E46 Spark Plug DIY

Originally Posted by WAM

Step 4
Now using your spark plug socket with at least a 6" extension bar, you can remove the plugs and replace the new ones.

I used a high temp spark plug lubricant/ anti-seize compund so I tightened the plugs until just firmly tight. The spark plug torque is 30Nm otherwise.

Repeat the procedure for all 6 plugs and follow the reverse procedure to replace the microfilter housing.

I found this link on replacement coils with a pretty strong claim of improved performance (quoted below). Any input???

http://www.bavauto.com/shop.asp

"The core windings inside these coils have been modified to increase firepower and promote a faster, more efficient burn. This gives your BMW increased torque in the lower range of RPM and more horsepower in the upper range. Exact improvements depend on the current condition of your BMW's engine, but you'll definitely feel the difference. They'll also improve your fuel economy. Plus they come with new spark plug boots, making them an even better value. Installation is a simple, do-it-yourself procedure that takes about 30 minutes. Instructions included."

I own a 2001 bmw 325i about two weeks ago i changed the spark plugs and boots on my bmw, however two week before that my car was running fine a little slow but fine untill i changed the spark plugs. So my question is do i have to calibrate the plugs? and if so, what tool do i need to get? I dont want to pay anybody.

SO GREAT! I just did this. Took me about 1 hour 20 minutes. Thanks for the detailed instructions. The visuals made it so easy.

NOTE: it was difficult getting the coil out. but with pulling it came out. ALSO I don't think the spark plugs have EVER been changed. So initial loosening was difficult as well. the rest of it was EASY!

NOTE: when removing the plastic housing covers where the bolts are to remove the cover, be careful on the sloped cover when popping off the bolt covers. I dropped mine down the engine to the bottom. I was able to retrieve it. But be careful, maybe use two hands, one to hold the screwdriver, and one hand on the bolt cover to control it from popping off.

NOTE: I would also suggest starting with the furthest away from the front of the car. They are more difficult to get to, the easiest being the first three. Get the difficult ones out of the way first, then the rest are super easy.

NOTE: ALSO So as not to confuse which coil went in what hole, I did one complete change, then moved on to the next. So only one coil was out at a time. It broke up the monotony that way too.

Posting a pic of the SP that came out of the car. 2001 330 Cic with 39K miles. Bought 2 years ago at 11k miles. Don't think the SPs were ever changed, but you can let me know... I'll probably change them more often now that I know how to do it.

Thanks again for the great informative post. IF YOU HAVEN'T DONE IT, it is SO EASY to do... Just follow this post and you'll be fine.

Tyler

Thanks to everyone who has posted to this thread. I'm going to attempt a coil swap tomorrow and feel reasonably secure I can handle it based on all the excellent information found here. My SES code indicated a mis-fire on cylinder # 1. I don't have a service manual and am not sure if # 1 is to the front or rear. Any information would be appreciated.

Cardinal5

Originally Posted by cardinal5

I don't have a service manual and am not sure if # 1 is to the front or rear. Any information would be appreciated.

I would like to know this as well . . . does anyone know?

Thanks!

Thanks for the write up OP. And FalconGuy I am with you 100%. The only reason to pull the plugs early would be to apply some anti-seize on the threads. 100,000 miles are a long way to wait to find a seized plug. Even though it would be along shot. I have never had good fortune with Bosch plugs. NGK's on the other hand rock.

I just swapped all my spark plugs. This post was helpful but a few things were not clear, in particular on the "pull up the silver clip" part. I ended up watching a youtube video and it all worked out!
Before the spark plug change, my car was running rough at idle (very rough on the last two days) and my service light had been on. As soon as I had put the last plug in, tied down everything, I tested it and it was running smoothly!
After 15 miles of driving and a few starts and stops, the service light is now off!
Very happy with this DIY job!

PS: I won't ever have to do this job on my 335d

Originally Posted by Fun MiLes

This post was helpful but a few things were not clear, in particular on the "pull up the silver clip" part. I ended up watching a youtube video and it all worked out!

