[FieldingMellish]

Following on from the 'All I Hear' thread...

http://www.e90post.com/forums/showth...highlight=hear

...I still haven't seen any description of what symptoms occur when one or more injectors and/or coils fail on the 6 cylinder petrol engines. If I have a warning light, say, and an injector has failed, how wil lmy car behave before I take it into BMW?

I guess I'm basically asking: will the symptoms be as debilitating as the 'limp mode' and cutting out suffered by the 4 cylinder petrols?

[Pyth_UK]

Originally Posted by FieldingMellish

Following on from the 'All I Hear' thread...

http://www.e90post.com/forums/showth...highlight=hear

...I still haven't seen any description of what symptoms occur when one or more injectors and/or coils fail on the 6 cylinder petrol engines. If I have a warning light, say, and an injector has failed, how wil lmy car behave before I take it into BMW?

I guess I'm basically asking: will the symptoms be as debilitating as the 'limp mode' and cutting out suffered by the 4 cylinder petrols?

Hi FM,

There are a variety of different faults which are possible with the named different components. Let me take your example of one injector failing....

Your engine would run on 5 cylinders as the engine control unit would turn off fuel for that cylinder (but continue to spark). NB - Some faults need to be seen to happen more than once for the light to be lit constantly.

Now the symptoms would be similar to that of a 4 cylinder engine with a failed injector..... but 6 cylinders minus 1 is going to run better/smoother/have more remaining power than an engine which is 4 cylinders minus 1.

I would imagine that when people have a 4 cylinder engine with a misfire/cylinder down they are not accounting for the 25% minimum power loss with their driving style and therefore it is easier to stall.

Hope that makes sense.

[ALF_E90]

I have considerable recent experience of driving with failed or failing coils and injectors... For me it has always been driveable but you would not fail to notice. The symptoms I have had have ranged from clearly running on 5 cylinders all the time (heavy vibration and significantly reduced power), which happened straight away the first time a coil failed, to a gentler misfire that almost seems to go away under light loads but comes back badly when you open the throttle more. Sometimes it has seemed a coil is on the way out but fighting for life when a misfire starts then goes away - indeed with it happening so often when I was a long way from home and had no choice but to drive the car, I learned to either stop and do a full re-start (key out) or just back off and drive incredibly gently when it first struck, often this makes it temporarily go away.

One "good" thing is that the engine warning light has always lit up when the misfire has struck, even gently, so the ECU does always seem to know there is a problem. When the turbo diverter valve went in my A4 2.0T there were no warning lights or codes in the computer, just a clear sense there was muchy reduced boost.

Assuming your question is related to considering buying one and wanting to see if it has this problem, it should be obvious - take it for a decent test drive and give it some heavy throttle loadings - you don't need to thrash it, most of the time with me it comes on when you open the throttle a fair bit at lowish revs in a high gear, like when a slower car clears out of the way on the motorway and you squeeze the throttle enough to resume cruising speed but not enough to make the box shift down.

Presumably if 2 coils went at once then you would be screwed!

[FieldingMellish]

Originally Posted by ALF_E90

I have considerable recent experience of driving with failed or failing coils and injectors... For me it has always been driveable but you would not fail to notice. The symptoms I have had have ranged from clearly running on 5 cylinders all the time (heavy vibration and significantly reduced power), which happened straight away the first time a coil failed, to a gentler misfire that almost seems to go away under light loads but comes back badly when you open the throttle more. Sometimes it has seemed a coil is on the way out but fighting for life when a misfire starts then goes away - indeed with it happening so often when I was a long way from home and had no choice but to drive the car, I learned to either stop and do a full re-start (key out) or just back off and drive incredibly gently when it first struck, often this makes it temporarily go away.

One "good" thing is that the engine warning light has always lit up when the misfire has struck, even gently, so the ECU does always seem to know there is a problem. When the turbo diverter valve went in my A4 2.0T there were no warning lights or codes in the computer, just a clear sense there was muchy reduced boost.

Assuming your question is related to considering buying one and wanting to see if it has this problem, it should be obvious - take it for a decent test drive and give it some heavy throttle loadings - you don't need to thrash it, most of the time with me it comes on when you open the throttle a fair bit at lowish revs in a high gear, like when a slower car clears out of the way on the motorway and you squeeze the throttle enough to resume cruising speed but not enough to make the box shift down.

Presumably if 2 coils went at once then you would be screwed!

Thanks very much for that, Alf.

Yes, as you rightly surmise, I am about to buy a 330i, and am wondering if I will suffer these problems. As you say, at least the warning lights do come on when the problems occur - this was certainly *not* always the case with the 4 cylinder petrol problems, often these would occur with no warning light at all.

