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Old 02-06-2004, 09:18 AM   #1 (permalink)
Join Date: Feb 2004
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makdolby is an unknown quantity at this point
Help me please?

A little history...

...I bought a 1992 (J) reg, 325i non-VANOS M50 BMW about 5 months ago. Shortly after buying it privately it started to misfire occasionally (mainly at low revs. At high revs it was running sweet!). I took it to one of my local independent BMW specialists who gave it a full safety check at the cost of 40-bargain considering the AA wanted 200! They also listed all the things that needed to be done on it including a cracked prop-shaft, new rear suspension...ect ect with an estimated bill of approximately 1,500 including a TypeII inspection and labour of course!

I then took the car to another independant BMW mechanic who put the car up on the ramp and went through the list given to me previously. Only about 4 out of the list of 15 items needed to be replaced (this wasn't the suspension or the prop shaft by the way) and including a TypeII service+labour was changed 460. The first time I took the car to him there was a sign of an idle problem a surging or hunting. My mechanic said its more than likely to be the Idle Control Valve, so after replacing the Bosch part (850 the New Idle Problem disappeared - incidentally, idle problems are common on the E36. although the Idle control Valve is a good place to start, its not the only place as you will learn later. I later realised that the idle control Valve gets clogged up and the flap/motor ceases from the excess carbon due to a rich fuel system. This can be cleaned in a small amount of petrol with a toothbrush, thus saving 85!)

Although I told my mechanic about the occasional misfire, he said there were no error codes present and that when he took it for a test drive there was no misfire - fantastic news for me. I guess that replacing the spark plugs and filters etc during the type II inspection had got rid of my problem...Hmmmmm?

A few weeks later after beautiful motoring with a 192BHP 2.5 litre rear wheel car, albeit a little hungry on petrol (approx. 300miles on a full tank of fuel = 40 NOTE: you still have about 40-50 miles/80km after the fuel light goes on - I'm new to the world of Bimmers) It started misfiring again. I took it back to the garage, but he could find nothing wrong with it...I lived with this misfire for a few months, as it really wasn't a huge problem and being without a motor for any length of time is a real pain.

After a while, the misfire still there, I heard a constant clicking or tick tick ticking sound coming from the engine. On inspection, I found it to be the PCV [Positive Crankshaft Ventilation or Purge Valve as its commonly known]. This valve was opening and closing rapidly causing the clicking. I unplugged the valve and the noise stopped. Re-plugging the valve brought back the clicking. I told my mechanic about this and he said that the valve wasn't causing a problem. Meanwhile, the top of the Carbon Filter [a cylindrical component about 3inches in diameter by 5 inches in height] had broken off. There are two pipes coming off the top and a larger pipe coming from the bottom. Its bolted onto the front RHS of the engine bay, near the Purge Valve. I tried to glue the plastic tube back on but ended up tapping a small copper tube into the Carbon filter. The pipe could then be fixed back on.

Still, the misfire remained, but also there was a complete lack of power, once again intermittent. Whilst driving, the car would suddenly cut out, drop revs, and then suddenly pick up again. This, at first was occasional, but the problem did get worse until the car would completely cut out and would not re-start. After a while, you could then start the car and everything would be ok. I noticed that it would happen worse under load [i.e. in gear. If I put the clutch in and revved the car, it wouldn't cut out, or I would get revs back again. By taking the clutch out, it would then misfire, stall and cut out.

A pattern did emerge. It would be worse when the car had been parked on a flat surface [we live on a hill, so usually ok] and when it has been raining!

The next problem I had was major! One day in January, the car was working, the next morning the car was dead - completely dead. No central locking, no lights etc. I measured the battery and it was 1Vdc. I then called the AA Breakdown who came and tried to jump start me. There was nothing...The engine sounded as though it had ceased? On the turn of the ignition key, the car didn't even turn over? The AA then took off the Coils & plugs to find petrol floating in all 6 of the cylinders. It didn't look good. He then asked me to turn the ignition again and petrol shot out about 8ft across the road!

He then towed me to my BMW garage who tried to get fault codes from the ECU. He told me that he could get no reading from the ECU and thus towed it to the BMW Main Dealers. I then dealt direct with the engineer from the BMW main dealer.

