Ignition coils & spark plugs

[Tampa330i]

I doubt my plugs have ever been replaced, so I've been checking out some of the videos on removal and install, it doesn't look bad. Has anyone replaced the coils with performance ones? If so, notice any difference? Any recommendations on spark plug brand?
When I go to install, is it necessary to have a torque wrench for the plugs and coil bolts? I've never seen anyone torque a spark plug before. Then again, I've never seen a lot of things this car has. Just today I watched the sprint booster install video, who knew that the gas pedal isn't even a pedal anymore! My automotive understanding is about 10-15 years ago, and poor for even that time period.

[danewilson77]

I have never torqued a plug....everything is by feel for me.

I did torque front wheel bearing nuts though.

[kayger12]

I torque everything to spec, provided I can get the wrench on it- plugs, wheel lugs, oil filter housing cap...

Mostly unnecessary, but it makes me feel better. Figure I dumped the money on a torque wrench, might as well use it.

For plugs I use NGK.

[az3579]

I torque everything to spec, provided I can get the wrench on it- plugs, wheel lugs, oil filter housing cap...

Mostly unnecessary, but it makes me feel better. Figure I dumped the money on a torque wrench, might as well use it.

For plugs I use NGK.

Torquing is NEVER unnecessary. ALWAYS torque EVERYTHING properly. Especially spark plugs, Dane. You don't want to strip the threads in the head now, do you? :shifty

[Alphatek45]

I torque everything to spec, provided I can get the wrench on it- plugs, wheel lugs, oil filter housing cap...

Mostly unnecessary, but it makes me feel better. Figure I dumped the money on a torque wrench, might as well use it.

For plugs I use NGK.

#1 I use a little high temp anti seize on the threads as well.
Not sure what your mileage is, Tampa but its such an easy job I say do it!

[kayger12]

#1 I use a little high temp anti seize on the threads as well.
Not sure what your mileage is, Tampa but its such an easy job I say do it!

+1 on the anti-seize.

It really is an easy job. Plenty of peeps on here to help you out.

[billschusteriv]

A light coat of anti-seize - I recommend trying to keep it outside of the cylinder.

Oh - I like to make sure the block is cold when I do plugs - so I risk damaging the threads on the engine.

DW and I have a calibrated arm... Hehe... (No..srsly...)

After looking (and using) at a lot of the torque specs on e30 repairs, I find that knowing them can be rather helpful - to either prevent overtorquing and damaging the fastener & threads or undertorquing and risking something else entirely (e.g. losing a wheel).

Wrench tight varies with length of your wrench (I associate this with force and lever action from physics lessons).

Getting a torque wrench in some of the spots under our car can be challenging or impossible without removal of a lot of interference parts.

[az3579]

Getting a torque wrench in some of the spots under our car can be challenging or impossible without removal of a lot of interference parts.

In some cases, depending on the part, it's worth removing that crap to get to it.
In other cases, I think there are things like flexible extensions and whatnot. I don't know how that affects the torque specs though.

[billschusteriv]

In some cases, depending on the part, it's worth removing that crap to get to it.
In other cases, I think there are things like flexible extensions and whatnot. I don't know how that affects the torque specs though.

Agreed. If you can get the wrench on it, by all means.

I was thinking specifically of the fill plug on the side of the Getrag transmission. On the e30, it's a fastener with a recessed hex (17mm IIRC) and its nearly impossible to get a torque wrench on it unless you drop the trans.

Most torque wrenches are calibrated to read the amount of force you are applying at the head of the wrench. Any change (universals, crows feet) will have some effect on the force you are applying.

After thinking about it, there is a tool for every application. I currently use a deflecting beam torque wrench - if I would use a click type torque wrench (uses a calibrated clutch mechanism that "slips" when the torque setting is reached) - it probably would be the appropriate tool to use for reaching the fill plug on the side of my MT.

I think I may be taking this a bit OT. A good discussion to have.

I hope our sidebar helps Tampa.

[danewilson77]

In some cases, depending on the part, it's worth removing that crap to get to it.
In other cases, I think there are things like flexible extensions and whatnot. I don't know how that affects the torque specs though.

http://i249.photobucket.com/albums/gg220/ozhopper/STUFF%202010/torque5.gif

[Tampa330i]

I hope our sidebar helps Tampa.

I once saw a connecting rod cap blow through the side of an engine because it wasn't torqued properly. I never underestimated the importance of tightening to the proper spec after that, so the more talk of torquing, the better.

[shadowpuck]

i will make a good effort to use a torque wrench and spec on anything i can easily use the torque wrench.
i've also worked with plenty of folks that do not need the wrench and can be very consistent with their torque.

myself, i'm not to that level - so, i try to use the wrench when/where possible. the specs and wrench exist to ensure a consistent install.

as to plugs - agreed on NGK, available reasonably affordably at advance, and other parts stores.
agreed on the light use of anti-seize, and doing it while the motor is stone cold.

i have yet to see any evidence that shows the "performance" coils help or hurt. i'd say as long as yours are fine, no codes, no issues, i wouldn't worry about it.....
i'd replace the boots if yours look damaged....

[az3579]

http://i249.photobucket.com/albums/gg220/ozhopper/STUFF%202010/torque5.gif

My mind just went into meltdown. Irrecoverable data...

*Blue screen*

[danewilson77]

Its basically saying that you want to torque something to 135 in-lbs......but you have extended the overall length of your torque wrench by 1.5"......so....what would you need to read on the dial....to torque the nut to 135in-lbs?

117 in-lbs.

