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Hello, I have a 2009 Bentley continental Spur speed, I have random missfire on cold start or first start of the car.
the engine Rpm go up and down and I hear a hissing noise on top of the engine...
is that coil & plug or it has vacuum leak? I saw the 2009 one doesn't has the Line on top of the transmission but I hear the hissing sound pretty loud
Thank you
Sunday,04,August,2019,23:27:38:47143
VCDS Version: Release 19.6.1 (x64) Running on Windows 7 x64 www.Ross-Tech.com
Address 11: Engine II Labels: 07C-906-018-BWR2.clb
Control Module Part Number: 07C 906 018 FA HW: 07C 906 018 ET
Component and/or Version: BY - 6.0 L - TT G ª3135
Software Coding: 0021175
Work Shop Code: WSC 00083 790 00000
VCID: E99A3C95C1C14507AE-5160
7 Faults Found:
000768 - Random/Multiple Cylinder Misfire Detected
P0300 - 001 - - MIL ON
Freeze Frame:
Fault Status: 11100001
Fault Priority: 0
Fault Frequency: 1
Reset counter: 255
Mileage: 82860 km
Time Indication: 0
These are all misfires on the leftside cylinder bank. Leftside is defined from the position of sitting in the seat (always) and looking out the windscreen.
So, along with the hissing you're hearing, find that source on the left side bank and you'll find the problem. It is likely a massive air leak such as one of the hoses slipped off the intercooler or a cracked or leaking inlet pipe somewhere leftside.
Here is another example where spark plugs and/or coils are pretty low to the bottom of the list of places to look for the problem.
Another possibility, if the hissing is during the initial startup, apx. 60 seconds and never heard again during the drive cycle possibly secondary air pump? Regarding the secondary air pump if one of the hoses either came off or cracked it's going to create a loud blowing sound, which would sound like a vacuum leak as well. However can't confirm if that would create a misfire.
Then again one of the PCV hoses cracking or disconnected would create a loud continuous hissing sound while driving. That type of vacuum leak could create a misfire. Also as Mr BWwing stated on another thread make sure the oil dipstick is securely seated. The dipstick is a potential vacuum leak area when not properly pushed into place.
PS. Please post the timing and duration of the vacuum hissing sound.
I had these or very similar codes reference to random missfire so I bought all new could packs and plugs but when investigating the hissing I found this? It was on a plastic pipe from the rocker cover goes under air filter box
I had these or very similar codes reference to random missfire so I bought all new could packs and plugs but when investigating the hissing I found this? It was on a plastic pipe from the rocker cover goes under air filter box
That is the PCV hose. A faulty design piece of crappy plastic that will fail and cause grief.🤤😉
After I did a smoke test with the help of Bentleytech here.. I found out the problem is leaking PCV valve...
The diaphragm got crack...
here is the picture of it
after replace the diagphrame that I got an Issue with the Engine running rich.. the fuel trim is way down to -25%.. anyone can point out what wrong with it.
THank you
After I did a smoke test with the help of Bentleytech here.. I found out the problem is leaking PCV valve...
The diaphragm got crack...
here is the picture of it
after replace the diagphrame that I got an Issue with the Engine running rich.. the fuel trim is way down to -25%.. anyone can point out what wrong with it.
THank you
will it take a while for ECU to obtain correct mixture and air ratios as it has been running with faulty pcv?
will it take a while for ECU to obtain correct mixture and air ratios as it has been running with faulty pcv?
Yes, precisely. Fuel trims do not correct with the snap of a finger. However, if you disconnect battery power and drain all capacitance out of the system (takes about one or two minutes grounding the positive battery terminal to ground, disconnected from the battery of course) the LTFTs will be lost. Upon reconnection, the LTFTs will reestablish more quickly.....or, drive the car 50 miles or so and check again.
BTW, FTs on only one bank? Or both?
If fuel trims are staying at -25%, then you want to start looking at other things, the first of which would be:
Leaking fuel injectors
Bad fuel pressure regulator
Bad MAF
weak/bad O2 sensors
But, at least try to let it self clear before chasing a possible non-issue.
I uploaded an Youtube video about my fuel trim, Both are perfect but sometime the bank 2 just suddenly go down to -25%
I think Maybe I have wiring issue so it effect the MAF reading...
I will check wiring then let you guy know.
thank you a lot
@Bwings : if u read my Fuel Trim do u think my injector is ok?
I uploaded an Youtube video about my fuel trim, Both are perfect but sometime the bank 2 just suddenly go down to -25%
I think Maybe I have wiring issue so it effect the MAF reading...
I will check wiring then let you guy know.
thank you a lot
@Bwings : if u read my Fuel Trim do u think my injector is ok?
Hi NG:
You mention bank 2, but this video is of bank 1. The important metric to watch is long term FT, not short term FT. If I were commenting on this bank 1 you are maintaining a LTFT of 4.7. That is pretty perfect. When I set fueling in tunes that I do I try to maintain + or - 3%, but it is very difficult to do and with age and wear, the numbers always widen after the tune. +- 5% is a standard. Those could drift to as much as +- 8/9% with time/wear.
Some other observations about bank 1, in this video you are maintaining a pretty narrow RPM band so it is difficult to make any deductions from such a narrow RPM. Fueling will be adjusted by the ECU for many conditions beyond just maintaining a stoichiometric 14.7:1 AFR. I can tell moments when you released the throttle when short term fuel moved momentarily to 25% then back. All engine management systems use an "overfueling moment" upon deceleration. In this moment, fueling turns very rich. It is fueling technique to chill cylinders as the engine comes off of a higher RPM. This one factor has fooled many as they try to watch STFTs. Right after that, the EMS builds in what is called deceleration/fuel cutoff (DFCO). This comes a moment after throttle release until treturn to idle. None of your video actually returned to idle but if it had, and as the system stayed in closed loop, STFTs would turn very lean (as the enviromental protection agencies would like).