I also tried to describe it and snap a picture of every step over here ...

- One user's pictorial DIY for replacing the BMW M54 engine spark plugs (1)

Quick question. Recently had my 325CI major serviced (75,000KM) at a mechanic that service mainly BMW and Mercs. Part of that was changing the spark plugs, would that make the car be not as responsive when accelerating if you don't use the right spark plugs? I think it would, what are your thoughts?

Cheers.

Originally Posted by alpinewhite325i

Just used this DIY...excellent job.

Let me just add that after 53,xxx miles, my plugs had virtually no wear. I still replaced them with the OEM NGK's, however now I know I won't ever need to replace them again.

I believe they are truly 100,000 mile plugs.

The condition/performance of a sparkplug has somewhat to do with "wear".....but not JUST to do with "wear". AGE is another factor.....and you can't see age on a plug, except for maybe some discoloration on the outside and on the threads that hold it into the cylinder head.

Plugs DO wear out......in invisible ways......on the INSIDE where you can't see.

Toss them after two years, whether they "look" worn or not. They ARE! What's 30 or 40 bucks? You want performance, right? I knew you'd say YUP!

Originally Posted by compusatman

Thanks for the write up OP. And FalconGuy I am with you 100%. The only reason to pull the plugs early would be to apply some anti-seize on the threads. 100,000 miles are a long way to wait to find a seized plug. Even though it would be along shot. I have never had good fortune with Bosch plugs. NGK's on the other hand rock.

Oh, come on! NGK vs Bosch is like Mac vs Windows. That's so last Tuesday.

Move on.........and just change your plugs........to ANYTHING NEW!

Originally Posted by New61n

Quick question. Recently had my 325CI major serviced (75,000KM) at a mechanic that service mainly BMW and Mercs. Part of that was changing the spark plugs, would that make the car be not as responsive when accelerating if you don't use the right spark plugs? I think it would, what are your thoughts?

Cheers.

It COULD make a difference.......but not as much as probably your imagination! (kidding...but, sort of not). I personally always get a strange feeling that my car's performance/output has changed every time either I or anybody else does any work on it. Just drive it for a week and try not to think about it.

The type of gas you put in it will have a much greater affect on performance; load her up with a tank of high-test (Sunoco 260 if you have it) and watch/feel her go!

Not trying to be prick, but you mentioned something about the spreading of misinformation so I thought it would be appropriate to mention that the area has no relevance to breaking force. More area does not mean more friction. Friction only depends on normal force and friction coefficient, regardless of the area.

Originally Posted by FalconGuy

There is no bigger/better spark or more complete combustion, if there was the MFG would be all over it since more complete combustion would gain lower emissions, more HP and huge tax advantages for pennies per car, it either sparks or it doesn't, no science or data at all to support that 4 prongs are better than 1,2, or 3.

Not to thread crap but its just bad info that gets past around a lot. Kind of like vented/slotted rotors ( with less braking area thus less friction material and correspondingly less braking efficiency) will somehow give better performance. They dont, never have, never will. Its a simple equation, how much surface area do the pads have to contact, take any away and the performance goes down.

One of the biggest waste of your DIY dollars and potentially the easiest to cause significant engine damage is using a plug other than that of the MFG's specs. The best part is the NGK OEM's are a few bucks each. People spend the price of a set of 6 OEM plugs for ONE Iridium or 4 prong or the latest rage plug, ask a mechanic, one you trust, dont take my word for it, he will tell you its snake oil.

Please dont think I'm calling anyone a liar or dumb, there is a lot of misinformation out there and this is something I know quite a bit about. Changing your plugs at 50K BTU is overkill, wasted money, if you can live with that then go ahead., but dont expect any tangible benefit, because you will not get any. You will one day, when the car wont start and after changing the failed plug /plugs then you will see the benefit, no sooner.

Its like a light bulb, it works or it doesn't, there is no in between