Its actually a fairly useful equation...and this can be mitigated, in the example above, by turning the extension at a 90 degree angle to the torque wrench.

In this manner you will not be lengthening the overall effective length of the torque wrench.

[billschusteriv]

http://i249.photobucket.com/albums/gg220/ozhopper/STUFF%202010/torque5.gif


My mind just went into meltdown. Irrecoverable data...

*Blue screen*


Its basically saying that you want to torque something to 135 in-lbs......but you have extended the overall length of your torque wrench by 1.5"......so....what would you need to read on the dial....to torque the nut to 135in-lbs?

117 in-lbs.

Its actually a fairly useful equation...and this can be mitigated, in the example above, by turning the extension at a 90 degree angle to the torque wrench.

In this manner you will not be lengthening the overall effective length of the torque wrench.

Thanks Dane. I was looking for a similar graphic, but was unable to find one online. I should've gone downstairs for my Engineering Principles manual....

Dane's graphic and formula provides a great example of how the actual force applied is different from the indicated reading on the torque wrench. A difference of 115%.... If you'd go to 135 inch-pounds indicated, you will have applied 155 inch-pounds to the fastener. Maybe not enough to snap the bolt, but what about the stresses we've subjected the bolt to?

I hate having fasteners fail or snap upon removal or reuse - I've been stuck in this place a couple times during a project and found myself unable to put the car back together.

[danewilson77]

Good idea Bill. I should have thought of explaining it....lol.

[billschusteriv]

It's all good. I got your back. You got mine. It works.

[Tampa330i]

<3 physics. I prefer the weirder varieties such as theoretical, astro, and quantum. It boggles my mind trying to comprehend reality. Not a day goes by that I don't spend at least a moment trying to figure out how gravity works.

[kayger12]

Higgs Boson, FTW!

[Tampa330i]

Higgs Boson, FTW!

Did they find that, yet? I'm leaning towards there never being a graviton. Even if the 3 other forces can be proven to 'work' because of particles, it's doesn't mean gravity has to.

I didn't see that anyone has tried performance ignition coils yet, maybe I'll put it on the list. I'll go with ngk plugs and new boots.

[az3579]

I don't see the high performance coils doing anything better than the OEM ones.
I once had high performance wires installed in my E30 (used cap and rotor at the time) and they made no difference.

[GERMANIAC]

My car has been running rough at idle for the past few days and now my Service Engine Soon light came on. In researching this a little on the internet it looks like it could be a bad ignition coil or spark plug. You guys have any comments on this? Thanks!

[kayger12]

Could be. Best way to narrow down is to get the codes read.

If you get a misfire code with a cylinder #, you can swap coil packs and verify that you have a bad pack.

How long have the plugs been in?

When was the last time the valve cover gasket was changed?

[GERMANIAC]

I believe the plugs are original. I found some info from bmp design showing how to verify if you have a bad coil. I think I will try this first and proceed from there.

http://www.youtube.com/watch?v=z37jl4HXQjg

[kayger12]

Well that's certainly one way to do it.

Let us know how you make out.

If you don't narrow it down with that, let us know if you get the codes read. Could be several other things besides plugs and coils.

[Newjack]

Well that's certainly one way to do it.

Let us know how you make out.

If you don't narrow it down with that, let us know if you get the codes read. Could be several other things besides plugs and coils.

Fuel injectors are also another possibility. But if your car is around 100K miles, its probably the spark plugs or ignition coil pack.

As for spark plugs, does anyone know how big the gap is supposed to be?

[GERMANIAC]

I got an error code P0171 - system too lean...

http://www.obd-codes.com/p0171

Possible solutions listed in the attached link - anybody else ever receive this code...

[danewilson77]

Yes. Both e46's I had. It was caused by torn intake boot. Tear was on smaller hose that goes to icv.

Inspect intake stream for a leak.

HTC Thunderbolt+TT

[kayger12]

Yep-- most likely the intake boot like DW said.

Common issue. Easy fix.

[MrMaico]

Fuel injectors are also another possibility. But if your car is around 100K miles, its probably the spark plugs or ignition coil pack.

As for spark plugs, does anyone know how big the gap is supposed to be?

The style of plugs used in our cars have a preset gap from the factory. No need to adjust the gap.

[GERMANIAC]

I inspected the intake boot along with the small rubber hoses coming out of the top. The smaller of the two is cracked. I taped it up to test it and have noticed improved idling. I hear AutoZone carries replacement tubing sizes. I also noticed a small tear in the bottom of the hose feature where these hoses hook into. May need to replace the entire intake boot as well. SES light still on though...

[kayger12]

I inspected the intake boot along with the small rubber hoses coming out of the top. The smaller of the two is cracked. I taped it up to test it and have noticed improved idling. I hear AutoZone carries replacement tubing sizes. I also noticed a small tear in the bottom of the hose feature where these hoses hook into. May need to replace the entire intake boot as well. SES light still on though...

Do you have any pics?

I think the SES will clear on its own after a certain number of trouble-free cycles once the problem is fixed, but not sure on that one.

[aurelius]

Updated spark plug torque spec for M54 motor. Click HERE (http://www.zhpmafia.com/forums/showthread.php?4787-BMW-M54-Spark-Plug-info-updated-torque-spec-amp-more) for details.

[webster]

i've added the performance coils and NGK plugs to my (ever-growing) list...

[Newjack]

i've added the performance coils and NGK plugs to my (ever-growing) list...

Performance coils and plugs wouldn't make a difference if you are running a stock setup right?

LG Revolution + Tapatalk

[webster]

eh, probably not, but i'd feel better knowing they'd been put in. def not a priority.