They told me that they could get no compression from the engine. They poured a small cup of oil into the head to rid of any petrol [I have no idea if this is a good thing to do...? I would have thought that leaving it to evaporate or manually siphoning out the petrol would have been a better route]. After this they said they could manually get compression back into the engine but there was no spark and still no ECU output so first things first a new ECU! Now, BMW main dealer wanted to charge me 700+ for a new ECU - Bearing in mind its a 12 year old car]. I said that I would source one elsewhere and picked up one for 180 from a UK BMW breakers with the understanding that if it wasn't the correct part, they would only charge me 10 and refund me in full - this was guaranteed for 6 months - great! The new [second hand] ECU seemed to do the trick as there was now a spark and engine management back. The main dealer reset the fault codes and took it for a test drive. They said that there was no misfire, but there was now erratic idling when the car had warmed up. When the car was cold, it would start, run smooth until the temperature had increased. The car idle would then hunt between 400-1200 rpm. The fault code from ECU was 1215 - Air Mass / Volume Sensor. I then sourced an Air Mass Meter [MAF - Mass Air Flow] and put this on. The fault and code was still present. BMW Main Dealer then checked many many things such at the Lamda Probe [aka O2 sensor], which was ok. The Idle Control Valve was replaced again; there was an engine breather hose off from the air intake manifold. They then suggested that they change the 6 coils. At present, I had 2 Bremi coils and 4 older Zundspole coils. I have read up a lot on these problems and people seem to agree that the old Zundspole coils were very bad indeed. There was a problem with the Pre-1995 BMW coils. They were very bad at cracking and causing misfire and erratic idle. The coils should be replaced with Bremi coils [28.50+VAT from Europspec / BMW wanted 52+VAT!]. The coils can be tested in the following way:

a) Measure the primary windings. They should be between 0.4-0.8ohms. The secondary windings should be >20MOhms [O/C]


B) Pull each coil in turn. A loss of power/an idle drop should be observed. If pulling the coil makes no difference then that coil is faulty.

But, once BMW had replaced the coils, they were still not guaranteeing the problem would be resolved so 366 is a lot of cash to spend if its not the problem, where as Europarts identical coils would cost me 200! BMW say that all their parts are fully tested and guaranteed and they are not allowed to put non-BMW parts in the car...Surely they should have spare parts available to fault find without clocking up huge bills to the customer every time they think a part maybe faulty? At 88 per hour, you would think youre getting quality of service and access to the largest BMW database of fault finding engineers and expertise...Apparently not!

Anyway, after being very frustrated after BMW were suggesting that they were unable to fix my car without costing a fortune [using their fault finding technique described above] I was charged 160.00 for their time to fit the ECU and fault find to a point and took the car, still with Idle problems.

On driving away I found that the Instrument panel was showing "pppppp" where the mileage should be, and that the Fuel & Temp gauge was not working. Also the Average MPG (beneath the RPM dial) and the rev counter itself were also not working. However, the instrument lights and the backlight were ok, including the MPH dial? On approaching BMW dealer, they said that the car was like this when it was brought to them (initially dead!). They said that a common problem of jump starting the BMWs is the Instrument panel blowing. This is due to a surge or spike whilst disconnecting the Negative, and then positive terminals off the battery. It does say in the BMW Owners handbook, than once the car has been jump started, switch on the headlights, fan and rear heater before removing the terminals from the jump starter...Im not sure if this is common knowledge so be warned. I sourced a second hand instrument panel to see if this was working. There are 2 various 1992 325i instrument panels available: One with a white plastic rear and the other Blue. The difference seems to be minimal, with a few different dials. I took the chance to try the Blue one in my car (original one was white) and the mileage came back (although it was 100,000 miles and not 133,000 miles. I guess this is either stored locally in the instrument panel, or in the ECU? The rev dial along with the fuel and temp were working immediately. I am planning to merge the two together anyone done this before? Else I pay 150 for a second hand one.

Now back to the main fault...Looking at the paperwork I received from the main dealer, this is what they had done:

Checked for non start, carryout electrical test of fuel system, all functioning ok. Checked fuel pressure, ok. Checked crank sensor & DME relays, ok. Internal fault in DME as not communicating with DIS. Fitted second hand control unit, car starts but runs poorly when hot.