One line of thinking I've been pursuing is of course to try finding a 330i which is late 2007 or early 2008 and which still has the N52 engine in it. Failing that, I will be asking the dealer to confirm for me, in writing, whether the car I'm considering purchasing has ever had any of these problems.

I'll take your advice re. teh test drive, but of course I have no way of telling whether I'll have coil/injector problems somewhere down the line after purchase. I'll have an AUC warranty for the first 12 months at least, so hopefully any problems that are waiting to happen will happen in that first year.

But do I recall from other threads that it's possible to have all 6 injectors replaced and then have some of those replacement injectors fail again?

[ALF_E90]

It seems it is the coil packs failing initially - my garage has been open about that - but sometimes when they fail they seem to take some injectors with them. Then it looks like sometimes when they change the one injector that is showing up as the issue, the issue is still there and they have permission to change all 6 under warranty. That seems to have happened to a few people on here. If you have no warranty, I assume that gets expensive...

I have my car back now but it still has two original coils - they are on backorder so they are not allowed to change all 6 (or all of the non-original ones) after repeated failures under warranty as they sometimes do with injectors. I'll let you know if any future coil pack failures also break my nice new injectors

Since these problems are ignition (and possible heat) related I'm definitely using Super all the time again now, as I used to with the Alfa GTA (then because I got the money back in better economy).

[Pyth_UK]

It amazes me reading some of the posts on this site, the extent to which some people make assumptions regarding the diagnosis (and replacement of parts) of 4 and 6 cylinder misfire issues. That is not a dig at you ALF, but there is clearly a large amount of misunderstanding on the subject among many here.

I would have thought FM, given the age of the vehicle you are looking at that any problems it may have had would have been resolved by now. If it's a dealer buy, ask if they will let you see the history.

[E92westy]

Originally Posted by Pyth_UK

...... there is clearly a large amount of misunderstanding on the subject among many here.....

Can you enlighten us then, please?
I'm genuinely interested what these 'misunderstandings' are how the assumptions are incorrect, bearing in mind, most people are going on what they've been told by the dealer...
Thanks.

[Pyth_UK]

Originally Posted by E92westy

Can you enlighten us then, please?
I'm genuinely interested what these 'misunderstandings' are how the assumptions are incorrect, bearing in mind, most people are going on what they've been told by the dealer...
Thanks.

Hi Westy,

Would be happy to offer some advice. I just find some comments offensive and to be honest so far from the mark/actual truth. There are strict procedures for diagnosing all faults on BMW's including misfires etc.

The coil problem sadly has been around too long, for all makes to be fair. Audi/Vauxhall/Ford also to name a few. They could be better, I'll agree with that.

Most models will not have any issues. Anybody who has had the software updated and has already had injectors fitted should not experience any further injector problems. That is not to say people with originals need them changed at all. The earlier injectors were run too close to their limit (in the name of performance and efficiency) which in isolated cases caused issues. One example would be a distorted spray pattern which would then eat in the plug. A damaged plug could then in turn stress the coil.

BMW has tweeked the software to obtain the best possible reliable settings (quite some time ago now). There will be thousands of cars which have left the factory with this later software. Basically, there is one test which is carried out on a car with this complaint. This test, depending on many factors can offer many different instructions on carrying out the repair. This is why you will hear people who have had 4 injectors/plugs/coils and others who have only had 1 plug and 1 coil.

The coils sadly as with many makes/models can fail at any time. This is not a new thing.

Below are some things I've read here, I find it disturbing that it is possible people really feel like this.........

"The sad thing is, the dealer will most likely fuck about with software updates, pressure switch changes and after the third visit and new pump, even though they must had got through a million of the things."

"Replacing everything across all cylinders will likely "fix" any misfire related issue. But it's the lazy way out (no diagnosis of what is actually wrong) and a good way to get a lot of money out of customers/warranty providers.

Regarding the programming, I think injectors are coded components so there will be an element of "programming" involved.

This kind of lazy workmanship/fault fixing is pushing up aftermarket warranty costs and pushing people towards having a car that is always in OEM warranty (which perversely just makes more money for the manufacturers anyway)."

[pjs]

Mine was off the road on 4 occasions over approx 7 months (dec 09 to april 10) while the dealer tried various fixes of replacing 1 or two coils, and/or 1 or 2 injectors etc. Whatever strict procedure was in place didnt exactly do the trick for me.

Only on the 5th occasion, when they replaced all 6 injectors/coils/plugs did the problem go away, done 22k miles since this fix with no further problems other than a new HPFP and this weeks incident.

[E92westy]

Originally Posted by Pyth_UK

Hi Westy,

Would be happy to offer some advice. I just find some comments offensive and to be honest so far from the mark/actual truth. There are strict procedures for diagnosing all faults on BMW's including misfires etc.

