Pinging mystery

ItsGary wrote

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

Status report: My pinging stopped totally in May with no changes except avoiding Shell 93 octane. I've since moved north from FL, so I'm dealing with cold weather. The car loves the dense air, and the engine rattle has not returned. I never determined what caused it in the first place.

Glad to hear its resolved itself. When I first got my car I had a similar issue. The noise was similar to an aluminum extension ladder and the noise the rung locks make as they clack over the rungs as you extend the ladder right after start up and would go away when the car was warmed up. In my case it was most def the gas. I was filling up with 93 at a ma and pa gas station and the quality was clearly poor. Once I switched to exxon or costco gas, it took going through two tanks before it went away in full. I do think some adaption was attempted but my guess is the gas was under 91 octane despite being labeled 93. The fact that octane booster made it go away on your end makes me think it was gas for you too.

Mvy wrote

Glad to hear its resolved itself. When I first got my car I had a similar issue. The noise was similar to an aluminum extension ladder and the noise the rung locks make as they clack over the rungs as you extend the ladder right after start up and would go away when the car was warmed up. In my case it was most def the gas. I was filling up with 93 at a ma and pa gas station and the quality was clearly poor. Once I switched to exxon or costco gas, it took going through two tanks before it went away in full. I do think some adaption was attempted but my guess is the gas was under 91 octane despite being labeled 93. The fact that octane booster made it go away on your end makes me think it was gas for you too.

Yes! Extending an aluminum ladder is exactly the sound!

A tank of bad gas -- from where I don't recall -- was my first theory, and I still think it's the most likely cause. My engine runs super sweet now with any major brand, including Shell.

Based on the experience of others on this thread -- e.g. Cwleo and ItsGary -- I also think there must be multiple causes of the same or similar pinging or rattling noises.

A potentially related note: My last Blackstone report showed an unusually high concentration of lead. My thought -- again a theory -- is it was due to the octane booster that eliminated the rattle. We'll see if there's a change with my next oil change. If it's still present, it may be time to switch out the rod bearings.

Wanted to add some notes here. I started having the pinging as well on acceleration. Car was at 30k, so I did the usual maintenance and then some:

1. Spark plugs
2. Air filter
3. Removed my 93 octane tune back to oem (91) for testing, sure enough, pinging stopped but it's clear that's not the solution as the aftermarket tunes we all know squeeze more out of the car, while the oem tunes try to add some buffer.

Here's what did it for me.
4. Bought Chevron Techron Concentrate Plus and put in 8oz on a full tank.
5. Took the car out for a 5 hour saturday trip.

Sure enough, car runs smooth as butter now. I've had this happen on my backup 330 ci as well which was a commuter car, as well as my wife's VW Touareg. We live close to work and cars heat up but just barely.

Pair this with the shell advice above.

The pinging hasn't returned, and my latest Blackstone wqs clean. By email a Blackstone engineer agreed the high lead reading in my previous report was probably due to the octane booster I'd used once to quiet the pinging: "This looks to be a healthy 4.0L at the time of sampling." I still have the Dinan stage 1 tune. The whole episode -- about a month of pinging -- remains a mystery to me.

pinging can be influenced by fuel octane rating, ambient temp, and ignition timing. had an issue with a shark tuner on my e46 years back. always ran premium, as soon as tune was installed the pinging started, that was the only variable that had changed. recommend going back to stock tune or check out active Autowerke if u are in south Florida...

mapster37 wrote

pinging can be influenced by fuel octane rating, ambient temp, and ignition timing. had an issue with a shark tuner on my e46 years back. always ran premium, as soon as tune was installed the pinging started, that was the only variable that had changed. recommend going back to stock tune or check out active Autowerke if u are in south Florida...

Years ago AA solved the pinging problem on my e36M. Great guys, especially Karl (is he still there?), who did it must have been 15 dyno pulls to get their software right. The car ran sweet after that. I also had their stage 1 software in my e46M, which never pinged during 11 years of ownership. With the e92M I have Dinan stage 1 -- which a Dinan engineer claimed had zero to do with the pinging.

You make a good point about ambient temperature. The e92 pinged in the FL heat and humidity before I moved to VA. No sign of it down here since May of last year. But I still think my problem was a bad tank of Shell 93.