Notes: Replaced split air hose under inlet manifold. Fault showing as air mass meter. Tried second hand air mass meter, no better. Checked spark plugs and compression all ok. Removed and checked Lamda probe (O2 sensor) and all ok. Car shows as over fuelling when warm, causes cutting out

I then took the car back to my local independent BMW mechanic and worked on it myself after looking on the internet for many idle problems. I had a few things to try, even though I didnt really know anything about cars before. I took of the air intake manifold (a real pain to reach the last nut on the block closest to the windscreen but taking out the rubber plate just below the wiring loom under the windscreen helps). Also the brace nut closest to windscreen is a little difficult, but loosening the dip stick helped. I found a few more pipes perished and so replaced (so much for that type II inspection!). Still the car was hunting or erratic idling. I did notice that when I quickly revved the car from under the bonnet, I could hear a brief sucking noise coming from around the air intake manifold. I have checked for further leaks and seals but cannot find anything Does anyone know what this sucking noise is? If you hold the U bend pipe going to the Idle Control Valve whilst revving the throttle, the pipe collapses a little, but doesnt appear to be a problem?

By now I was getting desperate so I turned to the internet and found a fantastic web site: I typed in Idle and found 358 results, each with similar problems. It took about 4 hours to sieve through the results, but wealth of information Thanks guys. I made a note of all the things I could try. I read up on how the engine system works and started deducing my own fault fining technique. I decided that the coils were a MUST as the 4 old Zundspole coils were a culprit of almost every problem I was having: Misfire, Idle problems, cutting out at any rev and worse when it was damp! After replacing the coils with 4 second hand Bremi coils my mechanic had available, he said that there was no longer a misfire or engine stalling, but the idle problem was still there. I then checked the MAF (Air Mass Meter) connections as the ECU was still giving the fault code: 1215. I found the following resistance measurements from the male pins on the MAF. Pin 4 was ground so all resistances was reference to Pin4@temp=10degreeC.

Pin4-1: 15.6k ohms
Pin4-2: 21.2k ohms
Pin4-3: Open Circuit
Pin4-5: Short Circuit
Pin4-6: 3 ohms

From these measurements I assume that the coil was 3 ohms and therefore was ok. I then found that the engine ran better, well didnt hunt whilst the plug was off. When I put the plug back on, I got the idle problem back. I then looked at the plug itself and found the female sockets were oxidized! After cleaning them and re-connecting the plug the idle problem had disappeared!

This was last night, so I took it for a long test drive in rush hour traffic and a good run out on the motorway. The car was running better than ever! No misfiring at all. Very smooth transition between gears. The idle speed was constant and was purring beautifully! There was no backfiring and engine stalling or cutting out. After test driving for while, I then listened under the bonnet and had a good look around. The engine was still making that sucking noise when I manually revved the engine. There was no smell or smoke coming from the car engine now, although I do suspect that a pipe or gasket in the water system has a split as there was lots of smoke/steam previously (any ideas?). I was very suspicious of the Purge Valve feeding the PCV as this is recommended that its changed every 30,000 miles. I remembered back to the tick tick ticking sound a few months back and decided to feel it. It was buzzing/humming. Almost as though the switch or control was stuck, but taking of off and blowing it proved the valve was working one way and shutting off the other way...Any other reason to swap this out?

I tried the car this morning after a night of heavy rain, the car parked on a hill with the bonnet facing upwards. The card started first time and after 20 minuets of driving this morning, again no misfire, no hunting, just perfect motoring.

Please do comment and email me with any thing you have found interesting or any further solutions to my problem. I hope this is of some use to some of you...I learn a few valuable lessons along the way:
1. I would never buy a first design car again. The 1992 was the first of the E36 BMWs. I guess by the time they reached 1998 (last model, they had got it right so this model would be the best model/year to go for.
2. Never trust a Main Dealer. I am sure there are main dealers that are worth 88 an hour, but from the experience I have received and from the information I have read, many faults that require a good level of real engineering have gone a miss with main dealers and have ended up being resolved by the car owner If you want a job done properly Do it yourself!
3. Find and treasure any BMW breakers or reliable mechanic as they will always have time and interest to help you out (and will be considerably cheaper)
4. Finally, I am unsure if I will ever buy a BMW again! Knowing what I know now, the whole structure of the BMWs form the build to the running to the maintenance doesnt seem to work for my (well, unless you have lots of spare cash to throw away!). It will take a lot of convincing to change my perception. A real shame as they are lovely cars to drive.

