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Sudden rough idle loss of power...because of shifting?

15K views 17 replies 7 participants last post by  jakethesteak 
#1 ·
Hello all. I was literally a stoplight away from work when this happened.
I was behind a Kia Soul and I was just looking at the rear end of it when the light went green. Realizing I was in neutral I quickly shifted into 1st but it felt weird (kind of like the reverse gear) so I pulled out and put it in 1st just to be sure. Then suddenly SES light comes on and the car is vibrating. Power was virtually gone ( I know these cars don't have much low RPM torque but this was bad..) I was accelerating but it felt like it was struggling. The clutch pedal had subtle but somewhat very noticeable vibration. I nursed it to the parking lot of my work (~1/4 mile from the stoplight where this happened) and parked it. Shut it off and turned it back on. No SES light but still a rough idle. The exhaust was making a pulsing sound and it was deep sounding coming from the rear (put my head near it). Looked under the hood while it was running and everything seemed normal. Sounded like it always did. The motor was moving but that's normal with idle. No NOTICEABLE leaks. I revved it to ~3k and it sounded like it had a hard time getting there. The car has never had any mechanical problems since I've had it except for a water pump that I replaced 2 months ago. My gas light is on but I was plannig to fill up after work and its never done this before when the gas light comes on (usually fill up at 1/4 tank anyway). Car is bone stock. What's going on? Injectors? Spark plugs? Filter/s?

Thanks
 
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#4 ·
Where do I go to do that? Will AutoZone do it? I know the stealership will.
Also, I've been researching and people having something like my problem are saying to replace the coils and plugs as well as checking MAF and fuel filter. These are all things that seem like they'd be causing this issue. Just seems weird that it happened out of the blue when everything was fine.
 
#3 ·
It seems like your engine went into "limp home" mode. This can be caused by a number of things, but the most likely is a failed ignition coil for one or more of the cylinders. These do wear out, and what you describe sounds like what I am suggesting. If any one of them is bad, replace all 6.
 
#6 ·
All of these suggestions are just guesses.. you need to have the codes read by a bmw specific scan tool. Otherwise you are just taking shots in the dark. You can probably find a local forum member (on this or other forums) willing to read your codes for free.
 
#7 ·
Indeed. I had AutoZone check my codes. Their reader brought back the following errors: p0304 and p0300.
The guy said that means #4 is misfiring and there is another random misfire.

Any other insight on these codes/problems?

I'm planning on replacing all 6 plugs and coils + cabin air filter and engine filter anyway since it seems like a fairly easy DIY.
 
#9 · (Edited)
P0300 is multiple cylinder misfire
P0304 is cylinder 4 misfire

Since it's a generic reader it doesn't specify whether the cylinder cut out or not.

I would say #4 injector, coil pack or spark plug since only one definite cylinder was in the codes.

You can swap these parts (one at a time) to another cylinder to see if the misfire follows to identify your problem part, if you're replacing all of them then no need to test.
 
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