XSeries-forum

Believe it or not the car drove in to be MOT'ed three years ago, and the guides went whilst having the emissions checked. I had only ever driven it 1/2 a mile to the MOT station, prior to last week.

Don't think my mechanic wanted to do the job, but he agreed to it, and we agreed a capped fixed price. The bottom book value of the car at that time.  The previous owner had reported a mis-fire which turned out to be the VANOS on bank one which was spitting oil, witnessed that myself with the engine out when he manually rotated the crank.

Found an excellent post on bimmerforums. Poor dude with a 2003 540 has had code 33 for 6 weeks now, having changed guides and chains, engine covers off half a dozen times fine tuning the timing, bank one. Seems quite a specialized procedure. Will share the link, really useful wisdom in it.

For anyone with a code 33, recommended reading.
https://www.bimmerforums.com/forum/show ... ment/page5

Yes, very interesting, is the trigger wheel the route your going to take. I agree the air leak after MAF for fuel trim faults but didn't you say you had checked for air leaks, hence looking at the o2 sensors

I asked guru JimLev that question, the fuel trim issues are most likely causing the misfire, which is being caused by the vacuum leak. I thought it would have been the VANOS code, but he says not. The timing has to be way out before that causes mis-fires.

So for code 140, I need to check that the electric thermostat is connected properly, apparently coolant can get into it. And check the resistance, 11-12 ohms apparently.

Secondly check for intake air leaks between MAF and intake, which I haven't checked yet. Looking at YouTube videos, that could be quite an extensive search / strip-down... but throttle body gasket is a contender and relatively easy to repair. Thing is my idle is fine, so not sure if vacuum leaks will show up easily. My misfire is at mid-range revs under load. Question is do I use brake cleaner to identify my leak? Don't have access to smoke equipment.

Then back to the garage and get him to tweek the trigger wheel on bank one a few degrees CCW/CW and see if that clears fault 33... Think I read somewhere that if code 33 is active that VANOS is then electrically disabled at the solenoid, until fault gets cleared.

Found another post regarding fuel trim errors..

Recommended way forward...

1) start by checking manifold gaskets.
2) replace O2 sensors. Henry

As the engine has been stripped and rebuilt an air leak is possible, never used brake cleaner to check I've always used carb cleaner but if your idle is good it must be a small leak. Still favour o2 sensor as a misfire caused by plugs or coil pack normally shows up with it's own fault code. The 140 code is the thermostat, I have that permanent as I converted to a different thermostat to lower running temperature, I have a resistor to bluff the DME, must get it fitted. Back to misfire, not convinced you have one, may sound like one because timing won't allow the engine to rev beyond 3 to 4k so there must be some sort of hesitation reluctance to go beyond that point, you could be wasting your time chasing a problem that isn't there,

Ok, I hear what you're saying..

We know what I'm doing this weekend... will get carb cleaner from Halfords on my way home tomorrow.

Will cost up and order some O2 sensors...

I'd hate you to spend money, well to much money on my advice, the carb cleaner fair enough but surely you should get the indie to try the trigger wheel first, I assume any work he does now to get it right is part of your agreed price and if that works he should knock something off the agreed price as he will have learned something invaluable to him

I'll check the thermostat and get the carb cleaner to check for leaks. Will try and move things forward a bit. Was planning to take the 330 off the road for winter. Think I'll keep it on the road for November at least until I get some of these probs ironed out.

Think you talk good sense...

More reading last night found this. By Ron Stultz on his shared knowledge website "What Can Go Wrong - CEL:

Obviously from the "normal operation" description above, a lot of different components are involved in fuel management and thus emissions and the dreaded CEL. Ok, so you have a CEL, what do you do? Most people just take the car to a shop and that is the end of it, but if you are so inclined to try to save some money and like doing things yourself, CEL is not beyond being diagnosed by an owner. But you have to have a special tool and that is what is known as a scanner, which is connected to the OBCII interface defined above.

There are 5 types of scanners in the market: (1) Very simply, reset devices, that allow an owner to reset the CEL and perhaps retrieve some stored DTC's. Beyond the OBCII interface and what can be examined using it, BMW cars also have other special to BMW DTC's that simple scanners will not recognize (2) A more sophisticated handheld scanner that that looks at OBCII data and perhaps can display some information in real time. Example of real time display is where you want to look at the voltages of the pre and post CAT O2 sensors. This type scanner is available for free use at most AutoZone retail parts stores but do not expect to borrow it and immediately make heads or tails out of what is displayed. (3) More sophisticated personal computer-based hardware and software. With this type of scanner and add-on software specific to BMW, an owner can see most DTC's and look at various engine management data in real time. For example, one can see MAF sensor readings, the intake manifold temperature reading, etc. etc. (4) Independent BMW repair shops scanners and (5) Dealer scanners, which are very expensive and can be used to read all DTC's as well as "code" various replacement components to a car.

Ok, so you get a scanner of some type. Obviously the first thing to look at is the pre and post CAT 02 sensor voltages. As described above, if the front sensor is not changing while the engine is running or is very sluggish in changing from rich to lean or lean to rich, it is probably defective and needs to be replaced. If the post CAT O2 sensor does not have a steady voltage, this may or may not mean you have a bad catalytic converter.

Things that can totally screw with the engine management system include: intake manifold leaks; exhaust leaks; vacuum leaks, a MAF that is misreporting intake air mass; a defective intake temperature sensor, etc. etc. A scanner that shows DTC's will help you identify issues that might be causing your CEL beyond it simply being the pre CAT O2 sensor or a bad CAT."

So up to now I've been using my mechanic's scanner to get the codes, but I can see that a scanner is a necessary investment with one of these machines. I see how crucial the O2 sensors are from the above, but also intake manifolds, vacuum leaks etc.

So I will be researching what is the most cost effective research tool to invest in... Was considering cheap and cheerful to get me started, but not sure now.

MVDIAG? £62, save me the cost of an O2 sensor?
BMW Scanner 1.4.0?
Carsoft
Autologic
INPA
DIS / GT1
NCS Expert
WINKIP (not recommended........Very easy to brick your car apparently)
Progmann

Any experience of these?

Like the look of this scanner cable ....

http://www.ebay.co.uk/itm/BMW-DIAGNOSTI ... SwH09ZIMjC

I just bought one of those, bought one years and years ago but didn't have the computer skills to load it up but now they advertised that it's loads automatically and a monkey can do it. I can report that I am at least on an equal par with a monkey as I managed to load it. Haven't actually used it yet as I've been up north but will try it sometime soon. I have an excellent Foxwell NT644 Pro which picks up codes many other scanners don't, does live data but doesn't allow to code hence the INPA,