Take care and happy motoring!

Best Regards
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Old 03-14-2006, 11:18 AM   #2 (permalink)
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you mention the old sign, are you in London? if so can point you to someone who knows Beemers inside out (ex-BMW tech got his own unit now) and he's one of the good guys, not a rip off.
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Old 03-14-2006, 02:44 PM   #3 (permalink)
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Originally Posted by makdolby

A little history...

<img src='' border='0' alt='user posted image' />
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Old 03-15-2006, 02:37 PM   #4 (permalink)
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interesting story.. i'll be sure to double check my MAF connector (although no idling problems currently, always better to keep one step ahead)
Complete mod list and pics:

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Old 01-15-2008, 01:50 PM   #5 (permalink)
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hi every one i have a 323i 2.5 97 preg bm,,been getting the same probs but when it happens it will not rev above 1000 rpm,,i am lucky enough to own a snap on code reader(need some more lessons with it lol) any way it came up with these three codes

08 air mass sensor

212 vanos - mechanical fault

83 crankshaft position sensor

in that order and again when cleared,,do they all need replacing? as the bloke i brought the car of said it had a new air flow meter fitted already any help would great thanks Darren
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Old 01-15-2008, 02:29 PM   #6 (permalink)
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I had a similar problem and it was a simple fix. check out the rubber spark plug boots on the coil mine was cracked and created many problems. Changed the coil pack and boot and mis fire was gone
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Old 01-15-2008, 02:33 PM   #7 (permalink)
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k thanks for response, ill have a look in the morning
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Old 01-20-2008, 01:22 PM   #8 (permalink)
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ok crank shaft sensor was the starting problem and rev problem,, i replaced air mass meter but still comes up as fault (strange) ,,, and vanos fault still there,,is this the selanoid at fault?? and now the car has a flat spot at half throttle apart from flat spot it runs great
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Old 01-20-2008, 03:40 PM   #9 (permalink)
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sounds like a throttle position sensor to me... check it with a volt meter and see if the reading is smooth when you open it and close it...
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Old 12-22-2008, 05:23 PM   #10 (permalink)
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Change Ur Spark Pugs. New Petrol Pump! New Dme Relays Fix Idel Prob! Fuel Relay Car Will Run Mint! Wen U Done All This Discontcet The Battery For 5 Mins To Restart Ecu! Then Go For A 5 To 8 Mile Drive So It Can Find Its Feet! U Will Find Car Will Be Bang On The Money
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Old 12-22-2008, 05:25 PM   #11 (permalink)
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Goin Bed!!! Ha Ha Ha Do As I Said U Find Car Will Be Fine! Long Live The 318is!
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Old 02-05-2012, 07:52 AM   #12 (permalink)
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Arrow Old Rides = Master Class in Troubleshooting

8 years later and this post is as valuable as ever as I take another plunge into the engine bay of my 1992 325i. Here's the takeaway: in older vehicles connector oxidation can lead to unpredictable and costly troubleshooting. Ironic since the fix can be essentially free and as fast as pulling a connector, inspecting it, and treating it with Cramolin or DeoxIT (*CAIG Labs).

The other gotcha is age-related detioration of polymers, namely rubbers and plastics. Brittle insulation can crack and flake off wires (and coil potting) causing short circuits, and rubber eventually cracks where it can compromise vacuum and similar lines and ducts such as the air intake bellows that feeds air to the MAF. Failures in these areas usually provide intermittent and misleading diagnostic information. Best practice is to include in the inspection phase of your troubleshooting sequence.
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Old 02-05-2012, 07:57 AM   #13 (permalink)
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Thank you for the scientific explanation - Gonna get my mortar 'n pestle out
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