Quote:
Originally Posted by Megabrode
Lately I've had occasional pinging (pre-detonation, valve clatter, whatever). It's intermittent, on sudden acceleration, in 3rd or above, at 2500-3500 rpm, especially uphill. The sound is a quick or (uphill) an extended "zzzzt," the classic marbles in a can. Pinging can of course cause engine damage.
The history:
- I only hear it with the windows open.
- I thought it was bad gas (Shell). Tried a tank of Sunoco. No change.
- I called Dinan (I've got their engine software). The tech said he hasn't heard of this problem and suggested octane booster.
- Put in a can and the pinging stopped.
- I passed on the dealer's suggestion: $300 to reinstall OEM software and diagnose.
- My friend at an indy shop ran a freebee code check (still with Dinan) using a dealer-quality tester: zero fault codes of any kind.
- Went through the boosted gas. Next tank: the ping is back.
The only relevant M3post thread I could find is here, posts 42 and 49:
http://www.m3post.com/forums/showthr...OzCraig&page=3
Two members (Aviato and OzCraig) fixed what seems like the same problem by replacing the low fuel pressure sensor. But they had related fault codes.
Other possibly relevant notes: - It's hard to believe it's bad gas. I've run Florida 93 octane with no issues since I've had the car, and California guys have no issue with 91.
- I've had the irratic idle some here complain about. Two or three times the engine has died at a stoplight.
Given all that, what do you think may be the problem, and what's a possible fix? Should I just go ahead and replace the LFPS, even with zero fault codes?
Thanks for your thoughts,
Craig (AKA Megabrode) |
Not sure if I was getting the same sound, but more of a mechanical tin sound (maybe more valve noise)...........no effect on performance and chalked it up to valve noise. But this noise was consistently there when I was using Shell gas (we are 91 octane here in CA unfortunately).
In any event, switched to Chevron while back and do not hear the noise anymore. Did try Shell again briefly and noticed the same noise. So could be noisy injectors which are getting a bit cleaned up when using Chevron with Techron?