My eccentric sensor is bone dry. I'll try changing out the o2 sensors and see if that helps. The vanos is on the list of things to do, did you do the new seals or entire replacement? I did the seals on my 03 2.5i and it worked well. Not sure if it's any different on the n52 compared to the m54?
N52 hesitation, stuttering, jerking, surging etc
- Thread starter propaintballa
- Start date
propaintballa
Member
Our03z4 said:
Okay good regarding the ESS. It's different to the M54, VANOS rebuilds are not really commonplace on the N52. I have certainly not heard of anyone doing so. It's just the two solenoids at the front of the engine block that usually fail. A much less involved job. Takes 5 minutes to swap them over.
Glad that there is some progress on this. 95% of the problem being resolved is a forward step in my book.
On my response - the whooshing noise was unrelated. Hate to say a garage was right and all, but did turn out to be a heatsheild. Just made more of a noise as the exhaust moved around whilst the engine was under hard load from low RPM. James is very much right in the fact that there's rarely a 'single' cause of these issues though - it seems to be a cumulative effect.
Completely agree with the idea of making things run open loop. It sounds a bit lo-fi, but does move you forward as evidenced by the above.
I'm not really any further forward with mine. Just sort of accepted it as something the car occasionally does now and then and moved on with it. You can put in thousands with no end product if you're not careful.
On my response - the whooshing noise was unrelated. Hate to say a garage was right and all, but did turn out to be a heatsheild. Just made more of a noise as the exhaust moved around whilst the engine was under hard load from low RPM. James is very much right in the fact that there's rarely a 'single' cause of these issues though - it seems to be a cumulative effect.
Completely agree with the idea of making things run open loop. It sounds a bit lo-fi, but does move you forward as evidenced by the above.
I'm not really any further forward with mine. Just sort of accepted it as something the car occasionally does now and then and moved on with it. You can put in thousands with no end product if you're not careful.
Well after no issues for the past few weeks it came back with a vengeance, so much so I turned around and went home.
Starting to look into other cars. Went and test drove an Audi A8 the other day and I'm hooked, wife was too. If I can find a Audi S8, I'm out. Makes me sad because I really do love these cars, enough to have two currently, but this is just ridiculous!
I'm going to do one last repair blitz in hopes it will improve. Also it's sounding much louder all of a sudden, wife even commented on it. Not sure where that came from, almost sounds like the sound generator foam has been removed. Ideas?
Starting to look into other cars. Went and test drove an Audi A8 the other day and I'm hooked, wife was too. If I can find a Audi S8, I'm out. Makes me sad because I really do love these cars, enough to have two currently, but this is just ridiculous!
I'm going to do one last repair blitz in hopes it will improve. Also it's sounding much louder all of a sudden, wife even commented on it. Not sure where that came from, almost sounds like the sound generator foam has been removed. Ideas?
I don't think anyone involved with this issue would begrudge you having a look at something else if you're able to. In fact - if it were me I'd be running off into the hills - something I still haven't ruled out.
The only thing I'd query - is it rain related? I know we have been having a lot of late...
The only thing I'd query - is it rain related? I know we have been having a lot of late...
propaintballa
Member
Our03z4 said:
You note that it has gotten louder... I can't remember which car you have and what your problems were, but have you checked the intake pipe? They quite often crack and would likely create the sound you're describing if it has indeed perished.
I see there are 10 pages of this thread, so apologies if this has been raised. With the N52 engine, have you checked what spark plugs you have? IE, do you have the 4-pole plugs, and not the older single pole plugs? I've just watched a vid where the person was adamant this is the cause of a lot of rough idle problems. (ex-BMW dealer mechanic, seemed to know about the usual N52 problems - DISA valves, solenoids, rough idle, and many of the issues that get raised on this forum).
He pointed out that BMW changed to the 4 pole plugs (I think around 2008?) due to an 'update' - I got a bit confused around here so not sure what was updated (ECU?). Happy to link to the YT vid if you want.
He pointed out that BMW changed to the 4 pole plugs (I think around 2008?) due to an 'update' - I got a bit confused around here so not sure what was updated (ECU?). Happy to link to the YT vid if you want.
propaintballa
Member
enzed4 said:
I assume you are talking about "BMW Doctor". The guy is full of sht. I've watched a number of his videos, including that one, and I could see no mention of the 4 pole spark plugs he went on about in his video, on any of the BMW parts sites. As for updated parts, it's pretty common to see older parts superseded as they age, the coils were replaced with Delphi ones as opposed to the original Bosch ones, for example, but from my research, the plugs sadly are not one of them, but thanks for the response!
