1987 325E ECU died

gbradcsi · 10-14-2002, 02:04 PM

Hi,
I changed from the Bosch multi-prong plaltinum plugs to the correct silber plugs and during this process i left the oil dipstick partially out. when i started the car next day i saw a blue cloud of smoke that enfulfed the car. it was bad. the car never ever smoked before and uses next to no oil, and after i drove the car the smoke stopped coming out of the exhaust, after a 16 mile drie at ~ 60 mph i shut the car off for 3minutes and after this it would not start. i wiggled the front sensor wires and it started, but only drove for only a 1/2 a mile before it cut out. i bypassed the sensor TempII with a 270 ohm resistor and the car ran fine for awhile, but it stopped again after ~ 5 minutes of driving.

i had a spare ECU ....027 and i plugged it in and the car has been running ok for the last 2 days.

my question is: because the dipstick was out did it suck oil into the valves, because of the vacuum change? why did the ECU die?

the confusing part is that the plugs were not black with carbon, but wet, like oil and it was a clear liquid, so it was not gasoline.
any ideas>

i have 223,000 miles and the compression is ~175 psi on every cylinder. the top end was done at 160,000 miles.
The plugs are dry again.

thank you for any information on this.

Garry [confused in NV]

Wayne 962 · Wayne 962's Garage

Hi Gary, I can indeed see how this can get confusing. Let me try to shed some light:

When you leave the dipstick/cap off, the car does have a huge vacuum leak. This will cause the car to typically run rich, or even not run at all (as is the case with the 1.8 Porsche 914s). This running rich may be the excess fuel that you see on your plugs. The mixture may be too rich to burn when you are trying to start it.

I would suggest that you restore everything back to the point where it was running good. Use the old plugs if you need to. I'm not sure which plugs you have now, but if you don't have the correct gap and heat range, it will affect the performance. (did you gap the plugs before installing them)?

-Wayne

gbradcsi · 10-14-2002, 09:27 PM

The silver plugs were pre gapped and i checked them they were exactly .028". but the problem i had was with either type of plug after i found the dipstick partially out.

the change of the ECU cured the problem of not starting at times.

i believe the oxygen sensor may hav ben coated with oiul and gave a false reading to the ECU.

the Bosch multi prong platinums are back in and they seem to work better on my bmw.

the car is running ok now and passed smog inspection today with no problems.

Garry

Wayne 962 · Wayne 962's Garage

Cool, although you guys have easy smog checks in Vegas compared to CA!

-Wayne

gbradcsi · 10-15-2002, 08:27 AM

Wayne,

my car would pass in CA?

1987 bmw 222, 367 miles

idle test: O2=0.3; CO% 0.19; HC =75; Dilution CO+CO2=15.20

allowable for idle and 2500RPM tests: for CO% less than 1.2; for HC [PPM] less than 220; Dilution CO+CO2[%] Greater than 6.00

2500 RPM test: O2=0.3; CO% =0.13; HC=32; CO+CO2= 15.10

they say it's cleaner than most NEW US made cars. ;-)

my other cars have similar numbers.

Jared at Pelican Parts · 10-15-2002, 09:39 AM

Garry,

Try this. Simply disconnect your battery, and let the car sit for an hour. Did you let the ECU reset itself after changing it? Disconnecting the battery and letting the car sit for one hour will reset the ECU, (I mean ONE hour, not 55 mins. It has to be one hour at least)

Also, do NOT run Platinum 4's in this car. They do not work well with the ignition system. Somewhere I remember reading that BMW actually said NOT to use them. Bosch Silbers are the way to go.

gbradcsi · 10-15-2002, 01:43 PM

Hi,

I have been using these Bosch platinums for more than three years now and the car has been very good.
i will change back to the Silber plugs and i will reconnect the original ECU and see if it works.
sounds like you know your stuff, i never realized that you could reset the ECU like this.
i opened both covers and did not see or smell anything abnormal.

the problem actually started when i did change back to the Silber plugs, because someone else prior to this problem suggested like you that the Silber plugs are highly recommended. i drove it later that evening on the highway with no problems for 16 miles to work. in the morning when i started it there was this huge cloud of blue oil smoke. it started and made it back 16 miles, but i stopped at a store close to home for two minutes and then it did not start. i found the dipstick partially out. i got it partially home, shy by about 300 yards and i pulled it home with my other car.

yesterday it passed smog with no problem. it's been running fine ever since.

Wayne 962 · Wayne 962's Garage

Crap - I hate when that happens. Pulling one car home with the other is very embarrassing.

-Wayne

Jared at Pelican Parts · 10-18-2002, 11:50 AM

It also depends on the car you are using to tow the other. One time I was driving my dad's Ford box van (brother races dirt bikes), and it broke down about a block from the house, I get back to his house, no one is there, so I end up getting my car at the time, Honda Accord to pull this 3-ton van one block back to my dad's house using a chain. Surprised the hell out of me that my little 4-pot would pull that van. It was pretty embarrassing.