2002 AUIII I6 rattle/clatter under load from passenger side. Is this pinging?

rowan194 · 12-12-2012, 08:35 PM

Kind of a cross between a rattling and clattering (not a consistent ticking like lifters), when taking off in first, or at a more moderate acceleration at the point the auto trans backs off slightly to change up. I can hear it only when the passenger window is open. Doesn't seem to be lagging or hesitating, if I couldn't hear it then I wouldn't even know something was amiss.

No noise at idle, 0% accel, or maintaining speed... only hear it under moderate load. So I don't think it's a bearing?

It does seem to be worse today after I filled up, not sure if it's due to a new batch of fuel or just the hot weather.

Is this pinging or some other common prob? I usually use stock standard unleaded (91), but occasionally fill with premium 98.

Thanks for any help.

rowan194 · 12-12-2012, 11:18 PM

Have looked up some vids of knock/pinging on youtube and some do sound like what I'm hearing.

Still have a less than perfect exhaust (partly blocked) so it could be that the engine is running hotter. Cluster temp and coolant levels are normal.

Or could it be an electrical problem, like a busted knock sensor?

**SSD-85** · 13-12-2012, 08:16 AM

Its possible that its one of your pulleys. But we would need to hear it to know for certain.

rowan194 · 14-12-2012, 08:02 PM

Now that I think about it, I had a similar clattering under load happening years ago in the crappy old JB camira my wife used to have. Trying premium 98 (which was newish at the time) completely stopped the noise and made a noticeable improvement to power.

I'm going to try an octane additive to see if it stops the noise on this particular tank of (91) fuel.

Is it normal for an older engine to suffer from pinging or is there something else I should be looking at? 2002 & 210,000km

mik · 15-12-2012, 01:18 AM

yes i think i would be running a 95 or higher for a while and see how it goes, perhaps even from another servo just in case of dodgey fuel..

Maka · 15-12-2012, 10:53 AM

G'day Rowan, its plausible its pinging because of the blocked exhaust superheating the carbon on top of the pistons, first thing ide do is check your knock sensor is in spec, next is maybe use a topend cleaner to remove carbon deposits and finally, look at getting another exhaust. Its pretty urgent -a burnt exhaust valve is not good.

Obviously its hard to diagnose without hearing it for myself, does it only do it when the engine is labouring? Heres a definitive test- find a decent hill and crawl up it slow, put it into 3rd & foot flat to the floor see what happens, if its pinging you certainly will hear it & be able to repeat it. Good luck & keep us posted!

cheers, Maka

rowan194 · 16-12-2012, 04:15 PM

Quote:

Originally Posted by Maka

G'day Rowan, its plausible its pinging because of the blocked exhaust superheating the carbon on top of the pistons, first thing ide do is check your knock sensor is in spec, next is maybe use a topend cleaner to remove carbon deposits and finally, look at getting another exhaust. Its pretty urgent -a burnt exhaust valve is not good.

Hi Maka, I have a cheap OBDII USB thing I bought off ebay, recommended in another thread here, just have to hook it up. I presume a dodgy knock sensor would throw a code? Also, doesn't a knock sensor simply compensate for a physical problem, ie by reducing power? So fixing the sensor wouldn't stop the underlying problem, just the symptom... but it would still help protect the engine?

For top end cleaning do you mean something like this?

http://www.nulon.com.au/products/Aer...r#.UM1IIGnO_To

Step 3 is piston crown cleaning, via the spark plug holes. I've used this product once before, but didn't see any gunk blowing out of the holes like it does in the video.

Quote:

Originally Posted by Maka

Obviously its hard to diagnose without hearing it for myself, does it only do it when the engine is labouring?

Yep, pretty much. I remember the old Camira used to clatter when labouring just before it kicked down to a lower gear. The AU engine isn't quite as bad, but I do hear it when (eg) accelerating from an 80 to 100 zone on the freeway, without enough pedal to kick it down to 3rd. Releasing the accel slightly stops the noise, then pressing it back to the same spot starts it again.

Maka · 16-12-2012, 06:15 PM

G'day Rowan,

hook the reader up & see what it throws! The knock sensor detects spark knock or ping & it sends a message to the ecu to back off (retard) timing a bit to compensate for poor fuel quality ect. Mik was spot on in his remarks previously imo.

Have a look at the link below for some more info about pinging, knocking & detonation.http://www.supras.org.nz/techinfo/detonation.htm

Have you been using premium fuel lately because that could explain why you didnt get the smoke form using the topend cleaner- the topend was already clean!

Good luck with it hope you solve it asap! Keep us posted mate

cheers, Maka

rowan194 · 16-12-2012, 09:26 PM

There was plenty of smoke from the exhaust once I restarted the engine, just no brown gunk spattering upwards when I was cranking it without the sparks.

I figured that was probably a good thing.

(Will be interesting to see if it's any different this time round.)

The talking hands in this video sound like the guy from Office Space ("Hello Peter, what's happening? Yeaahh, I'm gonna need you to go ahead and come in tomorrow") but it seems to be a pretty good description of how knocking occurs.

http://www.youtube.com/watch?v=WuCUGcqO5SE