Which Spark Plugs..?

upstream

Regular Member
The M44 Massive
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Sep 5, 2014
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21
Hi all,

Just doing a bit of tinkering and decided to check my spark plugs. They look ok (a sort of light tan colour) but I have no idea how long they've been in there and thought it may be a good idea to change them.

The ones currently in there are NGK R R1 BKR6EK

I checked Halfords but my local store doesn't have them in stock at the moment. Are these the ones that BMW recommend? Are there any others just as good?

I'm happy to go with what the wisdom on here suggests.

Thanks in advance.
 

upstream

Regular Member
The M44 Massive
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Sep 5, 2014
Points
21
Turns out that my second closest Halfords had a set so I grabbed them and popped them in. I did notice though that whilst the packaging said for BMW M43, they didn't say M44.

On a quick round the block test nothing went "bang" so all's well ;-)
 

jonco

Zorg Guru (IV)
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British Zeds
The M44 Massive
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'98 1.9 Auto
Z

zedonist

Guest
Wrong both the BKR6EK and the BKR6EQUP are specified for the M44, as they are for all other engines in the range except the //M, how ever the upgrade plug BKR6EIX is the preferred plug from NGK and works very well in the M44.
 

vintage42

Dedicated Member
American Zeds
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Dec 24, 2013
Points
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Wrong... the BKR6EQUP are specified for the M44... the upgrade plug BKR6EIX is the preferred plug from NGK and works very well in the M44.
Do you have a reference for the statement about the BKR6EQUP?

I am aware that the BKR6EIX is used by some people in the M44. But after NGK noted their incompatibility with the M44's ignition system, I put in the BKR6EK.
 
Z

zedonist

Guest
I have the BKR6EIX Fitted in my M44 no problems, been in last 3 years, new set going in over the winter service because there cheap to do, not because they are worn out.

I would suggest your contact is not aware of his company website and technical information:

IMG_0271.PNG
 
Z

zedonist

Guest
It is strange, that NGK in the USA does not recommend the EIX for the Z3, but the UK does, I have now compared both websites, it would be interesting to know your contacts take on this?
 

vintage42

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It is strange, that NGK in the USA does not recommend the EIX for the Z3, but the UK does, I have now compared both websites, it would be interesting to know your contacts take on this?
He is not my contact, just an NGK technician who answered my questions two years ago.
In the email posted above, he said:
"The BKR6EK has a 6.0mm firing position with two ground electrodes and a 1K ohm internal resistor. The BKR6EIX has a 3.5mm firing position, with a single ground electrode and a 5K ohm resistor. The firing position might create some engine response lag, but the real concern in the 1K ohm resistor. The ignition in the Z3 is setup for a 1K Ohm resistor and the 5K resistor may cause random misfires... I would realistically not recommend the BKR6EIX for the Z3."
I think he is saying that 5K ohm resistance of the EIX is more than the Z3 coil pack was designed put a spark through, and can cause misfires. Perhaps that problem is only theoretical, as the Z3 seems to overcome it. But the two plugs have very different firing positions and resistances, so you would not assume they can be interchanged.
 
B

badman gee

Guest
It is strange, that NGK in the USA does not recommend the EIX for the Z3, but the UK does, I have now compared both websites, it would be interesting to know your contacts take on this?
Where were you today at Santa pod?
 
Z

zedonist

Guest
Well the UK obviously disagrees, or the EIX has been modified. I don't know how a spark plug can cause a random misfire, unless it stops working, it's the ECU and Cam Sensor that decides it's time to fire and the coil pack sends the charge down the cable and the plug fires. I have never had any random misfires reported in the three years they have been fitted.

My understanding is that resistors in spark plugs are there to remove electromagnetic noise, and should be used in cars with electronic engine monitoring and not using them can cause poor idle and misfires.

Sort of makes a case for the EIX to be used, as I don't have rough idle either.
 

vintage42

Dedicated Member
American Zeds
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Points
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... My understanding is that resistors in spark plugs are there to remove electromagnetic noise... I don't know how a spark plug can cause a random misfire, unless it stops working, it's the ECU and Cam Sensor that decides it's time to fire and the coil pack sends the charge down the cable and the plug fires...
The EIX would cause a misfire if the Z3 coil, which is designed to see a 1K ohm resistance, could not push a spark through the EIX's 5K ohm resistance. Maybe it's hard on the coil to push its charge through 5K ohms.
Worse, the charge has to go or dissipate somewhere. If it does not find an air gap elsewhere it can jump, it stays in the coil. Perhaps after thousands of miles, the accumulated effect of occasional random, intermittent, unfelt and un-sensed misfires causes a problem with the coil pack.
 
Z

zedonist

Guest
But they don't, your talking theory of a concept, that I have proved is not there or happening, and what's more NGK specify them as an upgrade plug from the original. It all ends up being a mute talking point.

From what I garner all NGK resistor plugs in the UK are 5ohm, perhaps the issue is only in the USA?

For the other M44 owners reading all we can say is there is a choice of three plugs available in the UK, and the part numbers are above, use the one that you feel comfortable with.
 
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