[CU2] Does your car have an issue with a "post-combustion detonation sound"?

Can someone who is currently using 98 RON and has pinging, do a test by running a full tank of 95 RON?

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Originally Posted by SteveH

That sounds exactly the same as mine now. I only started to hear something around the 5,000 k mark. (Mine is a manual by the way) Mine sounds like a metallic rattle, almost like a cam chain rattling or something. (I know thats not what the noise is, just trying to describe the sound)

I found that my car was worse for both economy and rattling noise when I used Etahnol blended 95 octane petrol

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Ethanol is a not a good mix with the CU2, so I'm told. In any event it is a false economy any saving is more than eaten away by the drop in economy. As I said before I'm sticking to the 95 octane. Sydney to Albury on 98 Octane 8.9 L/100k. Albury to Sydney, same driving conditions, 95 octane, 8.8 L/100k and no pinging!

My CU2 has pinged consistently on 95 RON and 98 RON. Have tried full tanks of both - can't discern much difference in the pinging, it's there regardless of fuel type.

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Originally Posted by bk212

My CU2 has pinged consistently on 95 RON and 98 RON. Have tried full tanks of both - can't discern much difference in the pinging, it's there regardless of fuel type.

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Thanks. Now.... is anyone game to try 100 RON? It is expensive though.

I know ppl who has tried both 95 and 98 (at diff time) has combustion (aka pinging)problem. I want to know if anyone using 98 from the begining (except the fuel from dealer) has this problem as well?

Well I run 98 ron, and I no longer have the "noise", actually, I have traced my noise to loose exhaust bolts, that I tightened myself and used aviation grade temp resitant locktite on...seems to not have come back. Maybe some others have this problem and NOT the post ignition issue???

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Originally Posted by Bobjones

...Maybe some others have this problem and NOT the post ignition issue???

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Now, that would be funny :p

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Originally Posted by Bobjones

Well I run 98 ron, and I no longer have the "noise", actually, I have traced my noise to loose exhaust bolts, that I tightened myself and used aviation grade temp resitant locktite on...seems to not have come back. Maybe some others have this problem and NOT the post ignition issue???

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Fantastic. :thumbsup: Did you notice any specific bolts were loose, such as header bolts, or did you just tighten them all (headers, cat, muffler)? I'll take a look at mine on the weekend.

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Originally Posted by Bobjones

Well I run 98 ron, and I no longer have the "noise", actually, I have traced my noise to loose exhaust bolts, that I tightened myself and used aviation grade temp resitant locktite on...seems to not have come back. Maybe some others have this problem and NOT the post ignition issue???

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Yeah, the kind of sounds a loose bolt would make is what i have... was it an obvious looselness? I too would like to know which bolts it was. If you could let us know it would be appreciated...

I tightened everything, including heat sheilds, there is no "header" bolts as such as the exhaust manifold is cast into the head. I just went to town with the loctite...

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Originally Posted by Bobjones

I tightened everything, including heat sheilds, there is no "header" bolts as such as the exhaust manifold is cast into the head. I just went to town with the loctite...

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Did you check the spring loaded bolts between the header and the 2 cats?

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Originally Posted by aaronng

Did you check the spring loaded bolts between the header and the 2 cats?

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Yes, they were still tight, however I did remove them and loctite them to. I am merely suggesting that people give it a go, seems that most "dealers" and their "technicians" will only find a fault if the computer tells them its there...