I changed my plugs on the 95 M3 this weekend and man were the old ones bad! Some werent as tight as others and one coilpack was loose. #1 and 5 had a bit of oil on them (wet) and the others were normal color. I got the NGK's that realoem called for, which were different than what was in the car. The new ones had 2 whatchamacallits over the electrode instead of one. Now, at idle, it pops very faintly every so often. Enough to feel it in the chassis when sitting in the car.

My pops showed me a little trick with a piece of paper infront of the exhaust: naturally the exhaust will push the paper away making it "flutter" When it pops, it sucks the paper towards the exhaust. Is this valve seals? Rings?:help

Other than this at idle, the car runs great, (minus the fact that I think my vanos is going to crap)

Any advice/input would be awesome.

TIA

i think when it sucks the paper that possibly means you have bent valves

^ could be true, a bent valve wouldnt close all the way causing a vacuum in your exhaust

Then why would I notice it after I changed the plugs and never before? I could maybe see a few bad valve seals but not bent valves.

I have a similar issue and it's driving me crazy.

Last November, I replaced the valve cover and the plugs in my '95 M3. Ever since, my idle has 'popped' occasionally like you are experiencing.

Thinking it was a bad plug, I replaced all the plugs again. Same problem. Then I replaced all the coil boot covers. Didn't fix it... I found some small cracks in my intake elbow boot and replaced that. Nope... Cleaned my MAF. Nope... But I replaced my fuel filter last weekend and it seems to have improved the situation. Less pops now...

I'm thinking I might have a vacuum leak so I'm still hunting for that. Anyway, it's really weird and the timing where it happened right after that initial plug and valve cover change...

It won't be 'bent' valves. If this were the case, it would be popping and fluffing like crazy. Bent valves are very rare.However, carbon build-up on the valves and head can cause the exhaust valves to occasionally seat badly, allowing the piston to pull exhaust back into the cylinder on the induction stroke, which causes the popping. You may be using a slightly different heat range plug which is not doing the same job as the old ones. If #1 and #5 were oily, you can bet the heads are coked up from burning oil. Probably worth doing a compression check and a cylinder leak-down test to check the condition of your rings and valves.
'Valve seals' are the valve stem seals and are little nylon sleeves which fit over the valve stem and prevent oil from the cam area travelling down the valve stem into the cylinder. Leaking valve stem seals may be contributing to the oil contamination of #1 and #5 also.

My friend was having a misfire problem on his audi with coil on plug ignition. I told him to try smearing some silicone grease on the boots that connect to the spark plus. After that it was gone. The rubber boots looked fine but were letting the spark arc out of them sometimes.

If #1 and #5 were oily, you can bet the heads are coked up from burning oil.

Not necessarily, but could be, depending on what he means. Its hard to tell sometimes, but he may mean that the tops of the plugs are oily from a leaking valve cover gasket, which is common on many BMWs. If he means that the electrode portion is oily, then yes, the cylinders are probably carboned up.

The oil was on the electrode side of the plugs. #5 had more than #1 on it.

if its just carboned up, what could clean them?

Also regarding the "colder plug", what NGK's are recommended? I bought the ones that realoem had for the 95 M3. Are these not the best ones to use?

Go back and check all your plugs. Look closely at the porcelain insulators for cracks. I've had plugs new right out of the box that were cracked. Then recheck all your gaps. I've also had plugs come out of the box with the side electrode bent over.

Also, are the plugs gapped correctly?

I will check the plug gaps again. What is the gap supposed to be for the "dual electrode" plugs?

The plugs should be gapped to .032" for the ngk multi-ground plugs.

The NGK BRK6EK plugs are dual spark and are non adjustable gaps, right? That is what I bought from realoem. Im not sure how to check the gap on those because I cant fit my gapping tool (round one from AZ) between the 2 prongs.

Can someone fill me in here? How do you properly gap these plugs??? Once they are out i will recheck for cracked ceramic.

Please help me with this because I leave for the tail of the dragon on Friday and want my car to be running properly.

What other plugs can I replace these with? my car is mostly stock with just an intake and exhaust.

:help

I'm pretty sure the dual electrode plugs are set at the optimum gap right out of the box - you shouldn't have to adjust them. Because of the curved end on the electrode only a wire gap guage (as opposed to the common plate type) will give you an accurate measure.
As I said previously if the plugs were oiled or sooty, then you have either a valve stem seal leak or bad rings on those cylinders.

Thanks for the info. Are there any other plugs that I can use that dont have the dual electrode's? Something that can be bought from the local parts store to see if this fixes the problems?

Since I NEVER had the misses before changing the plugs, I want to try to replace the plugs with a different set to see if the misses go away before I look at anything else.

I am having the exact same problem right now. The other day I had a cylinder misfire and I took it to Autozone. They hooked it up to the ODB and told me cylinder number 5 misfire. First thing I do is switch ignition coils, they're definitely good. Yesterday I changed the spark plugs. They ran out of 4 prong ones so I went with the 2 prong. (this is the first time I changed the spark plugs and the person that had it before me had 4 of 1 kind (of spark plugs) and 2 of another, the 2 were 5 and 6. Today I have noticed that my car seems to hestitate and I can feel it jerk sometimes(its definitely there) when I start to accelerate. Now when I changed the spark plugs I noticed that the seals around 5 and 6 were just a little bit oily. but I'm not worried about that since it was such a tiny amount. (i put in Bosch platinum+2 spark plugs)
So is it possible that the spark plugs could be doing this since I went from +4 to +2 prong???

Yea I could make another post but it seems like we have the same problem.

Also I added SeaFoam in the gas tank today (before I came across this post) and the car is sputtering and choking but I'm expecting to have to wait for the next tank of gas to really see/feel the effects of it (Cleaner fuel injectors???).

wow thats a long post... so for everyone that didn't read it...
Is it possible that my car could be hesitating/sputtering even more because I changed the spark plugs from +4 to +2 prong???

I'm planning on replacing the fuel filter next. any help will be greatly appreciated

Im curious to find out what the dealer says whe nI call to see if there are any other plugs that I can use on the M. If I cant get an answer either from them of from someone here on the board before Thursday about the a different set of plugs that I can use, I am just gonna get another set from a local store and try my luck with them.

What is the torque spec of the plugs? something like 17 lbs, right? (I dont have my Chilton in front of me)

So I got off the dealer and they also said that the Bosch F7LDCR plugs will work.

Does anyone know the heat range for these 2 plugs? in the archive's I found this:

parad0x06-21-2006, 04:06 PM
I just talked to the parts person at my local bmw dealership and asked about proper spark plugs for my 92' 325I, and he replied with the standard Bosch F7LDCR. I had as well told him that I had just purchased some NGK BKR6EK and what he thought of them compared to his bosch ones from the dealership, and he said that the NGK's are one temperature colder? and that running them would just damage the oxygen sensor I was just purchasing from them.

Soo.. is what he said truly true? Does anybody know for a fact if the ngk's are a step colder then the bosch ones they were offering me? What kind of consequences are there to running colder ones (loss mpg, rich afr, worse ignition sparking?)? Should i return the ngk ones and go with the standard bosch plugs instead?

qidm6706-22-2006, 03:21 AM
go with the bosch. Many people have had great experiences with Bosch and NGK, more people will tell you to go with NGK. But I would go with Bosch since they can run more 100K on platinums. I have platinums +2 myself.

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sonnex2106-22-2006, 06:48 AM
in the UK we recomend NGK but bosch for M cars

So I think Im gonna try the Bosch and see if they burn a little hotter and see if that fixes my issue.