M5 engine problems
Discussion
My M5 has just returned from the dealer for the second time 
. Over the last couple of months it's developed an intermittent problem.
Basically, if you're 'pressing on' (I would say 'thrashing' it, but that's not true
) at high revs it suddenly loses power and behaves as if the mixture is heroically wrong, someone's unplugged a couple of plug leads, or stuffed a banana up one of the exhaust pipes.
If you back off, you find that for the next 5 mins or so you can use part throttle, but if you try and accelerate even slightly agressively it refuses to run smoothly. It's a kind-of 'fluttering' sensation.
Anyway, the local dealer changed a camshaft sensor the first time. This did bugger all, but today they had the car for 7 hours or so and spent nearly all that time running diagnostics. Apparently all they found was 16 'logged' misfires which pointed to a cam sensor (again). They cleaned some oil filter, and also re-set the adaptive maps (they said they found a problem at one of the map points). The best part was that they did this all FOC (which was nice!
).
Anyway, we'll see how it goes, but I just wondered if anyone else had had similar problems, and whether you successfully cured the problem?
PS. Anyone going to VW this weekend from here?
. Over the last couple of months it's developed an intermittent problem. Basically, if you're 'pressing on' (I would say 'thrashing' it, but that's not true
) at high revs it suddenly loses power and behaves as if the mixture is heroically wrong, someone's unplugged a couple of plug leads, or stuffed a banana up one of the exhaust pipes. If you back off, you find that for the next 5 mins or so you can use part throttle, but if you try and accelerate even slightly agressively it refuses to run smoothly. It's a kind-of 'fluttering' sensation.
Anyway, the local dealer changed a camshaft sensor the first time. This did bugger all, but today they had the car for 7 hours or so and spent nearly all that time running diagnostics. Apparently all they found was 16 'logged' misfires which pointed to a cam sensor (again). They cleaned some oil filter, and also re-set the adaptive maps (they said they found a problem at one of the map points). The best part was that they did this all FOC (which was nice!
). Anyway, we'll see how it goes, but I just wondered if anyone else had had similar problems, and whether you successfully cured the problem?
PS. Anyone going to VW this weekend from here?
yes . see my posts in M5 Finally.
Sounds like the O rings in the Vanos system. Insist they change these. common problem so I learn, although garage wont try this until last as they take half the engine apart.
Be very careful as you dont want a loss of power pulling away from a junction or roundabout.
Sounds like the O rings in the Vanos system. Insist they change these. common problem so I learn, although garage wont try this until last as they take half the engine apart.
Be very careful as you dont want a loss of power pulling away from a junction or roundabout.
until they took apart the vanos, they replaced air sensors, fuel pump, both cats, (get them to check the cats anyway as mine were fallingapart but wernt the problem) and finally engine management software to the new M5 just out.
sorry to hear of your problems. not much fun. and dangerous.
sorry to hear of your problems. not much fun. and dangerous.
superlightr,
Thanks for the feedback - they have advised that we 'try it' for a week or so, and potentially bring it back so the chief techie can drive around in it for a while, if its still 'doing its thang'.
So far, I can report that the cold running (first 5 mins) is much improved; less sensitive to throttle and we've got rid of the annoying rev-die-rev-die-rev which always happened when reversing.
But if you've had the same problem I might take it back anyway. I'm going to have trouble, though, cos they have already swallowed (allegedly) £700 worth of diagnostics which aren't covered by the warranty. So anything else is likely to be chargeable
Thanks for the feedback - they have advised that we 'try it' for a week or so, and potentially bring it back so the chief techie can drive around in it for a while, if its still 'doing its thang'.
So far, I can report that the cold running (first 5 mins) is much improved; less sensitive to throttle and we've got rid of the annoying rev-die-rev-die-rev which always happened when reversing.
But if you've had the same problem I might take it back anyway. I'm going to have trouble, though, cos they have already swallowed (allegedly) £700 worth of diagnostics which aren't covered by the warranty. So anything else is likely to be chargeable
if its still within the warranty it should all be covered under warranty.
I had the same thing, like a yo yo, in out in out and the problem not fixed. Its bloody dangerous when the power cuts out. Mine was fine after the vanos system was taken apart. Oil was leaking past the o rings.
I too had poor cold weather, inital start up fluctuations in the revs. Each time they would do something it would be ok for about 1 week and then loss of power/ hesitency.
Trust your own judgement. Mine had the rear anti roll bar break whilst I was overtaking and almost lost control, when I took it to the garage to say the rear wasnt handling right their 'best' test driver/cheif mechanic took it out who 'had lots of expierence of M5s' and could not feel the difference.
Only when I inisted that they look underneath that found it had broken. 'never sean this before Sir'. Bollx.
make sure you have the cats inspected. mine had broken apart - falutly manufacutre and initally thought it was causing the loss of power ie blocking the exhaust gasses, they changed them and still no sucess.
I think the problem caused the cats to break up so thats why I suggest you have them checked. If mine wasnt within warranty the cats I think are £500 each.!
See if you can extend your warranty if you intend to keep the car.
Please post on how you get on. My sympathys to you as its not fun, very stressful and dangerous. BMW know there is a vanos fault with the M5 engine.
good luck,
I had the same thing, like a yo yo, in out in out and the problem not fixed. Its bloody dangerous when the power cuts out. Mine was fine after the vanos system was taken apart. Oil was leaking past the o rings.
I too had poor cold weather, inital start up fluctuations in the revs. Each time they would do something it would be ok for about 1 week and then loss of power/ hesitency.
Trust your own judgement. Mine had the rear anti roll bar break whilst I was overtaking and almost lost control, when I took it to the garage to say the rear wasnt handling right their 'best' test driver/cheif mechanic took it out who 'had lots of expierence of M5s' and could not feel the difference.
Only when I inisted that they look underneath that found it had broken. 'never sean this before Sir'. Bollx.
make sure you have the cats inspected. mine had broken apart - falutly manufacutre and initally thought it was causing the loss of power ie blocking the exhaust gasses, they changed them and still no sucess.
I think the problem caused the cats to break up so thats why I suggest you have them checked. If mine wasnt within warranty the cats I think are £500 each.!
See if you can extend your warranty if you intend to keep the car.
Please post on how you get on. My sympathys to you as its not fun, very stressful and dangerous. BMW know there is a vanos fault with the M5 engine.
good luck,
Wierd you guys should say this; when I recently (finally) drove one, I must say, I do recall sensing a certain hesitancy in power delivery: it felt at times more like slight turbo lag rather than normal aspiration...
Looks like SuperlightR is/was right!
Does this mean that the holiest of holies is nobuta farmyard animal that goes gobble?
Looks like SuperlightR is/was right!
Does this mean that the holiest of holies is nobuta farmyard animal that goes gobble?
hi Derestrictor, The hesitancy was a loss of power, not just a little but 90% loss of power.
Although after a time you learnt to feel that there were tale tale signs before it did it, ie the revs would not sit quite right, my accelarater pedal 'clicked' now and again - feedback even though it was fly by wire!?!
There was a hesitancy - yes looking back a bit like turbo lag about a week before it lost it power. just little signs that something not quite right but at the time you pass it over as a bump in the road, one of those things, imagination .
as i understand as more oil went past the o rings it caused more severe misfire(s) which also also caused other sensor failurs ie exhaust gasses were wrong, mixture sensors etc and then the car goes into a limp home mode.
The oil leakage apparantly takes time to build up and then revs fluctulate, and then a few mins/sec later loss of 90% power.
I wouldnt let Mrs SuperlightR drive as the car was so unpredictable, not just the loss of power but all the other things that happened as well. Although the loss of power is critical and dangerous in itself.
I imagin Most people here on PH are sensitive drivers to their cars and how they behave and work and most can feel when things arnt right. make sure you follow you instincts as you will probably be right.
>> Edited by superlightr on Monday 3rd February 12:52
>> Edited by superlightr on Monday 3rd February 12:57
Although after a time you learnt to feel that there were tale tale signs before it did it, ie the revs would not sit quite right, my accelarater pedal 'clicked' now and again - feedback even though it was fly by wire!?!
There was a hesitancy - yes looking back a bit like turbo lag about a week before it lost it power. just little signs that something not quite right but at the time you pass it over as a bump in the road, one of those things, imagination .
as i understand as more oil went past the o rings it caused more severe misfire(s) which also also caused other sensor failurs ie exhaust gasses were wrong, mixture sensors etc and then the car goes into a limp home mode.
The oil leakage apparantly takes time to build up and then revs fluctulate, and then a few mins/sec later loss of 90% power.
I wouldnt let Mrs SuperlightR drive as the car was so unpredictable, not just the loss of power but all the other things that happened as well. Although the loss of power is critical and dangerous in itself.
I imagin Most people here on PH are sensitive drivers to their cars and how they behave and work and most can feel when things arnt right. make sure you follow you instincts as you will probably be right.
>> Edited by superlightr on Monday 3rd February 12:52
>> Edited by superlightr on Monday 3rd February 12:57
Sounds exactly like what I had. I took it to two garages before the garage that supplied it (Radfords in Stafford) fixed it. I actually had the engine stop at 100 mph on the M27, very scary and potentially lethal. BMW where so shocked they gave me a nice new 735i to drive around it while they fixed it.
Oh dear. Things are going downhill. Took the car out yesterday, about 15 mins into the journey I took the opportunity to put my foot down, and at about 5500 rpm I changed up. It was a bit of a violent 'cut' of power which I thought was odd. Picked the next gear, put my foot down again and .. nothing. No power at all 
.
We ground to a halt (engine still running) and worked out that it wouldn't rev over 3k revs. Must be a 'get home' mode or something. Everything else seemed fine. Got home, turned engine off, waited 10 sec, turned it on again and it revved fine. Must quiz BMW as to whether their ECU runs Windows ..
Anyway, the upshot is that i'm going to take the car in tomorrow morning to the local dealers and have a serious chat with them about o-rings. Superlightr, could you let me know which dealer fixed your car eventually? I'd like to be able to get them to talk to each other.
. We ground to a halt (engine still running) and worked out that it wouldn't rev over 3k revs. Must be a 'get home' mode or something. Everything else seemed fine. Got home, turned engine off, waited 10 sec, turned it on again and it revved fine. Must quiz BMW as to whether their ECU runs Windows ..
Anyway, the upshot is that i'm going to take the car in tomorrow morning to the local dealers and have a serious chat with them about o-rings. Superlightr, could you let me know which dealer fixed your car eventually? I'd like to be able to get them to talk to each other.
Very sorry to hear its still not fixed.
I had to get shitty with BMW GB in the end. The BMW dealer who worked on mine was Vines in Crawley/Gatwick Sussex.
Be very careful with the car, In the end we lodged our complaint letters with our solicitors and a crash investigator in case we didnt come back one day.
no wonder i wont touch another BMW again. Let me know how you get on, if I can help i will try. BMW GB are fully aware of this problem and im amazed that they have not recalled the M5. someone will die if they havnt already becasue of this fault.
Have a look at M5 Finally for some further details of my problems, not just with the engine.
Good luck and spit flames at them,
.
I had to get shitty with BMW GB in the end. The BMW dealer who worked on mine was Vines in Crawley/Gatwick Sussex.
Be very careful with the car, In the end we lodged our complaint letters with our solicitors and a crash investigator in case we didnt come back one day.
no wonder i wont touch another BMW again. Let me know how you get on, if I can help i will try. BMW GB are fully aware of this problem and im amazed that they have not recalled the M5. someone will die if they havnt already becasue of this fault.
Have a look at M5 Finally for some further details of my problems, not just with the engine.
Good luck and spit flames at them,
.
Veeeeeery interesting, superlightr. Ta very much for the information about the dealer. I also posted on bmwm5.com and some guy has also had the same problems and has given me the name of a chap who I should ask my dealer to contact.
The thot plickens ..
(many thanks for the info, btw -
- it's this kind of information which is worth its weight in gold to me)
The thot plickens ..
(many thanks for the info, btw -
- it's this kind of information which is worth its weight in gold to me)Hmmm. Car just cut out for the second time. My wife was driving it, went to overtake, and it just cut out. Took it straight back to the dealer and they reckon it's airflow sensors. According to them, the ECU shut down to <3000 rpm to protect the Cat's. Hmmm. Since i've just removed them from the Cerb, and realise how little they do to save the environment anyway, i'd much rather try to save my wife & son by preserving engine power than the bl**dy cats.
Anyway, apart from this recent mishap, I mailed the dealer about 2 weeks ago with lots of information about the possible problems, but got NOTHING in reply. Only after I mailed him again, then again, then phoned and left a message did he call me back. This was two days ago. His only question was: "Has it happened again?". I said no - he said "good - looks like we've fixed it, then". Famous last words? Looks like it.
Am going to call him on Monday and have a right rant at him. I can't believe that they were so certain that it was sorted, then almost the next day it happened again.
Anyway, apart from this recent mishap, I mailed the dealer about 2 weeks ago with lots of information about the possible problems, but got NOTHING in reply. Only after I mailed him again, then again, then phoned and left a message did he call me back. This was two days ago. His only question was: "Has it happened again?". I said no - he said "good - looks like we've fixed it, then". Famous last words? Looks like it.
Am going to call him on Monday and have a right rant at him. I can't believe that they were so certain that it was sorted, then almost the next day it happened again.
futie, change the car. This is exactly the sh*t I had with mine, air sensors, this and that sensors, fuel pumps, cats etc. None worked.
Cut your loses before you or your wife end up in a crash. Its not worth the stress or potential loss of life.
I had hoped they had fixed it as hadnt heard from you for ages- (was also begining to hope that you had not had a mishap also.)
Have they taken apart the vanos and the o rings? Insist they do, get them to call Gatwick (crawley) BMW
you have got to go ape at them.
did you wife get any 'clicking' feedback in the acceleratior pedel just before? or a small hesitency a few secs or mins before?