Yes, YT seems to be much better at entertainment than educationpropaintballa said:
. No one can find what's wrong with the handling in my Z4; I think the garages think I'm mad, but it's enough to make you look elsewhere if you just can't get it resolved satisfactorily. In the back of your mind is the constant nagging thought that it's something simple that's been overlooked, but as you eliminate one thing after another you eventually start giving up :xWell I changed out the vanos solenoids, seems to idle better, better power band, but still messed up a little while into the drive. Slight coolant leak is coming from the bottom o ring at the coolant tower, have all new on order. Think I might try the valvetronic motor next, if it doesn't work then I'll call it quits.
Checked all the intake lines and they seem to be in great condition.
Checked all the intake lines and they seem to be in great condition.
Well I guess my car had to adapt to the new solenoids because it's running so much better! Still feel the back and forth motion but rarely and when I do it's barely noticeable. Also found that the auto transmission thermostat was broken and stuck in the open position. Didn't even know about the part until replacing the coolant tower, luckily the local dealer had one in stock. Now I just have to tackle the wiper fluid leak for the headlights. Love this car again, thanks guys!
propaintballa
Member
Haven't updated this for a while because I felt like the problem had been resolved. However, it has become apparent that it in fact still exists. Most prominently the problem is this weird pulsing/hunting idle, but also the old symptoms of hesitation when flooring the throttle and surging around 2k rpm.
I thought my large DISA could have broken by now, like the small one, so I thought I'd whip it off to check. I quickly discovered that the DISA is fine, but I had about the same amount of oil come out of my intake as when I replaced the CCV back in March 19 some time. After I replaced the CCV, I noted that removing the oil cap with the engine running meant the car would eventually stall, which it didn't before and didn't on my old Z4C with the N52B30. It is unclear as to whether it is supposed to continue running normally, or stall, despite people citing this action as a way to test the function of the CCV. I am beginning to doubt the quality of the CCV kit due to these issues and the fact I didn't use genuine replacement parts.
This however doesn't explain why the car ran SO much better when I unplugged the old o2 sensors, which eventually lead me to replace them. This car continues to baffle me!
I thought my large DISA could have broken by now, like the small one, so I thought I'd whip it off to check. I quickly discovered that the DISA is fine, but I had about the same amount of oil come out of my intake as when I replaced the CCV back in March 19 some time. After I replaced the CCV, I noted that removing the oil cap with the engine running meant the car would eventually stall, which it didn't before and didn't on my old Z4C with the N52B30. It is unclear as to whether it is supposed to continue running normally, or stall, despite people citing this action as a way to test the function of the CCV. I am beginning to doubt the quality of the CCV kit due to these issues and the fact I didn't use genuine replacement parts.
This however doesn't explain why the car ran SO much better when I unplugged the old o2 sensors, which eventually lead me to replace them. This car continues to baffle me!
I took the liberty of checking what happens when I open the oil cap with the engine at idle on my N52K and posted a Youtube video below. You can see that the idle speed does not change at all and there is light suction that can be heard and felt as the cap is opened and closed. This is the blacktop N52K but assume the silver top N52 will be similar.....
https://youtu.be/VhcqVSkhIeA
https://youtu.be/VhcqVSkhIeA
UPDATE: i suffered with the jerky acceleration issues and recurring knock sensor fault codes ever since I bought my 2008 2.5i, as you will see in the post and some of my own I had tried all sorts but eventually gave up and just got used to clearing my fault codes whenever I didn’t want a lumpy acceleration. Anyway over winter and partly because I hadn’t driven it much because I’m shielding I decided to renew the battery, it turned out I had the original 2008 battery still fitted 
Now I have a brand spanking new Battery I have not had any issues with the acceleration or any fault codes at all since 
my only explanation was the battery dipped too low on start ups that it affected the knock sensor readings, throwing up a fault which the car then tried to compensate for. Very happy now, over two years of ownership and it drives better that ever now
Now I have a brand spanking new Battery I have not had any issues with the acceleration or any fault codes at all since my only explanation was the battery dipped too low on start ups that it affected the knock sensor readings, throwing up a fault which the car then tried to compensate for. Very happy now, over two years of ownership and it drives better that ever now