Pinging mystery

[MINIDCT]

Fixed

[m3jala]

Originally Posted by GYY95M3

Hmm, this thread seems to have gone a bit quiet, so I'll just add some more of my experience (bear in mind that my car is currently still under a BMW factory warranty)

Earlier this year the BMW shop did a compression test and, after comparing it with another car, declared compression was too high due to carbon build up.

[IMG]https://pbs.twimg.com/media/Dez6UGeVQAAsCqI.jpg[/IMG]

Plausible I suppose, although no explanation was forthcoming as to why a compression recorded as 150% of specification, why carbon buildup should occur in an engine run on the correct octane fuel nor the wisdom of comparing my car with another car 5 years older with unknown milelage/usage (to me).

Although I was sceptical about the readings and conclusion, they went ahead and did a carbon clean anyway... guess what... absolutely zero improvement, not even after a 4,000km road trip in the last couple of weeks.

Ha! So what do you all think about that..?

I have had these type of issues on my old 330 CI (with 100k miles) which I daily drove on short sprints around the city. It always acted up in the summer (or I heard it more due to windows rolled down). I gave up trying to fix it thinking it was due to age. One time I took a long distance highway trip which I suppose cleaned the car out as it was running real smooth right after that trip. I think what you all are describing is somehow related. Carbon buildup, computer learning, clean air filter, clean spark plugs, etc. I figure when in doubt take it on a weekly highway spin at temperature and that should keep it cleaned out. Try maybe it helps

[MINIDCT]

My M3 isn't a daily driver because, 2-3 short trips about town each week (mostly to the BMW shop these days), then off on long trips to the beach or ski fields. I don't drive like Grandma, although I don't drive like an idiot either... you'd get locked up pretty quick around here!

[Megabrode]

Status report: My pinging disappeared three weeks ago after some serious backroad flogging. I get that correlation is not causation, but that fact may indicate carbon build-up, possibly due to several long trips I took while nursing the throttle for gas mileage (averaged 24.2). Meanwhile, I expect to feel no more anxiety about this former problem unless and until it returns.

[MINIDCT]

Don't hold your breath..!

[jeremism]

I have had an issue with pinging on a 2011 e92 M3 with 45000kms, easily reproduced loading up the car in 3rd or 4th around 2k rpm. Have done a fair bit of reading on this forum and others about pinging. A good 200km blast in the hills didn't help the issue.

I'm now halfway through my second bottle/tank of Redline SI-1 fuel system cleaner (after researching it vs Techron vs BMW's rebadged Techron).

I've observed that as I got to the end of the first bottle, pinging had definitely reduced. At this point I've not observed any pinging at all in the last two drives while attempting to reproduce it. Might be worth a go.

[mharris2007]

Try changing the spark plugs.

[MINIDCT]

Watch this space...

[Megabrode]

GYY95M3, have you tried replacing the low-pressure fuel sensor? Part # 13537622231

[MINIDCT]

Originally Posted by Megabrode

GYY95M3, have you tried replacing the low-pressure fuel sensor? Part # 13537622231

As far as I'm aware the BMW Techs have never replaced such a part.

[kimiraikkonen]

Originally Posted by GYY95M3

Gotta straighten that one out.

BMW dealer workshop changed plugs (even though existing plugs were only 10000km) and igniters out from the 2008 car mentioned above in the compression test. They confirmed that that was a total waste of time with a test drive, no improvement whatsoever. Even put their own fuel in it at one stage.

Previously they had put through two doses of the BMW fuel conditioner and ran it for 600km, again negligible effect. The engine started banging away within a week and got significantly worse after a couple of 2000km trips.

Oil is another red herring, it's perfect and only been in 4000km. Took the precaution of getting the filter and an oil sample, although I'm not totally convinced it actually came from my car.

Believe me, every Tech master in the local BMW dealer workshop has scratched their heads over this one, and still no resolution. I'm sceptical anyone outside BMW would have enough knowledge to identify the problem, while I'm beginning to wonder if in fact the BMW techs do. They should put it on a Dyno, which would confirm whether any pinking is going on in about 5 minutes flat, but they haven't got one.

Again, I should point out that this is a car I bought off the showroom floor with full warranty for 3+2 years, there is no question it has never been mistreated, raced, crashed or modified in any way.

Today I dropped the problem on the desk of the Managing Director at BMW NZ.

Watch this space...

How are your engine mounts? Once they start to go and get compressed, you will get rattling during upshifts and downshifts.

[MINIDCT]

Nope!

[kimiraikkonen]

Originally Posted by GYY95M3

Now that is almost telepathic you mention that kimiraikkonen.

