VZ Monaro Pinging! Common causes?

[harey]

Hi All,

My old man's black VZ Monaro ls1 m6 has developed pinging in all gears with WOT. Just cruising around and its fine. But plant it and you can hear it ping every time. It still seems to make power but obviously is not a good thing!

It is 100% standard apart from a Mail Order tune from a sponsor of this forum. This was fitted over a year ago and the improvement was massive! So much smoother torque all the way through, particularly in the mid range. Not to mention the improvement in fuel economy.

When the pinging developed over the past month I immediately thought it must be the tune. But the car has been running really well for the past 12 months with the tune. The tuner suggests that the tune has less timing than standard so does not think it is the tune causing the problem.

My old man is not keen to spend any money on the car so I am wondering if there are any common causes of this?

My thoughts were it might be leaning out due to a fuel issue, so I was trying to take it down to a shop for him and get an afr analysis done on a dyno.

Any ideas much appreciated!

[Peter B - CV8]

Might be a bad batch of fuel. Where did he fill up last & was it 98 octane (I'm assuming his tuner calibrated everything for 98 octane).

[Wonky]

Poor fuel is the most obvious culprit. Try changing to a different service station, preferably a busy one on a main road to see if it makes any difference.

In the meantime drive the car in a manner that doesn't allow it to ping as it has potential to cause serious damage!

[VX2VESS]

try a bottle of octane booster until its cleared

[harey]

Ok thanks guys, will give that a shot.

[VX8255]

Partially blocked fuel filter, or a fuel pump on the way out, also possible.

[macjeffrey]

I believe collapsed cats and other exhaust blockages can also be a contributor. Was the fuel filter changed recently? Perhaps a dirty or blocked intake or filter can casue it too. Mostly stuff you can change or check yourself to prevent spending any $

[harey]

Would I be correct in saying that a bad batch of fuel would register as roughly normal air fuel ratio (simply just too much timing for the octane of fuel)? Where as any fuel supply problem would register as a lean air fuel ratio?

[max350]

I have a similar issue with my Monaro. It has a tune as well and sounds like it is pinging, but I went back to the tuner and we plugged his computer in and went for a drive. We heard the pinging sound but nothing was registering on the computer as a ping. Still dont know what the problem is, but he says definetly not pinging.

[harey]

Wow so it is happening to someone else! Thanks for replying. Its weird it still makes good power and drives ok. Just makes a very scary noise.

Did you check the afr's with the tuner?

[VZSSTT]

It still will make good power mate, from what i believe if the computer detects knock it will resort to the low octane table and have less timing again, If it doesnt detect anything it will just pull normally and ping its head off :) Pinging is Not good and spending the money now is going to outweigh repairing a blown up engine later :) btw i have seen mail orders in the past running lean and alot of timing.... it would depend on tuner.

[harey]

Yeah I understand that but why the sudden change? Its been running sweet for a year without one hint of a ping and now it starts quite loudly in all gears at WOT.

Surely something has changed.

[HRT 8]

Yeah I understand that but why the sudden change? Its been running sweet for a year without one hint of a ping and now it starts quite loudly in all gears at WOT.

Surely something has changed.
Harey do the obvious stuff first before you stress.
Check where the fuel came from and add some Octane booster to see if that cures or helps the problem. If it does then bad fuel is your culrpit.
If it doesnt then dig a little deeper with a dyno analysis etc.

[Toddler78]

clean the throttle body/check how oily it is from the PCV hose.
Oil reduces the octane of fuel.

[macca33]

I've had some localised pinging in the past week - BP Ultimate fill. It hasn't happened before and I'm not running heaps of timing, so it was most likely fuel.

cheers

[Avalanche]

clean the throttle body/check how oily it is from the PCV hose.
Oil reduces the octane of fuel.

Toddler78 is right , it can build up over time. The avalanche did the same, Sonny checked the tune etc & it turned out to be oil from the breather system. Cleaned the manifold for me & all has been good since. Also i have been running the Mainlube fuell additive as well ever since. That was a fair while ago & i have not had the issue return. The Mainlube oil additive works well too. :bow: