early m20 ignition coil same as '91 535i?

[tim eh?]

I think I need to change this ignition coil :D - urgently!

http://www.bimmernut.com/forum/attachment.php?attachmentid=6547&stc=1&d=1233956046

http://www.bimmernut.com/forum/attachment.php?attachmentid=6548&stc=1&d=1233956046



It must be the original as realoem shows this one as "ended" (http://www.realoem.com/bmw/showparts.do?model=HC23&mospid=47402&btnr=12_0057&hg=12&fg=05) for my car.

A 06/89 build m20 uses a cylinder coil here on realoem (http://www.realoem.com/bmw/showparts.do?model=HC23&mospid=47402&btnr=12_0014&hg=12&fg=05)

However, a '91 535i m30 uses the same part as I have which has been replaced by another one.
http://www.bimmernut.com/forum/attachment.php?attachmentid=6549&stc=1&d=1233957203

At least it should fit right? For the cylinder one I would have to redo the wiring.

I tested it according to bentley it reads normally except secondary resistance [15(+) to centre tower] reads 9.0k ohms instead of 6.0...

But the symptoms are classic weak spark symptoms and I already replaced the distributor and rotor... probably way way way past due on the wires, too.

I can check those tonight - they look ok but looking good doesn't mean a thing to anyone in -20'C.

damn they are expensive - at least $100CAN for the coil and I bet $200CAN+ for the wires - and I read this thread on bosch wires as being crappy now (http://www.bimmernut.com/forum/showthread.php?t=38097), so what do you guys say - should I go for the 535i bosch coil and bosch wires or something else?

(as you can see, A/C remains low on my priority list :D)

[winfred]

it'll work, the round one from a e30 would also fill the bill

[E34-520iSE]

Mine has a round one on too. Looks like it's the original one.

HTH,

Shaun M

[tim eh?]

Thanks guys -

I ordered a "hexagon" coil from http://www.autopartsonlinecanada.com/ finally - NO DUTY!

It was easier than explaining to the guy that I don't want the "round" one. (sheesh...)

Checked the wires and plugs. Wires look good, no errant sparks, but I should replace them someday soon anyway. The plugs are getting dirty too fast, but it is evenly spread out so I think the coil is a good suspect. Past due anyway.

Doused the distributor, wires and coil in water and it ran fine hot and cold so I think I am safe so long as she starts, it only struggles below -15'c for a few minutes, maybe this is also the source of my very rare warmish-start problem. I'm impressed the original coil lasted 20 winters here.

So what's the deal? Why would they change the coil design on the same motor and then bring it back on the m30? I guess a spark is a spark... must be pretty standard for similar engines.... I really don't know...

I'm still not sure which wire set to buy.... can't I buy a set for like a ford escort or something? :D

[tim eh?]

well that was ridiculously easy even though it is cold out, i should have changed that a long time ago. i guess the round one would fit there only the protective cap and the rubber jacket (which don't come with the new one)wouldn't fit.

the car really seems to like it. it ran nice already but now it sounds... sparkier... (?) - it starts really nice anyway.

part# 12131742925 in case anyone ever wonders.

while i was shopping for it i noticed either bma parts or pelican parts (i forget) sells the factory (bmw) coil for around $100 which isn't much more than the aftermarket ones (i bought a bosch). they still make those? or is it a brand new but 20 year old part i wonder...

[Tiger]

Actually you can install any coil you want. There are alot of better coils out there on the market for around same price.

[tim eh?]

Actually you can install any coil you want. There are alot of better coils out there on the market for around same price.

oh well, the one i bought was less than $100can so not even 80 bucks... i have a brand new one for a dodge with an old 'slant' 6 cyl engine you mean i could have even used that?