Join Date: Sep 2007
Location: Coweta. OK
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7.3 unusual knock - detonation??
Noticed lately (colder mornings) during light acceleration heading out on the road that I can definitely detect an intermittent knocking sound, which sounds to me somewhat like detonation on one or more cylinders. Its not the usual diesel clattering sound, which is more rythmic in nature, but rather more of an intermittent knocking during light acceleraton when the engine is not to full operating temp. Its not as noticeable after the engine is at normal operating temp. but i think I can still here it a little when I accerlerate after stopping or slowing down. It's not noticeable at cruise.
Sure wish I could record and post the sound i'm hearing but I guess my description will have to do.
Any ideas? I've not had it scanned for codes - no CEL/SES indications. 120K miles on it with no other problems, did change the fuel filter but no change. Have been using Power Services for about the last 4 or 5 tanks. Have also noticed a drop in fuel mileage but my driving
habits have not changed.
Injectors going bad? Low fuel pressure?