Bosch Ignition Coils - new

[shogun]

BMW p/n 12131286087 round type, aka rod-type Bosch 0 221 118 335 .Part 12131286087 (Ignition coil) was found on the following vehicles: E23: 733i,735i,732i,735i, 745i ; E24: 633CSi,635CSi, M6, M635CSi; E28: 528e,533i,535i,M5,525e,520i ; E30: 325e, 325i, 325ix, M3, 320i, 316i, 318i, 320is; E32: 735i/L,750iL,730i/L M30B30; E34: 525i,530i M30B30, 535i,520i,518i; E36: E36 316i Sedan, Europe, E36 318i Sedan, Europe. Also used in the first built years E32 750 with M70 V12, here a picture from a 1987 750i engine bay http://img1.auto-motor-und-sport.de/BMW-750-i-E32-Baujahr-1987-19-fotoshowImageNew-d9cd5a33-303169.jpg Used also in: ALFA ROMEO: 60623365; Lancia/FIAT: 60572202, 60623365; Porsche 928: 928 602 116 00; Volvo 9438231

$70/piece plus economy shipping from Japan, Shipping Weight approx :3 lb., 0.882 kg
8682


Bosch ring type ignition coil for cylinders 7-12 on M70 engine E32 750, E31 850, BMW p/n 12131742926, Bosch 0221502010, for cylinders 1-6 # 12131742925, Bosch 0221502009 was found on the following vehicles:
E31: 850Ci, 850CSi; E32: 750i/L,730i/L M30B30,735i/L,750iLS; E34: 535i, M5 3.6,520i,525i,530i M30B30; Z1: Roadster, Europe
8715

$70/piece plus shipping, Shipping Weight approx: 3.00 lb.

Please contact me by PN with country and zip code so that I can inform you total including shipping.

[shogun]

What happens when a coil dies..... copied from an E31 forum:Had an owner have his 1991 Canadian spec 850 towed here as it was running on 6 cylinders. Car has around 230k kms (142k miles) on it. Ultimately discovered the passenger side coil had spilled its guts and self destructed as shown:
http://i171.photobucket.com/albums/u305/Wuffer44/IMG_0374.jpg
Which in turn, took out the corresponding DME:
http://i171.photobucket.com/albums/u305/Wuffer44/IMG_0375.jpg
Once both replaced, car started on all 12 but on road test, idle wouldn't drop below 1000 rpms and car was surging violently. Replaced EML and all is now better. This is not the first puking coil we have seen up here that has taken out a DME as well but the first to affect the EML. Perhaps a cautionary maintenance replacement of the 25 year old coils may prevent this expensive failure.
-------------------------
Just as a follow-up. This was not an isolated case - it was the 5th E31 that I have had to do this diagnosis and repair on over the last couple of years. Other 4 were lower mileage J-specs and a US spec 6-speed car. I don't mind as I have plenty of coils and DME's on hand at the moment but I strongly urge you to replace your coils as a maintenance item. Using either OEM Bosch or aftermarket MSD 8207's will provide a stronger spark than your tired, worn out 20-25 year old OEM coils, improving reliability and even fuel economy and... maybe eliminate the additional cost of DME/EML replacement as well.... just my $.05 worth.
-------------------------
What would you gents say is a good safe interval? From my recent fuel pump conversations it was suggested fuel pumps get replaced approx every 10 yrs as maintenance items. Would you say half that for coils? 5 yrs despite mileage?
------------------------
I have replaced at 35,000 - 40,000 miles. That works out to every 18-24 months.
---------------------------

[shogun]

From Hella Techworld:
INTERNAL SHORT CIRCUITS : Overheating of the coil caused by the aging process, a faulty ignition module, or a faulty output stage in the electronic control unit.
FAULT IN THE VOLTAGE SUPPLY: The coil charging time increases on account of the voltage supply being too low, this can lead to premature wear or overload on the ignition control unit or the output stages in the electronic control unit. This can be caused by faulty wiring or a weak battery.
MECHANICAL DAMAGE: Damage to the ignition cables caused by marten bites. A faulty valve cover gasket and resulting engine oil leaks can damage the insulation of plug slot coils. Both of these causes lead to sparkover, and thus premature wear.
CONTACT FAULT :Contact resistance in the wiring due to humidity penetrating in the primary and secondary area, also frequently caused by engine washing or the use of grit in winter.
3 SYMPTOMS OF A FAULTY IGNITION COIL: SYMPTOMS
•Engine does not start
•Vehicle misfires
•Poor acceleration or loss of power
•Engine control unit switches to limp-home mode
•Engine warning lamp lights up
•Fault code is stored

4 MEASURING THE IGNITION COIL: BASIC PRINCIPLES
Dismantled state
There are different ways of checking the ignition coil:
Testing the resistance values of the coils using the ohmmeter.
Depending on the ignition system and ignition coil design, the following reference values apply: (observe the manufacturer's specifications)