The other day waiting at the lights I can feel this almost imperceptible shudder at idle, drop it into neutral, it's still there. I think to myself, hmm, that feels like an engine mount on the way out..!

Relationship to pinking, which I'm not convinced it's doing anyway, would certainly be rather tenuous. Interested to know what you think might be making the noise if an engine mount was stuffed.

Car is booked for annual service on Friday 15th next week and I was going to ask the BMW Tech to check them... let's see if what comes of that.

If that's the problem, I'll be gobsmacked..!

My mounts are starting to go.....but the buzzing sound is very infrequent and when the sound is there, if I just blip the throttle a bit (like +500 rpm) it goes away. So I think the sound comes and goes depending on how the engine block is settling back into the mounts after coming off the revs.

Will do the engine mounts when I do my RBs in the future. At 120K mi. now (knock on wood). Let me know what you find the next time it's on the lift.

[Shiza]

Tbh at 154k I’d say that my engine mounts are due to be replaced lol, i’ll swap them out and report back as to wether it fixes the issue.

[m3peat]

For reference, I have this pinging and have new plugs, new bearings, newest software, new motor mounts and use top tier premium gas (usually shell) with an OEM Mod stock exhaust. I also replaced all fluids and filters within 10k miles (oil changed 3 times during that period).
I am curious about the low pressure fuel sensor (LPFS) mentioned above and will look for others who have replaced it to see what that fixes/cures.

Found a discussion which some posts sounds similar and some don't but one poster replaced the LPFS and it solved the noise for him. See here, later in the thread:

http://www.m3post.com/forums/showthr...re+fuel+sensor

Best part is he said it was a 30 minute job and cleared the noise and smoother idle.

[Megabrode]

Originally Posted by m3peat

For reference, I have this pinging and have new plugs, new bearings, newest software, new motor mounts and use top tier premium gas (usually shell) with an OEM Mod stock exhaust. I also replaced all fluids and filters within 10k miles (oil changed 3 times during that period).
I am curious about the low pressure fuel sensor (LPFS) mentioned above and will look for others who have replaced it to see what that fixes/cures.

Found a discussion which some posts sounds similar and some don't but one poster replaced the LPFS and it solved the noise for him. See here, later in the thread:

http://www.m3post.com/forums/showthr...re+fuel+sensor

Best part is he said it was a 30 minute job and cleared the noise and smoother idle.

That's the thread I alluded to earlier in this discussion. It's a cheap part: https://www.amazon.com/Bosch-Origina...ds=13537622231

If my ping returns, I'll try replacing the LPFS.

[MINIDCT]

Sorry to disappoint you chaps but....

Low Pressure Fuel Valve - Checked & Tested A Ok
Engine Mounts - Inspected, they're perfect

[ItsGary]

Originally Posted by Megabrode

That's the thread I alluded to earlier in this discussion. It's a cheap part: https://www.amazon.com/Bosch-Origina...ds=13537622231

If my ping returns, I'll try replacing the LPFS.

theres a difference between the LPFS and the normal fuel sensor btw. I couldn't find an OEM Equivalent to the LPFS only the normal one and its bosch.

[Megabrode]

Originally Posted by ItsGary

theres a difference between the LPFS and the normal fuel sensor btw. I couldn't find an OEM Equivalent to the LPFS only the normal one and its bosch.

Thanks. I'll keep this in mind if my pinging returns.

[Shiza]

Just replaced my spark plugs and coil packs, no difference with the pinging. I’ve had this for about 60k miles. It’s gotta be something simple that we are overlooking.

[Cwleo]

I have changed the following but i can still catch the slight pinging/rattle (with the windows down). Note that i didnt change the items of the pinging/rattle but the usual wear and tear replacement ...

1) conrod bearing
2) top valve covers and gasket
3) spark plugs
4) tried octane boosters to 100ron
5) decarboniser (using gas type)
5) flogging the car (although it seems to help abit but it comes back)

Noticed that the pinging is more prevalent during hot days. Is there any possibility that the pinging/rattle is coming from the gearbox/clutch rather than the engine?

[ItsGary]

Originally Posted by Cwleo

I have changed the following but i can still catch the slight pinging/rattle (with the windows down). Note that i didnt change the items of the pinging/rattle but the usual wear and tear replacement ...

1) conrod bearing
2) top valve covers and gasket
3) spark plugs
4) tried octane boosters to 100ron
5) decarboniser (using gas type)
5) flogging the car (although it seems to help abit but it comes back)

Noticed that the pinging is more prevalent during hot days. Is there any possibility that the pinging/rattle is coming from the gearbox/clutch rather than the engine?

Strange, for me this rattlesnake type rattle only happens during colder weather.