Sounding a bit like an old VW beetle - how to diagnose?

[jvanzyl]

So driving today, I noticed at some point in the journey that the exhaust note changed... It now sounds like an old VW beetle (kind of).. and there is excessive vibration from the engine.

Does anyone know what area within the ECU Master log I can look at to start trying to diagnose?

https://1drv.ms/f/c/60aca0059167de5b/EjSmQCIOTKFFqZ22naZTib4BmUq7cMsemIouRX8RiVp1LA?e=9JBvmq

The above folder holds the log files from today - I have also included a video so you can hear the sort of boxer burble it's got. I welcome any feedback or directions.

[Carolyn]

That doesn't sound good.

[jvanzyl]

That doesn't sound good.

thanks.. done some initial analysis/poking around and what I can observe is the following:

Upon firing it up, post the 2 min mark it starts going very lean and the RPM is lower than it is normally.
I'm currently leaning towards some kind of fuel issue which is resulting in a cylinder not firing, which I "think" lends itself to a lower RPM and a vibration in the engine when revving.. dunno..

[Kurt]

It sounds like it's down at least one cylinder to me. I can't help with the logs, but as a basic test I'd try starting it up and unplugging/pulling out one coil pack at a time, noting when the engines tone changes (or it stalls completely), this will help you narrow down which cylinders aren't firing

[Carolyn]

It sounds like it's down at least one cylinder to me. I can't help with the logs, but as a basic test I'd try starting it up and unplugging/pulling out one coil pack at a time, noting when the engines tone changes (or it stalls completely), this will help you narrow down which cylinders aren't firing

Yes.  And, given the lean reading, possibly a bad injector.

[jvanzyl]

It sounds like it's down at least one cylinder to me. I can't help with the logs, but as a basic test I'd try starting it up and unplugging/pulling out one coil pack at a time, noting when the engines tone changes (or it stalls completely), this will help you narrow down which cylinders aren't firing

Excellent observation. So weird thing is, when I started investigating a "lower than I'd like" battery reading (see other thread), I started unplugging stuff like the power steering pump and a step down converter for the dash cam.

 Weird thing is the following morning after unplugging this stuff,  my wife took the car to work and I noticed that it sort of stalled when trying to pull away from cold.. thought it was a bit weird and she said she felt like she had to rev it a lot more than usual, and now in hindsight I'd say it was uncharacteristically down on torque in the very low revs. This stalling will happen when turning on from cold and trying to ease back gentle on a level surface out of the garage..

Yes.  And, given the lean reading, possibly a bad injector.

So... I guess the easy way to identify the cylinder is to unplug the coil packs and find the one that doesn't change the engine note. I need to try and find another injector to swap it out to.

Anyone got any old siemens deka 630's kicking about?? 

[jvanzyl]

Progress update.
I've identified the problem cylinder.



I unplugged each injector one at a time and there was no change to the engine when I got to that one.

So..  what's the "smart" thing to do? Swap the injectors over to another cylinder and track the problem to it?

Or is there no point (given lean readings) and it's a case of just replacing the injector in which case do you replace one or do them in a set?

[Ardent]

Fairly sure another member had an injector issue and the general advice was. Just the one.

[jvanzyl]

Fairly sure another member had an injector issue and the general advice was. Just the one.

Interesting.. OK. Seems there's a fair bit of info on "flow matched to 2%"... erm.. not sure!