My 5.7 is detonating (pinging) on low RPM.

[Aussie300]

Over the past couple of weeks my 5.7 (stock apart from Mopar CAI) has been suffering from detonation on low throttle. I have run BP Premium unleaded in this beastie since I bought it apart from a couple of tanks of 91 when I was being a tight arse. It started detonating on 95 ron, so I bumped it to 98 and I reckon it is getting worse. Any light throttle and the rattle is bad enough for me to be very concerned.

Anybody else had this problem? I am off to the dealers next week to get it investigated, but was really curious to see if anyone else's 5.7's have suffered from this.

[MR 225]

My engine has not missed a beat to date. Sorry!

[Hemi57]

I have never heard of this, other that when the Superchips box came out it didn't have a tune which suited the Aussie fuels.

Something is not right in the ECU or sensors. You should be able to swap between any RON fuel and the ECU will adapt after a while.

[Kelvin]

Originally Posted by Aussie300

Any light throttle and the rattle is bad enough for me to be very concerned.

Anybody else had this problem? I am off to the dealers next week to get it investigated, but was really curious to see if anyone else's 5.7's have suffered from this.

It sure is quite serious if driven for too long a period. Light throttle detonation as opposed to heavy load (wide opn throttle) can be caused by the EGR valve or its electronically controlled management system. However, I'm quite confident that your dealer will quickly solve this issue. There really are several things that can cause this problem. The wonderful scan tool in the right hands will discover the villan.

[joey]

What Kelvin said. The EGR is a likely cause.
If you have the Predator you could temporarily disable the EGR to see if that is the cause of the noise.

[Aussie300]

No Predator. Thanks for the input guys. I know how serious detonation is in a car. I have a turbo car too, that runs 9.1-1 compression.

I will get it checfked at the dealer and drive as little as possible until I get there.

Cheers

[Kelvin]

Good luck and keep us informed.

[V8300]

Kazz, I actually had the same issue about a month ago. It was a hot day and had refuelled in the morning (BP Ult). I don't know that much about it but perhaps a bad batch (low octane) fuel? Mine seemed to clear itself over a day or 2.

[Aussie300]

Originally Posted by V8300

Kazz, I actually had the same issue about a month ago. It was a hot day and had refuelled in the morning (BP Ult). I don't know that much about it but perhaps a bad batch (low octane) fuel? Mine seemed to clear itself over a day or 2.

I thought mine might have been fuel too, but it has been going for around 4 tanks of fuel now. Even put octane boost in yesterday, after filling with 98 and still got the issue. It's not as bad though. Rang the dealer, and their best Chrysler mechanic is on holidays, so they asked me to bring it in week after next. They didn't seem to think the problem was too dramatic, but after seeing what detonation does to pistons in Turbo cars, I am not too keen to drive it much.

[ricmcm]

Sorry to hear about your grief Kazz,
you will have drive one of your other beasts!
Richard