The only way to really start analyzing LTFTs to the level of determining whether you have dirty or sticking fuel injectors or a MAF with dropouts is through a much wider RPM range at a NORMAL outside air temp and a healthy coolant system. Once above 86*F air temps (approximately 30*C) the EMS is now adjusting timing. If the coolant temp rises past 225*F, there is an ADDER that is used on the fueling regardless of what the O2 sensors signal and what the MAF frequencies are.
Finally, this is not likely with a Bentley (possible but not usually probable) if anyone has intervened in the tune, a good tuner can manipulate any data to achieve almost any outcome (within the laws of physics of course). I'll give you just a small example using MAF frequency. And BTW, when MAFs go bad sometimes they have dropouts. Dropouts is something I can probably spot on a LOG if I have a good RPM range recording with all other normal conditions
A normal MAF frequency output through the RPM range graphs something like this:
On an engine I tuned where a centrifugal supercharger was added I modified the frequency table to look like this:
The delta in the modded range compared to the stock MAF range looked like this:
I needed to "fool" the ECU into thinking it was seeing more or less air volume than it actually was receiving to achieve some momentary fueling needs of the boosted engine. This also was a MAF only tune and speed density was turned off (ECU was not allowed to use the VVE table for fueling, only the MAF and O2 sensor inputs).
If I saw certain erratic changes in fueling STFTs enough to move LTFTS through the complete RPM range and back where all else was normal (coolant, air temps, baro etc.,) on an UNTUNED engine, I could start to point to injectors, or a MAF. Even O2 sensors as possible problems.
Sorry for all this length. Again, hopefully I haven't missed what you were asking but it looked like you were showing bank 1, mentioning FTs on bank 2. Please post that side, but try for an etended RPM range (idle through 5KRPMs and back to idle) . That should show evidence of PE as well.
@BWings
If u scroll to the minutes 5:13 up there will be a bank 2
because I'm doing screen recording on iphone so I can only record one bank on each time.
Thank you
@BWings
If u scroll to the minutes 5:13 up there will be a bank 2
because I'm doing screen recording on iphone so I can only record one bank on each time.
Thank you
OK maybe I missed it changing. I'll look at it again.
@Bwings maybe I have a problem with MAF or Wiring to MAF.. Suddenly it read 7.86gs/s at idle while it only should read 3.86gs.s
I will check the wiring then let u know
Wednesday,07,August,2019,11:41:16:47143
VCDS Version: Release 19.6.1 (x64) Running on Windows 10 x64 www.Ross-Tech.com
Address 11: Engine II Labels: 07C-906-018-BWR2.clb Control Module Part Number: 07C 906 018 FA HW: 07C 906 018 ET
Component and/or Version: BY - 6.0 L - TT G ª3135
Software Coding: 0011175
Work Shop Code: WSC 00046 000 00000
VCID: E99A3C95C1C14507AE-5160
2 Faults Found:
008576 - Bank 2; System Too Rich off Idle
P2180 - 002 -
Freeze Frame:
Fault Status: 01100010
Fault Priority: 0
Fault Frequency: 1
Reset counter: 255
Mileage: 83022 km
Time Indication: 0
With a P2180, especially on this car, it could be -
A wiring issue, a sensor issue, or a faulty fueling component issue. Remember the simple closed loop process (engine coolant at normal operating temp) at idle all the way up to Power enrichment (about 3500/3800 rpm to redline). The ECU fuels (commands the injectors) based on a table that converts MAF frequency to g/s and based on injector data, then receives a signal from the O2 how much fuel was left unburned in the exhaust. The ECU then uses an "adder" to the table for the next cycle based on whether that signal comes back high voltage (rich) or low (lean). This is the SIMPLE process. Many other input signals also impact the ECUs decision to fuel by the use of "adders", but we need to focus on those 4 items:
MAF sensor,
O2 sensor,
ECU
fueling system (wiring, components)
Do the easiest to the hardest.
Wiring easiest (except the leftside O2 sensor):
Check the harness to the MAF
You will not be able to check wiring issues on the O2 sensor.
ECU harness corrupted (classic failure on the Bentley Continentals)
Sensors are next:
Check for input voltage to the MAF with engine running - use a simple voltage meter + to red wire, - to ground.
Similarly, check the other wires for voltage out - low v at idle, increasing v as engine RPM increases. I cannot tell you which color. check the all. One of the outputs on bank 2 MAF will be the IAT. It should be a steady v. This is what I was trying to portray above using the MAF frequency graphs. In the first graph, MAF output frequency is directly related to MAF output voltage. When you find the output wire you should see a low to high v range related to engine RPM. You will not be able to see frequency in hz without specialized invasive software, but voltage is simple with a volt meter.
O2 sensor best checked with a datalog. Look for a sine like wave after engine is warmed up and in closed loop. Engine goes into closed loop approximately at 105*F engine coolant temp. Look for a mv range of 100mv to 900mv. If the O2 sensor is defective it might not be switching at idle but works at higher rpms. (bad O2 sensor).
If the MAF wiring and sensor are healthy, same with the O2 sensor, then you must move to harder diagnosis:
Fueling components - injectors dirty, stuck open, pressure regulator,.
Could also be the EVAP cannister, purge regulator valve (although I haven't heard of many issues on Bentley, this is often the problem on other cars).
Faulty ECU - This is almost a default diagnosis. - When all else fails.....
Hope this wasn't too long. These are the areas to begin.
08-04-2019, 11:13 AM
