Pinging perhaps?

[OzCraig]

Hi guys,

So, I have noticed more and more what sounds like pinging happening from the car. I have run various 95 and 98 brands and no real difference is noticeable.
It happens mainly below 3k and is only in short 4 or 5 'tink' bursts.
I have done the whole free rev in neutral (hold, free rev, 2.k+, etc) and don't hear anything so it's only under load it's happening.
Now of course the dreaded rod bearings creep into one's paranoia but being that the sound is intermittent and load related I'm not sure that's what it is.
I will attempt to get some decent audio of the sound if possible but, this video sounds exactly like what I get but the video is quite short so ear-blink and you'll miss it.

Now I'm definitely no master mechanic but I'm not a totally newby either (I have pulled down and built engines, think EJ Subaru donks), so I thought I'd ask the brains trust here, does that video sound like pinging to you or am I chasing a heat shield or something else rattling?

Thoughts?

Cheers,
Craig

[JsL]

That sounds like engine knock in the 1st second of the video.

Have you changed your spark plugs lately?

Go up a hill with the windows down and see if the problem is worse.

[OzCraig]

Hey,

Thanks for the reply!
Yeah I'm leaning (no pun intended...) towards knock/ping/pre-det at the moment too.
According to the service manual they were replaced about 20,000 kms ago. Mind you, if I got a bad batch of fuel/contaminate that could screw them up too.
It happens at lowers revs (mostly below 4k) and under part to full throttle regardless of incline or decline. It's all about load it appears.
Thanks for the input mate, it helps me confirm that I need to pull the plugs and inspect them for damage, wear, etc.

I was just falling in to that pit of bearing despair everyone goes on about

[OzCraig]

UPDATE - My memory failed me... I thought the plugs were done 20k ago but I am wrong. They were changed at 49631km and the car now has 91000k. Conflate 41k with the car doing quite a lot of shorter trips of late and they are possibly ready to be done.

[DaveDee]

Originally Posted by OzCraig

UPDATE - My memory failed me... I thought the plugs were done 20k ago but I am wrong. They were changed at 49631km and the car now has 91000k. Conflate 41k with the car doing quite a lot of shorter trips of late and they are possibly ready to be done.

Remember the coil packs and plugs form the knock sensors so it's vital to have those spot on. 50K is too far between changes

[sct911]

would you recommend changing coils? had my spark plugs changed last month, which were around 40k old.

would pinging change the sound of the exhaust note?

[OzCraig]

Originally Posted by DaveDee

Remember the coil packs and plugs form the knock sensors so it's vital to have those spot on. 50K is too far between changes

Copy that.
Yeah the more research I do on these engines the more I'm finding that BMW's 100k interval is ludicrous. Seems most people are changing them out at circa 35-40k.
Plugs ordered, now to find a day that isn't 40 bloody degrees to do it in now.

[DaveDee]

Originally Posted by sct911

would you recommend changing coils? had my spark plugs changed last month, which were around 40k old.


would pinging change the sound of the exhaust note?

Pinging is more like the sound of marbles rattling from the engine itself and is very distinct, so any change to the exhaust pitch would be overtaken by that rattling sound.

Generally if the coil packs are playing up you will get codes thrown, so as long as the plugs are in good order there should not be a problem. In a SC car I'd be changing the plugs at not more than 25-30K

[OzCraig]

A bit of feedback for others that are chasing plugs:
I ordered mine through sparesbox's ebay site and they arrived the next day!
Quite a reasonable price and fast delivery.
I recommend them as an option

Cheers,
Craig

[OzCraig]

Gave myself an early mark today and came home to do the plugs.
Seriously guys, it is NOT the mega job from hell that it is made out to be. From pulling the bonnet latch to popping it closed again was 1 hour and 28 minutes. Next time it will be less again now I found a few little tricks.

Anywho, plugs all looked the same so if 1 cylinder is stuffed then they all must be
A bit of oil on the threads but nothing too alarming or unexpected with the high compression.
Good news is Frau Blucher no longer pings! Win.
So to anyone else with plugs circa 40k that is getting some knock I'd say throw some plugs in and see how you go


Cheers,
Craig