylinder 3 misfire
The symptoms you describe along with the blinking Check Engine Light and P0303 trouble code definitely tell us that you have a misfire in cylinder number 3 (https://www.yourmechanic.com/article/p0303-obd-ii-trouble-code-cylinder-3-misfire-detected-by-spencer-clayton_2). Your engine uses a coil on plug system. This means each individual...
how do I change an external harmonic balancer?
You will have to remove the center bolt. Once the bolt is removed, then using a harmonic pulley puller and locking the puller to the three bolt holes and running the center bolt in until the pulley and harmonic pulley...
while driving at speed above 40mph i feel humming sound from real which die down on appling break.
Thanks for writing in about your Hyundai Santa Fe. From what you've described, it sounds like it may be from the rear wheel bearings (https://www.yourmechanic.com/services/wheel-bearings-replacement). When the rear brakes are applied, the brakes will quiet the noise down. Have a...
How do I know if the timing belt has been replaced?
You are correct in that the car fax may not necessarily always indicate every service performed as not all shops report the services they perform. Unfortunately, there is no definitive way to tell for sure whether or not the timing...
My dashboard lights,gauges,radio and power windows don't work. I can start my truck right up and drive.
Hello, thank you for writing in. Typically with the first symptoms you described I would direct you to check all of your fuses, focusing on the instrument cluster fuse. However considering the engine is showing signs of stress, you may...
Bubbles and pressure in the overflow tank
If the coolant level was low due to a leak, such leaks can be found during a leak diagnostic with simple pressure testing. If the cooling system doesn't maintain pressure, and no external leak is visible, coolant could be leaking...
I have a 2002 Toyota Camry and when I put it in reverse it cuts off.or when I start it it cuts off then I wait a few minutes then
Hello, thank you for writing in. The vehicle may be having one of several different issues. Typically this is attributed to an issue with an air sensor, either pertaining to the intake air or the exhaust. A sensor is usually...
Related articles
A Buyer's Guide to the 2012 BMW X3
If If you like high-end SUVs, the 2012 BMW X3 is definitely worth taking a look at. It’s a great mixture of luxury, utility and convenience. Key Features The Servotronic power steering on this SUV is excellent for giving you...
Symptoms of a Bad or Failing Fuel Pump
Common signs include a whining noise, hard starting, engine performance issues, and an inability to start the car.
Top Automotive News & Stories: July 27-August 3
Each week we compile the best announcements and developments from the world of cars. Here are the topics you can’t miss from July 27 to August 3. Most Stolen Cars List Released most stolen cars...
Browse other content
Maintenance
Services