E92 320d low power and performance logfile analysis

Smoukey · 10-03-2017, 05:20 AM

Hello!

Long story short - the car seemed a little bit down on power so I decided to check its operational parameters. Results are following: acceleration 0-100 km/h: 10.2 s whereas for new car it's 7.7 s.

Logfile #1 shows that turbo boost values differs from target value and turbo spool-up is too slow. On the other hand maximum boost reaches 1.66 bar and matches target value so no problem with that. Fuel pressure good as well - matches target value all the time.

Also - between gears turbo boost drops very fast and it takes a lot of time for turbo to spool-up when accelerating in next gear.

Last week I logged another test drive, (log #2) and the summary is following:

1. Fuel system pressure follows target value all the time - no problems with this.

2. Boost pressure reaches its maximum target value but increases too slowly. At least I assume it's too slowly - please correct me if I'm wrong.

3. Airflow exceeds target value of about +30% when turbo boost reaches or is close to its maximum target value.

Have someone had this problem before? What could be the most likely reason of slow turbo spool and fast boost pressure drop between gears?

Is this pointing to a turbo system pressure leakage? Or sticking/defective turbo actuator? Or defective MAF?

P.S.
I'm planning to perform turbo system pressure leakage test this week.

Thanks!

Regards,

Karlis

e92 320d 177hp N47 engine 2007

Smoukey · 10-04-2017, 03:14 AM

Yesterday performed a pressure leak test for turbo system at 1 bar. No leaks was found.

Checked the turbo actuator and its linkage seemed very loose in side-to-side movement, but seemed OK in vertical movement (actuator actual working direction). By moving with hand, actuator showed only slight resistance which seemed OK. Only I'm not sure about the total necessary travel length of the actuator piston and how to precisely check the actuator in operation.

At the same time found and replaced a damaged vacuum hose at T-connector, but this was not related to the turbo system.

Actually - not sure how the whole vacuum system works for N47 engine and what's the purpose of the vacuum actuator under the EGR cooler. Couldn't find any info regarding this. It would be nice if someone could explain this in detail.

Smoukey · 10-07-2017, 02:40 PM

Engine diagnostics continues - another test drive with data logger:

Anyone has anything to say about this graph?

10-03-2017, 05:20 AM	#1
Smoukey Registered 0 Rep 4 Posts Drives: e92 Join Date: Sep 2017 Location: Europe iTrader: (0)	E92 320d low power and performance logfile analysis Hello! Long story short - the car seemed a little bit down on power so I decided to check its operational parameters. Results are following: acceleration 0-100 km/h: 10.2 s whereas for new car it's 7.7 s. Logfile #1 shows that turbo boost values differs from target value and turbo spool-up is too slow. On the other hand maximum boost reaches 1.66 bar and matches target value so no problem with that. Fuel pressure good as well - matches target value all the time. Also - between gears turbo boost drops very fast and it takes a lot of time for turbo to spool-up when accelerating in next gear. Last week I logged another test drive, (log #2) and the summary is following: 1. Fuel system pressure follows target value all the time - no problems with this. 2. Boost pressure reaches its maximum target value but increases too slowly. At least I assume it's too slowly - please correct me if I'm wrong. 3. Airflow exceeds target value of about +30% when turbo boost reaches or is close to its maximum target value. Have someone had this problem before? What could be the most likely reason of slow turbo spool and fast boost pressure drop between gears? Is this pointing to a turbo system pressure leakage? Or sticking/defective turbo actuator? Or defective MAF? P.S. I'm planning to perform turbo system pressure leakage test this week. Thanks! Regards, Karlis e92 320d 177hp N47 engine 2007
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10-04-2017, 03:14 AM	#2
Smoukey Registered 0 Rep 4 Posts Drives: e92 Join Date: Sep 2017 Location: Europe iTrader: (0)	Update: Pressure leak test Yesterday performed a pressure leak test for turbo system at 1 bar. No leaks was found. Checked the turbo actuator and its linkage seemed very loose in side-to-side movement, but seemed OK in vertical movement (actuator actual working direction). By moving with hand, actuator showed only slight resistance which seemed OK. Only I'm not sure about the total necessary travel length of the actuator piston and how to precisely check the actuator in operation. At the same time found and replaced a damaged vacuum hose at T-connector, but this was not related to the turbo system. Actually - not sure how the whole vacuum system works for N47 engine and what's the purpose of the vacuum actuator under the EGR cooler. Couldn't find any info regarding this. It would be nice if someone could explain this in detail.
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10-07-2017, 02:40 PM	#3
Smoukey Registered 0 Rep 4 Posts Drives: e92 Join Date: Sep 2017 Location: Europe iTrader: (0)	Update: another test drive with data logger Engine diagnostics continues - another test drive with data logger: Anyone has anything to say about this graph?
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