Stock 2005 JCW engine pinging high rpm
 

Hi All,

I recently purchased a beautiful one owner full service history 2005 JCW, I have been thoroughly enjoying the car however an inevitable issue has come up.

A bit of background:

The car was low on power, seem to really die off at high rpm and there was pinging now and then. I had codes read and my post cat O2 sensor was stuck lean. Apparently this was due to the decat (the car was bought like this). So the car was taken in today and software was written to fool the post cat O2 sensor.

The car now feels a lot better, power delivery is much more instant and theres more torque. However there is now serious pinging at higher rpm I am petrified of driving the car. I have ordered an OBD reader so when that arrives i will do some live data logging but so far. At 2000rpm (or lower) I can put my foot down flat and there is no pinging, at about 3400/3500 rpm the pinging starts. I can lightly rev the car out with minimal load and no pinging. What I have noticed is with gradual acceleration (before pinging occurs)power delivery is not smooth, the car subtly judders.

Where should I start and what could the cause of this be? Timing chain/tensioner? Would a bad harmonic balancer cause this?

Direction or those with similar experiences, help is greatly appreciated.

I hope you're using the highest octane fuel you can find.
Although my '02 doesn't ping, I can tell the difference between 93 & the odd occasion I have to use 89 octane.
(I suppose you could try av-gas, but it's $10 a gallon around here!).

We only have 95 octane here so I can rule that out i think

If you're in the UK the ratings are a bit different.
UK95 = US91 +/- which we call a mid-grade. Can you find anything higher? Shell V-power has a good reputation, though I've never tried it.
I'll just comment that full throttle at low (2,000) rpm is liable to encourage pinging. Maybe you could wind it up a bit!

I'm in Cape Town, South Africa. I only tried at low rpm as this should generally be where pinging occurs if timing is out. At least this was the case with my 91 MR2 but i usually don't do that haha

I agree, I have only been doing this to test where the pinging occurs. I pulled OBD codes and have P2270, would this be a cause of pinging? I was under the impression the O2 sensor only comes into play during closed loop.

What he said. Have you "read" the plugs yet? Lean? Proper heat range? Can you try to find an air leak with a judicious squirt or two of starting ether in the engine compartment? A rise in RPM means an air leak of unmetered air.

I should've updated this earlier. Long story short the problem was solved temporarily, then came back.

I have read the plugs and they do seem to be running lean. I sent the car to a tuning shop which I have heard good feedback from. Personally I have never trusted any tunes in South Africa because there is simply no market for it and any 'tunes' are mostly canned tunes, my fears were correct. After thousands spent on back and forth I had a 'custom' tune done. Car seemed fine for a bit then the pinging came back. Its an extremely hot climate here. Temperatures range from 30c(86f ) to 40c (104f) consistently. The car would ping under any form of load above 3000rpm in temperatures above 15c (59f), rendering it unusable. So the car has been parked until now.

After revisiting the forum I have reached out to 'adriancl' who has helped many on here with tuning issues. Fingers crossed he can fix whatever disaster these tuners have caused. I'll update once I have more progress