I still have my pinging . I don't think it's related to the brand of gas as I have tried multiple different stations. I should pull my ESS tune off and see if it makes a difference.

I figured out the sound for me I believe.

Driver side exhaust manifold heat shield

ItsGary wrote

I figured out the sound for me I believe.

Driver side exhaust manifold heat shield

huh, now I have to go jiggle my heat shields lol

Shiza wrote

ItsGary wrote

I figured out the sound for me I believe.

Driver side exhaust manifold heat shield

huh, now I have to go jiggle my heat shields lol

Was this the fix??

wfdeacon88 wrote

Was this the fix??

They make a little noise when I jiggle them but I'm not convinced that's my issue. I still need to pull off my tune and see if that makes a difference when I have the time.

wfdeacon88 wrote

Was this the fix??

no clue i havent fixed it yet lol

Solved my issue. One of my throttle body intake boots was crushed allowing unfiltered air into my rear passenger side throttle body. Easy $4 fix.

https://www.ecstuning.com/b-genuine-bmw-parts/intake-boot-priced-each/11617838287/

Shiza wrote

Solved my issue. One of my throttle body intake boots was crushed allowing unfiltered air into my rear passenger side throttle body. Easy $4 fix.

https://www.ecstuning.com/b-genuine-bmw-parts/intake-boot-priced-each/11617838287/

This may explain my pinging as well! As I said, my pinging stopped last year, but when I had my valve cover gaskets replaced recently, the tech said an intake manifold gasket was pinched and replaced it.

Is an "intake manifold gasket" the same thing as a "throttle body intake boot"?

Megabrode wrote

This may explain my pinging as well! As I said, my pinging stopped last year, but when I had my valve cover gaskets replaced recently, the tech said an intake manifold gasket was pinched and replaced it.

Is an "intake manifold gasket" the same thing as a "throttle body intake boot"?

I would assume they are the same thing since people like to call the intake plenum an intake manifold when they don't know what it's called. Even a BMW tech

Shiza, I believe you have solved the pinging mystery, at least in our cases.

Megabrode wrote

Shiza, I believe you have solved the pinging mystery, at least in our cases.

So this is an easy fix? having the same issue

wfdeacon88 wrote

So this is an easy fix? having the same issue

It would not be an easy fix for me. You have to pull off the intake plenum and I don't know what else. Beyond my skills and experience. And there's no guarantee you have exactly the same problem. There seem to be multiple causes of pinging. Seems like it would be something to check out, though.

Mvy wrote

Glad to hear its resolved itself. When I first got my car I had a similar issue. The noise was similar to an aluminum extension ladder and the noise the rung locks make as they clack over the rungs as you extend the ladder right after start up and would go away when the car was warmed up. In my case it was most def the gas. I was filling up with 93 at a ma and pa gas station and the quality was clearly poor. Once I switched to exxon or costco gas, it took going through two tanks before it went away in full. I do think some adaption was attempted but my guess is the gas was under 91 octane despite being labeled 93. The fact that octane booster made it go away on your end makes me think it was gas for you too.

By far the best description of this sound! Holy crap that's amazing! I hear it too sometimes. I've owned my car for 1 year and have heard it 3 times. Usually when it sits for more than 48 hours and runs perfectly fine otherwise.

wfdeacon88 wrote

So this is an easy fix? having the same issue

If you're a DIY kind of guy this is a super easy thing to check and see if it's your issue.

My intake boot was clearly deformed from the constant heat and the plenum being installed incorrectly. One side looked crushed.

Took me 30 min to pull off my plenum and replace my intake boot. The only pain was installing the new boot using the original metal clamp. I found the easiest way was to tighten the clamp around the boot before install and then grease it up. It will slide right on.

Good luck!

UPDATE: After two years, the dreaded pinging returned this month on a 1500-mile trip, 90% cruising on I-95. I took the car to a respected local indy shop, where a tech drove it, heard the ping, and said it was normal. Reassured, I thrashed the car in the Blue Ridge Mtns for 2 hours. The pinging disappeared. I have no idea if, or if so why, steady cruising would cause a ping, and hard use would cure it.