323i 1996 mysterious problems - United Bimmer Community

**tnxgalaxy** · 12-07-2010, 03:38 PM

Hi folks,

I bought a 1996 323i bmw in June and I was pretty happy about it, until the recent troubles I'm having.
First, after having travelled about 150 miles on the motorway (without any problem at all), when I finally arrived in the city centre the car suddenly lost a lot of power (making some kind of loud noise when I pressed the accelerator, and it wasn't possible to go above 30mph at all).

I read some other posts on the forum suggesting the problem could come from the MAF sensor, so I gave a try with the MAF plug disconnected and I got the exact same behaviour from the car. So I thought the MAF was the cause of the pain and I replaced it with a brand new one.

After the replacement, gosh! the problem wasn't solved! When the engine was cold, it ran nearly as normal but as soon as it it warmed up (after about a minute), it wasn't possible to go over 1000rpm on the 3rd gear any more (1500 with the 1st gear) and it really felt just like if no additional petrol was injected in the cylinders when the throttle opened up.

So I started to test the sensors with a multimeter. Some of the test required the engine to be started when I tried ... The engine cranks but no ignition at all!
Impossible to start the engine anymore !

I checked the followings:
- battery's voltage is a bit low (12V) but should be ok so far
- the fuel pump buzzes when I turn the ignition. When I pince the flexible pipe at the top of the fuel pump, I can feel the pressure at the moment of turning the ignition so I would say the pump looks ok
- the fuel and air filters have been replaced recently (before the troubles started)
- the fuses are ok
- there is 11.58V on the injectors
- no fault lamp is on on the instrument panel
- the sparking plugs have all been changed in June

I have no ELM 327 at the moment but I should receive one soon, hopefully it will tell me more about what is going on.

Any clue about what the problems could be ? could they be caused by a single fault ?

Thanks for your help !

Big Evil · 12-07-2010, 05:46 PM

Vacuum leak check to start with. Your voltages seem a bit off, maybe test the battery/charging system. Also if possible, get it scanned to see if the are any pending codes that haven't set off the light yet.

**Manolito** · 12-08-2010, 08:48 AM

Not really critical to the discussion, but a 1996 323? I thought that 323s were e46s built around 2000/2001.

When you were looking at the MAF sensor, did you carefully examine the air tube from the MAF up to the throttle body? Did you look at the rubber boot on the throttle body? I am trying to square the loud noise you noticed with your power loss, and a huge air leak along that tube would be audible and would cause the symptoms you describe.

Can you describe the noise you heard? Is it still making the noise?

**tnxgalaxy** · 12-09-2010, 04:19 PM

First thanks for your replies,

Big Evil, yes indeed my battery was defective, and with the recent cold days we had over Dublin (Ireland), I think its weakness has just become more visible.
I replaced it today with a battery of a larger capacity (strangely the 100Ah bosch one was just as expensive as the 70Ah I was recommended to buy).

The ELM 327 I ordered finally arrived ! but unfortunately it seems that my car is not ODB2 compatible

(carsoft says unable to establish connection, please check the cables etc. even though the ELM is working perfectly).

I read over the web that unfortunately, if US versions of the BMWs in 1996 were all compatible with ODBII, it wasn't the case in the european countries.

Manolito, yes my car is a E36 323i of 1996. Don't know if it was sold in the US at that time, it could be the reason why you never heard of it.

Yes I carefully examined the rubber boot, it was cracked and I replaced it about 2 weeks ago. But as the car is not starting at the moment I couldn't notice any change yet (I had the jumping problem on 1st gear before which is likely to be due to the cracked rubber boot).

Concerning the loud noise, it is kinda hard to describe properly but it is like when I push the accelerator the engine sound turns loud like if air was blown into it but with too little petrol. At idle it was running perfectly but as soon as I got too far in the rpms, I had the noise and a stall in the power / rpm increase. It just feels to me like all I could control with the accelerator pedal is the amount of air to inject in the engine, and it is just like if the petrol quantity injected was only the small amount controlled by the idle control. It is just a feeling I'm not sure it is really what's happening.

Now to focus a bit of the engine starting problem, with the new battery installed the engine won't start properly either. It runs at about 1000rpm for 3 seconds with a dodgy sound and then stops (kind of plom plom plom sound).
Someone told me this could be due to a disfunction of either the camshaft sensor or of the crankshaft sensor.
What do you guys think ? Could one of these two sensors be at the origin of all the troubles the E36 is having ?

Big Evil · 12-09-2010, 11:53 PM

It's very possible that those sensors could have something to do with your problem. It's also possible that you have a fuel pump on it's way out, a clogged injector, or more than likely a clogged fuel filter. When was the filter last replaced?

**victor rametse** · 12-10-2010, 12:41 AM

guys i a also have a 323i dolphine shape (vanos engine) and it seems like as if the wiper motor is dead and from what i have seen it looks very difficult to take it out or to replace it, so is the any one who can help or is there any webside that i can go to that can show me pictures or instruction on how to take out the wiper motor please help the raining season have started in south africa please help.

**tnxgalaxy** · 12-10-2010, 02:39 AM

Testing those sensor is definitely the next thing I'll do.
Concerning the fuel pump and the fuel filter, they are both fine as described in my initial post.
Thanks for you help, I will keep you updated as soon as I know more.

victor this thread as really little to do with the problem you are having so if you want proper answers I would suggest you create a new one for it

cheers

**tnxgalaxy** · 12-14-2010, 11:24 AM

quick update, the resistance between the pins 1 and 2 of the crankshaft sensort cannot be measured like on an open circuit so it's likely the wires are sectioned. Ordered a new sensor, will keep you guys updated.

**David Mc** · 12-18-2010, 06:50 PM

My vote goes to a vacuum leak in the intake system. Think about the problem and the way your car operates - when the car is cold the DME reacts by enriching the air/fuel mixture (which will tend to mask uninvited air which enters the intake system via a vacuum leak). When the car warms up, the DME leans the air/fuel mix, which will result in an excessively lean mix, resulting in poor driveability. Admittedly crank position sensor malfunction can replicate these conditions as a bad one will often work when cold and break down as the engine warms up.

**richard66** · 12-19-2010, 12:16 AM

my 525i have some problems these days

bad engine, gas leakage

any soultion

**David Mc** · 12-19-2010, 01:13 AM

Start by reading the fault codes.

**tnxgalaxy** · 01-10-2011, 04:45 PM

SOLVED:

There was no fault code.
There was several problems, if the engine refused to start it was because the crankshaft sensor was dead.
The other problem (power problem) was because the catalytic converter was obstruated. Once it got changed the problem was fixed, it is a really nasty one because the DME is not able to detect any fault in that case.

Thanks for your help !

**scooter** · 01-10-2011, 05:00 PM

thanks for the update and kudos on solving the problems.
im sure these will help others.