The coil problem sadly has been around too long, for all makes to be fair. Audi/Vauxhall/Ford also to name a few. They could be better, I'll agree with that.

Most models will not have any issues. Anybody who has had the software updated and has already had injectors fitted should not experience any further injector problems. That is not to say people with originals need them changed at all. The earlier injectors were run too close to their limit (in the name of performance and efficiency) which in isolated cases caused issues. One example would be a distorted spray pattern which would then eat in the plug. A damaged plug could then in turn stress the coil.

BMW has tweeked the software to obtain the best possible reliable settings (quite some time ago now). There will be thousands of cars which have left the factory with this later software. Basically, there is one test which is carried out on a car with this complaint. This test, depending on many factors can offer many different instructions on carrying out the repair. This is why you will hear people who have had 4 injectors/plugs/coils and others who have only had 1 plug and 1 coil.

The coils sadly as with many makes/models can fail at any time. This is not a new thing.

Below are some things I've read here, I find it disturbing that it is possible people really feel like this.........

"The sad thing is, the dealer will most likely fuck about with software updates, pressure switch changes and after the third visit and new pump, even though they must had got through a million of the things."

"Replacing everything across all cylinders will likely "fix" any misfire related issue. But it's the lazy way out (no diagnosis of what is actually wrong) and a good way to get a lot of money out of customers/warranty providers.

Regarding the programming, I think injectors are coded components so there will be an element of "programming" involved.

This kind of lazy workmanship/fault fixing is pushing up aftermarket warranty costs and pushing people towards having a car that is always in OEM warranty (which perversely just makes more money for the manufacturers anyway)."

Thanks very much for that info, Pyth.
That has confirmed to me that the issues I had with my now long gone (thank
God) 320i were essentially software related (as I was informed via a PM from a BMW employee on another forum to me), leading to mechanical issues.
I know that techs have to work through very prescribed procedures under BMW warranty rules in order to be able to change parts under said warranty, but as a consumer, this can be very frustrating entailing multiple visits to the dealer with essentially the 'same' problem.
This frustration often leads to 'venting' on the internet,as you've obviously seen.

The line I've highlighted in bold above is also most interesting.

I had all injectors / coils / plugs replaced plus a software update and the car still didn't feel right.
There's also posts on here of 330i / 320i multiple injector / coil replacements.
Would you put this down to simply component failure (which does happen, I agree) or are these software updates a bit of a 'fudge' for older cars, with newer ones being sorted properly in the factory?

(I'm guessing your inside the network, judging by your knowledge or am I completely wrong.... )

[FieldingMellish]

Originally Posted by Pyth_UK

Hi Westy,

Would be happy to offer some advice. I just find some comments offensive and to be honest so far from the mark/actual truth. There are strict procedures for diagnosing all faults on BMW's including misfires etc.

I take it from this that you are a BMW technician or engineer? I really appreciate your input, but, in the case of the 4 cylinder petrols, there is nothing to dispute: those engines have fundamental problems which BMW routinely deny exist, and which cannot be solved by replacing sensors, updating software, etc.

I appreciate your inupt, and certainly nobody wants to blame you, but it seems to me (and a lot of others on this forum) that BMW's "strict procedures" involve working their way up through a hierarchy of possible fixes, starting at the cheapest. And by the cheapest I mean their old favourite, i.e. telling the customer that the problem odes not exist.

I had a practically brand new, 57 plate 318i, and as well as suffering intermittent 'limp mode', every now and then it just broke down completely, usually while I was travelling at speed down a narrow B road with a line of following traffic on my tail. What would often happen was, you would feel a little 'blip' where it seemed as though the engine had cut out for a split second then come back on. This usually heralded an actual total cut-out which would occur somewhere between 30 seconds and 3 minutes later.

The dealer went through what felt like a routine cycle with me:

1. First they told me they'd fixed the problem. This stage was iterated a number of times, while they replaced sensors, updates software, etc.

2. Next they told me they *would* fix the problem, and would not rest until they had done so.

3. Then they told me they couldn't find the problem.

4. Then they suggested the problem might be "a driver issue".

5. Finally they told me there was no problem, and could I please fuck off.

Now, having spent well over £20,000 on a car which basically did not work and which was a death trap, to be told that the problem did not exist or might be "a driver issue", now *that* is offensive!

For BMW to perpetuate this attitude across who know how many thousands of dodgy 4 cylinder cars, that is way beyond 'offensive'.

[ALF_E90]

Originally Posted by Pyth_UK

It amazes me reading some of the posts on this site, the extent to which some people make assumptions regarding the diagnosis (and replacement of parts) of 4 and 6 cylinder misfire issues. That is not a dig at you ALF, but there is clearly a large amount of misunderstanding on the subject among many here.

