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View Full Version : Help, Car keeps stalling in the rain


JimZYellow
08-27-2004, 11:49 AM
ya like the subject says, my e36 keeps stalling in the rain or after a wash. anyone know why this keeps happening?

RevShoT
08-27-2004, 11:53 AM
do u have a cold air intake?

Justin e36
08-27-2004, 11:53 AM
wet ECU. since it happens after it rains too I'll bet that your drain holes are plugged up... ECU getting wet and car won't start. Fix ASAP.. get too much water in there and it'll short out / fry your ECU.


Q: From doing a bit of research I notice that the absurdity of what happened to me on a beautiful Sunday afternoon has befallen countless others. I took my '92 BMW 325i to the car wash and within seconds it shuttered, stalled and would not restart, I had it towed to BMW and a new computer is going to be needed for what I am sure is going to be an exorbitant fee.....how could this have been avoided?"

A: Yes that has been a problem with 3 Series BMWs. Why does it happen? The drain in the cowling (thatís the grill at the base for the front windshield) is not big enough to handle the volume of water that a car wash dumps on the vehicle. BMW says the excessive water entering the cowling overwhelms the cowling drain. Overwhelming is a nice word for not having big enough drains in the cowling. You, and many other BMW owners, have found out that the computer does not like water. While youíre having your computer replaced be sure to have the new and improved drainage kit installed in the cowling. This should prevent flood water from drowning your replacement computer.

Gamite
08-27-2004, 12:24 PM
can't he just go and get the drainage kit to save his current ecu?

Justin e36
08-27-2004, 12:34 PM
he can get the newer drainage kit.. it costs $$ and is virtually identical to the current one except it has 1 more drain holes on it. I say, take out your current ECU and drill a hole in it and attach a new drain hose (part number BW-51-73-8-144-152)

clean out an debris, and put it back together. :)


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quoted from http://www.pelicanparts.com/bmw/techarticles/E36-DME-Repair/E36-DME-Repair.htm

"...pull back the insulation that is located against the rear firewall. Remove and throw away the right side plenum drain hose at this time (Figure 1). Behind the firewall material, there is a circular area pre-stamped in the firewall just above and to the right of the original drain location. You will be drilling out this hole and installing the new drain hose in this hole. BMW specifically recommends against using a hole saw here - the metal shavings are too likely to contaminate either the engine or the plenum area. Instead, start with a .375" pilot hole and use a 1/2" conduit punch. Then, use a 3/4" conduit punch and enlarge the hole to 28.2mm (1.11"). File off the edges, paint with a small bit of primer, and then reinstall the firewall insulation. Drill a corresponding hole in the installation, and install your two new drain hoses (part number BW-51-73-8-144-152), slightly angled 30 degrees towards the center of the car. That's the BMW fix described for this problem. Figure 2 shows the area where you need to drill (yellow arrow), and also points to the oil drain hose (green arrow) that should be pulled out and replaced."

http://www.pelicanparts.com/bmw/techarticles/E36-DME-Repair/pic4.jpg

Justin e36
08-27-2004, 12:38 PM
by the way, while you're at it change your other drain hoses too.

BMW has an improved style drain hose. the old ones are like a flattened straw on one end.. not much can move through at one time...

BigD
08-27-2004, 03:15 PM
Check your sparkplug wires (including the main coil lead), they're probably cracked.

Justin e36
08-27-2004, 03:22 PM
Originally posted by BigD
Check your sparkplug wires (including the main coil lead), they're probably cracked.

would water get on the sparkplug wires if the hood is closed in the rain?...

Adriano
08-27-2004, 04:19 PM
How in the hell does water get near your ECU? I thaught that the compartment it was in is completely sealed, not to mention the ECU itself is sealed. Were does the water enter the ECU compartment???