Cut your loses before you or your wife end up in a crash. Its not worth the stress or potential loss of life.
I had hoped they had fixed it as hadnt heard from you for ages- (was also begining to hope that you had not had a mishap also.)
Have they taken apart the vanos and the o rings? Insist they do, get them to call Gatwick (crawley) BMW
you have got to go ape at them.
did you wife get any 'clicking' feedback in the acceleratior pedel just before? or a small hesitency a few secs or mins before?
Superlightr - the car is getting worse which is a good/bad thing I guess! It cut out twice on Saturday whilst I was driving it - simply accelerating up a slip road onto the A34!
I pulled over, restarted the engine, and all was fine again.
Anyway, tried to rant at my dealer this morning, but the guy i'm dealing with was 'with a customer'. The other person I spoke to recommended that I get the car recovered also! So I think I might arrange that for this afternoon.
The reason for replying is to ask you, superlightr, for either your surname or reg. number. Please feel free to mail me offline - i've just spoken to the very friendly Duncan at Vines of Gatwick and he needs these details before he can do a search for your car. If you're happy to give these out, then great.
On another note, a chap on bmwm5.com has given me the name of a guy at BMW GB who has diagnosed & fixed this problem before. So I called them, and got another friendly lady who took all my particulars!
So.. things are moving forward. Still got a car which doesn't work and is dangerous to drive, though.
I pulled over, restarted the engine, and all was fine again.
Anyway, tried to rant at my dealer this morning, but the guy i'm dealing with was 'with a customer'. The other person I spoke to recommended that I get the car recovered also! So I think I might arrange that for this afternoon.
The reason for replying is to ask you, superlightr, for either your surname or reg. number. Please feel free to mail me offline - i've just spoken to the very friendly Duncan at Vines of Gatwick and he needs these details before he can do a search for your car. If you're happy to give these out, then great.
On another note, a chap on bmwm5.com has given me the name of a guy at BMW GB who has diagnosed & fixed this problem before. So I called them, and got another friendly lady who took all my particulars!
So.. things are moving forward. Still got a car which doesn't work and is dangerous to drive, though.
Superlightr, many thanks for the details. I called Duncan back and we talked about the (many!) parts replaced on your car. However, although the list showed work on the o-rings on your car, the last entry (date order) was a change to both air-mass-flow meters on the engine. This is currently what my local dealer are replacing, so I wonder whether this might be the actual cause of the problem? It certainly seems plausible - do you remember when these were changed - was this related to the problem, or not?
I'm going to wait until i've spoken directly with BMW GB about this one - i've left a message and will chase them today, but it would be interesting to see if their thoughts tally with those of Vines/Gatwick and my local dealer.
Once again, many thanks for your details - I actually feel like i'm helping to sort this problem, rather than leaving it in the hands of my dealer.
PS. What's your favourite tipple - i've got to repay you somehow!
I'm going to wait until i've spoken directly with BMW GB about this one - i've left a message and will chase them today, but it would be interesting to see if their thoughts tally with those of Vines/Gatwick and my local dealer.
Once again, many thanks for your details - I actually feel like i'm helping to sort this problem, rather than leaving it in the hands of my dealer.
PS. What's your favourite tipple - i've got to repay you somehow!
Hope i'm not boring anyone, but a quick update! 
:
Car is still with dealer, we have a 'BMW Assist' Ovlov until Monday. They have replaced the airflow 'mass' -ometers (technical term) and have not managed to reproduce the fault today. I mailed them the other day describing the fault in detail, and how to reproduce it along with the 'flat spot' at 5000rpm and the bad cold running, so I assume they know what they should be doing!
However, on the test drives they noticed a 'knocking' which I reported to them the first time it came in for this 'cutting out' fault (they said they couldn't find anything and they'd 'tightened everything up' just in case) and have decided it's something to do with the steering rack and think it's serious enough to keep in.
So .. car still in garage, major fault potentially fixed (but we still have a new ECU or software on order) and new fault with steering rack awaiting a fix.
Ho hum.
: Car is still with dealer, we have a 'BMW Assist' Ovlov until Monday. They have replaced the airflow 'mass' -ometers (technical term) and have not managed to reproduce the fault today. I mailed them the other day describing the fault in detail, and how to reproduce it along with the 'flat spot' at 5000rpm and the bad cold running, so I assume they know what they should be doing!
However, on the test drives they noticed a 'knocking' which I reported to them the first time it came in for this 'cutting out' fault (they said they couldn't find anything and they'd 'tightened everything up' just in case) and have decided it's something to do with the steering rack and think it's serious enough to keep in.
So .. car still in garage, major fault potentially fixed (but we still have a new ECU or software on order) and new fault with steering rack awaiting a fix.
Ho hum.
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