BMW E46 Fanatics Forum banner

1 - 13 of 13 Posts

·
Registered
Joined
·
61 Posts
Discussion Starter #1
just had a cylinder misfire (no fuel) first time. slight rough idle before a small vibration on pedals while sitting at lights. any ideas or previous experiance in this field?
 

·
Registered
Joined
·
10,204 Posts
Swap the coil on the #3 cylinder with any other cylinder. DO NOT SWAP LOTS OF STUFF ALL OVER THE PLACE, just take the #3 coil and put it on #1, and the #1 coil on #3. Drive the car for a while and see if the problem remains on 3, or moves to 1.

If the problem moves, the coil is bad. If it stays on 3, then you have a plug or fuel injector problem. Pull plugs first because they are easy, cheap, and have a limited life. Injectors are difficult, expensive, and should last a very long time. But don't do anything until you swap the coil with another one.
 

·
Registered
Joined
·
10,204 Posts
If you gotta ask...

Sorry.

Coils provide the spark for the spark plugs. Back in the days of old, right after the first wheel was invented, they used one coil, and a distributor to send sparks to each of the spark plugs. Now they use a coil for each cylinder. Works way better. More expensive, but waaaay better. Did I say it was better? I just wanted to mention that before I forgot.

Your engine has a cover along the top that has giant BMW molded into it. There are small round covers that you pry off with a screwdriver to expose a 10mm nut underneath. Two covers, two nuts -- you might find that the filter for the Cabin Air is in the way, and you can remove this pretty easily if you need to. You will have to remove the air filter housing at the base of the windshield to replace the spark plugs, but not to test the coil -- which I am getting to.

Remove the cover on the top of the engine and you will see a row of ignition coils smiling up at you. Each coil is held on by two 10mm nuts. #1 is the front, #6 is in the back, the others are in order. Count back to #3 and remove the coil, if you want to inspect the plug, you can, but for now just leave it alone unless it is wobbliing in its hole. Also remove the coil on the front, #1 Cylinder, and put it on the #3 that you took off, and put the #3 onto the #1. You do not have to put the cover back on.

Drive the car for a day or two until the CHECK light comes back on, and read the codes again to see where the misfire is. AutoZone will sell you a code reader for less than the price you would pay the dealership to extract codes twice, and you can use the reader on any car made for the 1996 model year or after. AutoZone also has a tool loaner program where they used to let you borrow the scan tool, but I can't say with any certainty that they still do this.

I have my own scan tool, and I find it to be as important to my tool collection as my allen keys and sockets. I don't see how anybody can even own a car today and not have a scan tool. Well. I don't see how anybody can own a car and a box full of tools that doesn't have a scan tool among them, and pretend to actually fix anything on the car.

Since you had to ask, which coils, I'm inclined to suggest you need help.
 

·
Registered
Joined
·
61 Posts
Discussion Starter #6
ya sorry it was a dumb question lol but thank you for the informative repsonse lol! i will check now. i have a code scanner already cause my friend is usually the one who does the work on my car! thanks
 

·
Registered
Joined
·
10,204 Posts
ya sorry it was a dumb question lol but thank you for the informative repsonse lol! i will check now. i have a code scanner already cause my friend is usually the one who does the work on my car! thanks
Make sure he's around and shows you the ropes. This is a very basic thing to do, and asking, "which coil" tells me that you have not spent much time under the hood.

I'm not dissing you, I'm just sayin that you need to respect the learning curve that you are embarking upon. There is much to learn, Grasshopper. Be patient, and don't strip out the aluminum head on your car.
 

·
Registered
Joined
·
61 Posts
Discussion Starter #8
yep ill freely addmitt that im cartarded. and these are ignition coils we are talking about right? how much do they retail for usually? and finally is the car still safe to run?
 

·
Registered
Joined
·
28,945 Posts
If you gotta ask...

Sorry.

Coils provide the spark for the spark plugs. Back in the days of old, right after the first wheel was invented, they used one coil, and a distributor to send sparks to each of the spark plugs. Now they use a coil for each cylinder. Works way better. More expensive, but waaaay better. Did I say it was better? I just wanted to mention that before I forgot.

Your engine has a cover along the top that has giant BMW molded into it. There are small round covers that you pry off with a screwdriver to expose a 10mm nut underneath. Two covers, two nuts -- you might find that the filter for the Cabin Air is in the way, and you can remove this pretty easily if you need to. You will have to remove the air filter housing at the base of the windshield to replace the spark plugs, but not to test the coil -- which I am getting to.

Remove the cover on the top of the engine and you will see a row of ignition coils smiling up at you. Each coil is held on by two 10mm nuts. #1 is the front, #6 is in the back, the others are in order. Count back to #3 and remove the coil, if you want to inspect the plug, you can, but for now just leave it alone unless it is wobbliing in its hole. Also remove the coil on the front, #1 Cylinder, and put it on the #3 that you took off, and put the #3 onto the #1. You do not have to put the cover back on.

Drive the car for a day or two until the CHECK light comes back on, and read the codes again to see where the misfire is. AutoZone will sell you a code reader for less than the price you would pay the dealership to extract codes twice, and you can use the reader on any car made for the 1996 model year or after. AutoZone also has a tool loaner program where they used to let you borrow the scan tool, but I can't say with any certainty that they still do this.

I have my own scan tool, and I find it to be as important to my tool collection as my allen keys and sockets. I don't see how anybody can even own a car today and not have a scan tool. Well. I don't see how anybody can own a car and a box full of tools that doesn't have a scan tool among them, and pretend to actually fix anything on the car.

Since you had to ask, which coils, I'm inclined to suggest you need help.
On behalf of the forum, thank you. This is the type of response we all need every now and then :thumbup:
 

·
Registered
Joined
·
126 Posts
not to thread jack but i got a cylinder 2 and 6 misfire, electrical code, intake code, fuel code, and ecu code! my car wont stay running for sh*t i had to get it towed. it broke down while i was driving. still not sure what happened...
 

·
Registered
Joined
·
4,792 Posts
OP, check your air intake tubes. probably have one torn. can get both upper and lower for around $30 at most dealerships.
 

·
Registered
Joined
·
10,204 Posts
With a single cylinder misfire, it is unlikely that it is a a tear in a boot. Normally the tears will cause a lean condition and multiple misfires, it would be a rare break to have a misfire on a single cylinder due to a leaking boot.

As for thread jacking, you have an entirely different problem than the OP. You could have a torn boot or broken hose, or any number of things.

To the OP, yes, we are talking about ignition coils.

The coil is the coil itself, and a boot-like thing that contains the rough equivelent of the spark plug wires of the days of yesteryear. The boot is more likely to be the problem than the coil itself. But before you care about dialing in on the coil or the boot, you need to swap the known bad part with a suspected good part, then walk away and watch for a while.
 

·
Registered
Joined
·
10,204 Posts
Here is an excellent resource for parts information, not the best place to acquire parts, but you can find every part there ever was, and then shop around for price... In your case, you want to know about ignition coils and the boots that connect the coil to the plug, this site will tell you more than you ever drempt of asking...

www.penskeparts.com

You can find the same information at realoem.com. Once you know all there is to know about a part, you can shop price at autohausaz.com, pelicalparts.com, rockauto.com, and many more.
 
1 - 13 of 13 Posts
Top