Justin e36
08-27-2004, 04:30 PM
Originally posted by Adriano
How in the hell does water get near your ECU? I thaught that the compartment it was in is completely sealed, not to mention the ECU itself is sealed. Were does the water enter the ECU compartment???

The DME compartment is located right next to the intake plenum cowl for the heating and air conditioning system. This cowl is open to the enviroment, and thus will get rain water deposited into it. There are drains at the bottom designed to drain this rainwater. However, if the volume of water is too great, or the channels become clogged with leaves or other debris, this plenum will overflow directly into the DME compartment. If enough water fills this chamber, it may also leak into the passenger side foot well, although this often goes unnoticed, as the water will leak under the passenger floor mat.

MarkD
08-27-2004, 09:19 PM
Originally posted by BigD
Check your sparkplug wires (including the main coil lead), they're probably cracked.

E36's have 6 coil packs so there is no "main coil lead".

As others mentioned, the DME is probably getting wet. You may want to open it up and spray with conformal coating.

MarkD

sonic07
08-27-2004, 11:10 PM
how about wrap the whole ECU in the plastic bag and close it up with a tie wrap or elastic band.

BigD
08-27-2004, 11:26 PM
Originally posted by Justin e36
would water get on the sparkplug wires if the hood is closed in the rain?...

It's not exactly direct water splash, but the pulverized water in the air. It doesn't take much for a high voltage lead that has cracked insulation to short onto the valve cover or whatever.

But, Mark says the M40 has individual coils so this is moot. The worst that will happen is the one cylinder will misfire.

325iSBimmer
08-28-2004, 11:42 AM
It's 99.999% certain that its your DME getting floode.
It takes like 5 min to pull it out and check it. You'll know right away cause their will be sings of water. If your DME is still fine then yes spray it with a conformal coating (like MarkD said)

if your DME is damaged don't call the dealer for a new cause you'll just cry.....$1600....
take it to your local radio shack and if they're any good they can fix the shorted out caps and such electrical pieces on the board...Thats what they did wiht mine and it was pretty screwed when i brought it in...the car wouldnt even run..
cost me like $45

MarkD
08-28-2004, 01:40 PM
Originally posted by 325iSBimmer
...take it to your local radio shack and if they're any good they can fix the shorted out caps and such electrical pieces on the board...Thats what they did wiht mine and it was pretty screwed when i brought it in...the car wouldnt even run..
cost me like $45

If you took it to RS and they fixed it, you are very lucky. I don't know of any RS stores that actually repair anything, you probably just met up with some guy that was good at soldering.

In almost all cases, you just have to clean off the greyish coloured deposits you will see on the PCB and spray on the conformal coating. It's not likely that any components will need replacing.

MarkD

325isRED
08-28-2004, 11:42 PM
This must be a common problem...
A few weeks ago i bought a 325is, I owned it for 2 days when I took it for its first car wash, we had to push it out of dennys because the car wouldnt start, and actually hydro-locked after only a little bit of cranking... I took it to a mechanic in clarkson and he told me the computer was flooded, shorted, and in turn kept the injectors wide open which caused the flooding... I found a refurbished computer for 300 bux(thaught it was a good deal since i called bmw and they said about 2000). He also charged me 500 bux for labor and other things. A friend of mine's pops is in law and he sudgests going after bmw for my expences, anyone ever done this or heard of it being done? I am 18 years old and am now in debt (spent every penny i had on the car) hope this is not a begging of bad things from my bimmer...

aswell, some asshole stole my fog lights while it sat overnight at mavis and central (they where brand new)...

djcontra
08-29-2004, 09:55 PM
didn't have time to read the whole thread, but on my car this is a major problem/headache for me but I've learned to live with it. The rear spark plug socket always fills up with water whenever it rains fairly hard causing me to lose ignition and the car will eventually stumble to a stall. If you haven't checked for water in your coils or spark plug area, then do so right away. *th-up*

(eventually I'll put my engine cover back on which will resolve this issue, but for now I'm too lazy hehe)