Cylinder ignition coil (transistor ignition system)
Primary: 0.5 Ω–2.0 Ω/Secondary: 8.0 kΩ–19.0 kΩ

Cylinder ignition coil (electronic ignition system with map-controlled ignition)
Primary: 0.5 Ω–2.0 Ω/Secondary: 8.0 kΩ–19.0 kΩ

Single-spark or dual-spark ignition coil (fully electronic ignition system)
Primary: 0.3 Ω–1.0 Ω/Secondary: 8.0 kΩ–15.0 kΩ

PRACTICAL TIP
Note: If a high-voltage diode is built into an ignition coil to suppress sparks, it is not possible to measure the resistance of the secondary coil. In this case, the following method is helpful:
Connect a voltmeter in series between the secondary winding of the ignition coil and a battery. If the battery is connected in the diode's conducting direction, the voltmeter must display a voltage. After reversing the polarity of the connections in the blocking direction of the diode, no voltage must be displayed. If no voltage is indicated in either direction, it can be assumed that there is an interruption in the secondary circuit. If a voltage is indicated in both directions, the high-voltage diode is faulty

Installed state, the following checks can be used:
Visual inspection
•Check the ignition coil for mechanical damage
•Check the housing for hairline cracks and sealant leaks.
•Check the electrical wiring and plug connections for damage and oxidation.

Check the electrics using a multimeter or oscilloscope
•Check the voltage supply to the ignition coil
•Check the triggering signal from the ignition distributor, ignition control unit, or engine control unit
•Illustration of the high-voltage curve using an oscilloscope or ignition oscilloscope

Testing with the diagnostic unit
•Read out the fault memory of the ignition system or engine control
•Read out parameters

During all testing work on the ignition system, please note that faults established during tests with the oscilloscope are not necessarily faults caused by the electronic system; they can also be caused by a mechanical problem in the engine. This may be the case, for example, if compression is too low in one cylinder, which means the oscilloscope shows the ignition voltage for this cylinder to be lower than that of the other cylinders.

NOTE : Although "diagnosable engine management systems" are installed in today's vehicles, a multimeter or oscilloscope must be used when checking ignition systems. In order to interpret the displayed measuring results and figures correctly, additional employee training is usually required. One important pre-requisite for successful diagnostics is a careful visual inspection at the beginning of the troubleshooting process.

Link with pics of damaged ignition coils: https://www.hella.com/techworld/us/Technical/Car-electronics-and-electrics/Check-Ignition-coil-2886/

The ones for my M70 engine are Ringeisenzündspulen, ignition coil for transistor systems, TCI-ignition coil
primary coil : 0,5 Ohm between terminal 1 (-) and 15 (+) / secondary coil: 6,0 kohm,between terminal 15 (+) and 4 (ctr) on case of old Bosch p/n 2051118335
or
primary coil: 0,37 Ohm between terminal 1 (-) and 15 (+) / Secondary coil: 9kohm, between terminal 15 (+) and 4 (ctr) on case of old Bosch # 20510171101

newest # for M70 for example Bosch 0 221 502 010 Ignition Coil for Cylinders 7-12; M70 V12 cylinders 1 to 6 Bosch 0 221 502 009, BMW 12131720877

[shogun]

here the next reported damage on an E31 850 by a bad ignition coil, Bosch Motronic 0261 200 352 M1.7 for M70, also the DME component 1501 was burnt.
https://drive.google.com/file/d/1rOeUKEtYfhSP8BOFT1t2URIYZO3fwvmm/view
https://drive.google.com/file/d/1s0AvEI07KeiqmsRxSPdwdu8AldhF9i2n/view
https://drive.google.com/file/d/1s0AvEI07KeiqmsRxSPdwdu8AldhF9i2n/view
comment: today one of my DMEs started to smell burned and when I opened it, it showed that a component (transistor ?) is burned. See attached pictures. Do you know what this component does and the number/type? I thought maybe I can repair it.It happened just after I used INPA to check the DMEs Lambda values. I also tried to activate the lambda sensor heater and fuel valves from INPA before I started the car and I wonder if this maybe caused the damage. Before I started the car, I removed the plastic cover to check the lambda sensor heating relay that sits next to the DMEs, that's how I immediately noticed the smell and saw some smoke. I know this box is air-cooled but I can't imagine that this caused the fire.

[shogun]

New ones on stock, especially BMW p/n 12131286087 round type, aka rod-type
Part 12131286087 (Ignition coil) was found on the following vehicles:
E23: 733i,735i,732i,735i, 745i
E24: 633CSi,635CSi, M6, M635CSi
E28: 528e,533i,535i,M5,525e,520i
E30: 325e,325i,325ix,M3,320i,316i,318i,320is
E32: 735i/L,750iL,730i/L M30B30,
E34: 525i,530i M30B30, 535i,520i,518i
E36: E36 316i Sedan, Europe,E36 318i Sedan, Europe
Used also in:
ALFA ROMEO: 60623365;
Lancia/FIAT: 60572202, 60623365;
Porsche 928: 928 602 116 00;
Volvo 9438231