Cold start problem with video evidence

[rmoconnor41]

I have been asking for advice on a “cold” start issue without evidence to show what the 2.8 is doing.

This you tube link shows th vehicle at it’s worse.

No air leak good quality MAF. ICV good. Currently no codes although previously it would throw trim codes.

with thank for your suggestions.

Richard

- YouTube

Enjoy the videos and music that you love, upload original content and share it all with friends, family and the world on YouTube.

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[Sajk]

What is that clunk every time the revs drop.

What is the mileage? Does it dissappear completely when warm?

Is it an m52tu? Double vanos.

It may be the vanos seals. Idle instability is one of the symptoms

 

[rmoconnor41]

Thanks
Don’t know
98K
Yes
Yes
Yes
Last year it had a Vanos rebuild

 

[NZ00Z3]

Rather than ask a 1,000 questions, can I get you to run a few data logs and post links to the logs here. I do a lot of analysis on the logs and can generally find the problem.

You will need:
- An OBD adapter, either WIFI or Bluetooth, depending on your phone type
- The OBD Fusion smart phone app.

Read this thread to get all the information: https://www.e46fanatics.com/threads/obd-fusion.1240733/#post-18380161

Loading the logs into www.DataZap.me and posting the links to the charts here is the best way to share them.

By the way, the surging cold idle you have is generally caused by a vacuum leak somewhere.

 

[rmoconnor41]

Rather than ask a 1,000 questions, can I get you to run a few data logs and post links to the logs here. I do a lot of analysis on the logs and can generally find the problem.

You will need:
- An OBD adapter, either WIFI or Bluetooth, depending on your phone type
- The OBD Fusion smart phone app.

Read this thread to get all the information: https://www.e46fanatics.com/threads/obd-fusion.1240733/#post-18380161

Loading the logs into www.DataZap.me and posting the links to the charts here is the best way to share them.

By the way, the surging cold idle you have is generally caused by a vacuum leak somewhere.

Thanks. Air leaks were hunted down a while back. So we are air tight.

 

[rmoconnor41]

What is that clunk every time the revs drop.

What is the mileage? Does it dissappear completely when warm?

Is it an m52tu? Double vanos.

It may be the vanos seals. Idle instability is one of the symptoms

I was even wondering if it was the ECT sensor

 

[rmoconnor41]

What is that clunk every time the revs drop.

What is the mileage? Does it dissappear completely when warm?

Is it an m52tu? Double vanos.

It may be the vanos seals. Idle instability is one of the symptoms

It has been suggested that it could be the pre cat O2 sensors

 

[NZ00Z3]

Run the data logs and we'll do an evidence based diagnostic.

 

[rmoconnor41]

Run the data logs and we'll do an evidence based diagnostic.

Morning. The specialist suspects the PCV from the noise the engine makes if the oil filler cap is removed when the engine is running and some general air noises somewhere low down in the compartment.

 

[ExMX5owner]

Snippet off the net
A noisy Idle Air Control (IAC) valve, often described as a humming, buzzing, or clicking sound, can indicate a problem with the valve's function, potentially leading to issues like fluctuating idle, hard starting, or stalling.

Had a similar issue with mine hunting like that when I first got it, but I did that, the DISA, and found a vac leak all at the same time, so I,m still unsure of which one was causing it or even if all were contributing.. But the problem disappeared...

 

[rmoconnor41]

Run the data logs and we'll do an evidence based diagnostic.

Snippet off the net
A noisy Idle Air Control (IAC) valve, often described as a humming, buzzing, or clicking sound, can indicate a problem with the valve's function, potentially leading to issues like fluctuating idle, hard starting, or stalling.

Had a similar issue with mine hunting like that when I first got it, but I did that, the DISA, and found a vac leak all at the same time, so I,m still unsure of which one was causing it or even if all were contributing.. But the problem disappeared...

tthanks. We

Snippet off the net
A noisy Idle Air Control (IAC) valve, often described as a humming, buzzing, or clicking sound, can indicate a problem with the valve's function, potentially leading to issues like fluctuating idle, hard starting, or stalling.

Had a similar issue with mine hunting like that when I first got it, but I did that, the DISA, and found a vac leak all at the same time, so I,m still unsure of which one was causing it or even if all were contributing.. But the problem disappeared...

- YouTube

Enjoy the videos and music that you love, upload original content and share it all with friends, family and the world on YouTube.

youtube.com

 

[rmoconnor41]

What is that clunk every time the revs drop.

What is the mileage? Does it dissappear completely when warm?

Is it an m52tu? Double vanos.

It may be the vanos seals. Idle instability is one of the symptoms

- YouTube

Enjoy the videos and music that you love, upload original content and share it all with friends, family and the world on YouTube.

youtube.com