Unfortunately we do not accept new members for free, Now Registration cost 30€, if you are interesting Send Email to [email protected]

Help interpret valve angle and vaccum readings from an E87
28-07-2018, 09:28 AM, (This post was last modified: 28-07-2018, 09:32 AM by willisodhiambo.)
Post: #1
Help interpret valve angle and vaccum readings from an E87
I have a car that seems to loose power at higher revs over 2000 and occasional hunting idle or jacking at around 3000k. I have run checks and I find two queer things,

1. Intake vaccum is reading a massive 353hPa at idle. From memory it should be around 50hPa or 100hPa. No way it can be half atmospheric pressure. DME has not flagged it but when I run pressure vaccum sensor test, it is flagged as faulty. With ignition off it reads zero as expected. I had a car before with a similar issue and replacement of the sensor did not cure the fault, nor replacement of DME. What else can I check for? I don't see where the huge vaccum is coming from yet car idles OK most of the time.

2. The valve position is quite confusing. Both intake and exhaust seem to erratically shift position from 90degrees to massive figures like 600degrees at idle. It makes no sense. Almost as if the cam position sensors are faulty. But how can both go faulty? And since car fires, they are surely working.

Am I missing something?

I have taken snapshots on diagnosis.


Attached Files
cam.rar
File Type: .rar
Downloaded: 4 times
Size: 11.26 MB

Vaccum.rar
File Type: .rar
Downloaded: 2 times
Size: 3.45 MB

Quote this message in a reply
28-07-2018, 15:51 PM,
Post: #2
RE: Help interpret valve angle and vaccum readings from an E87
for maybe you have poor timing chain, poor timing altering the inlet vacuum and also the timing values.
check timing chain for slack and for correct alignment, timing.
Quote this message in a reply
30-07-2018, 07:43 AM,
Post: #3
RE: Help interpret valve angle and vaccum readings from an E87
(28-07-2018, 15:51 PM)interested Wrote:  for maybe you have poor timing chain, poor timing altering the inlet vacuum and also the timing values.
check timing chain for slack and for correct alignment, timing.

Possible, will be an item to check for sure. I wonder though if incorrect timing should cause the spikes in the valve timing as read from the cam position sensors.
Quote this message in a reply


Possibly Related Threads…
Thread Author Replies Views Last Post
XZBMW F30 (MUE) / 8E12 EGS fault 44D371 PS Solenoid Valve: Faulty rana 3 518 04-05-2023, 18:09 PM
Last Post: Node
  Eps errors but wheel works EPS torque sensor (steering angle index): Index Faulty bmwlover 11 1,293 17-10-2022, 21:42 PM
Last Post: LeonidLunin
  2008 BMW 128i Stearing angle sensor issues koziol 3 530 19-07-2022, 08:30 AM
Last Post: Rwik5070
XZBMW N54 Wastegate Control Vacuum Readings BMWCraft 0 205 24-06-2022, 22:17 PM
Last Post: BMWCraft
  BMW Fx exhaust pipe exhaust valve Open code borhanlin 0 424 20-10-2019, 13:00 PM
Last Post: borhanlin
XZBMW 8HP45 transmission mechatronics matching on valve body -- BMW F30-- 316i - 2012year jonazizbey 5 610 01-10-2019, 08:03 AM
Last Post: Alexandru.k_24
  E71: recode dsc module steering angle sensor Fx82 3 1,143 25-01-2018, 21:30 PM
Last Post: Fx82
  Help please...vdm throttle valve on313no 0 597 26-08-2017, 17:50 PM
Last Post: on313no
  BMW X3 2008 steering angle sensor alignment cotymoto 5 2,076 28-09-2014, 14:08 PM
Last Post: cotymoto

Forum Jump:


Users browsing this thread:
1 Guest(s)

Return to TopReturn to Content