I would have thought FM, given the age of the vehicle you are looking at that any problems it may have had would have been resolved by now. If it's a dealer buy, ask if they will let you see the history.

Well, I don't know if you have followed the thread on my specific issues, but they seem far from unique. I too would have thought that at just under 3 years and 20k miles old my (originally £40k) car would have had any problems resolved when I bought it, but no. All that was on the history was one coil pack replacement at two years old.

I had two glorious months without trouble but then I had a misfire/warning light and a coil pack was replaced. The misfire came back a couple of weeks later and was on and off for a bit before becoming severe and constant again, this time first one then all the injectors were replaced over a number of days. Literally 10 miles into my trip home from all the injectors being done the misfire returned and a coil pack failure was diagnosed and it was replaced. Then it made it home but the very next day I used the car the problems came back - again intermittently - and this time a fourth coil failure was diagnosed but the coils were on backorder.

It would not be an exaggeration to say that since mid jan my car has been either in the dealership or showing a warning light and misfiring about half the time. That is something of an inconvenience given that I am home based and drive to appointments, often a long way away, for a living. Even when it is working it does noticeably "miss" for a split second quite regularly even when cruising on the motorway at 70. If that is problem that had been resolved before I bought the car then I'm a Chinaman. If the dealers knew exactly what was going on and how to fix it I suggest the course of events taken by my dealer in trying to sort my car out would not have happened. And I like my dealer, they seem competent and do seem to care, which is a first for any car marque for me.

Thanks for your post anyway as it offers the first logical explanation I have heard for the coil/plug failures - if the original injector programming was too lean and this damaged the coils/plugs over time then symptoms like mine are understandable and I'm glad my injectors have been replaced as presumably that means the latest software was applied at that time. But I still have two of the original coils - plus another one that had been running with the original injectors for a year - so it looks like I have at least two and possibly three potential failures to go.

I appreciate that there are some harsh comments about dealer competence on here, and I too feel that many of them are overly harsh in suggesting the failures are systemic or that there is an intent to defraud by not doing the work stated (though I know first hand of independents who have done exactly that) but it would be ridiculous to assert that they are perfect - for BMW or any marque. Too many people have first-hand stories about massive f*ck-ups and there are too many complaints made against the industry as a whole for car dealers to have any right to feel complacent. Not that feeling complacent and being defensive is a great attribute in any industry.

A couple of my war stories from my last car only - it lost boost with no warning lights appearing and the dealer suggested a turbo replacement at £3k. I looked on a forum and the turbo diverter valve is a very common failure on that (itself very common) engine so I ask them to change that first - £60 fitted. Problem fixed. Had they changed the turbo the problem would not have been solved as the diverter valve is not part of the turbo assembly on that engine, and that would have been £3k down the toilet. The same dealer changed my brake pads and a few trips later I get a vibration through the steering, pull over, and some of my wheel bolts have fallen out and the remainder are not even finger tight - on all 4 wheels.

If stuff like that never happened then we would all be very naughty boys for suggesting dealers are not perfect. Dealers have a hard job, as I said to the MD of mine when I met him recently - if they do a perfect job, we'll think they charge too much. If they don't do a perfect job, we complain. Cars are hugely complex. But given that when problems do occur they often take ages and a lot of work - at our expense - to fix, and that major f*ckups like the ones I mention above seem to occur quite regularly (don't even get me started on the various Alfa main dealers I've used...), it is no surprise forums like this exist and that people like myself with nothing but anecdotal mechanical knowledge try and work out for ourselves the answers to questions - a practice that as I mention has saved me £3k at least in the last year alone (in fact add another £1500 to that as only reading of the coil/injector issues on here made me buy a warranty for mine and that is the value of work already covered by it 2 months later).

[chrismanchr]

one question why does a coil failure cause an injector failure ? sure the fuel will be shut off to that cylinder if the coil fails to save the cats and emmisions but not break the injector

i had to replace all 6 coils on my porsche boxster ,they were very badly cracked and there was a distinct misfire and poor running cost me 220quid and was an easy job ,but transformed the car

[oab e90 330i se]

Ive just had my 2005 330i se (on 52k) disgnosed.
Missfire Cylinder 4 - Ignition coil.

I'm trying not to panic about the potential impending doom, having read all the problems people have. Am I right in saying that this particular model isnt as susceptable to 'all' of the problems listed in that previous long post. Or should I just give up now and let the car roll off a cliff.

Bottom line is, I love the car and my gut feeling is that I change out this Ignition coil today (one faulty coil) and continue on my happy way.

Or......I get paranoid and change all the Ignition coils at the same time! And the plugs, which are asking to be changed in 7k ?????????


Please reply, I'm new to this.