- Jan 14, 2018
- Reaction score
- The Seasonally Frozen Wastelands
I would not have described "ping" or "detonation" as sounding like a cricket chirp. But if more octane makes the noise go away, that's probably what it is.I’ve been running 93 octane, seems to get rid of a ping (sounds like cricket chirp) when under load accelerating, and gets way better fuel mileage. I’ve read this could be egr (which I know nothing about),
Detonation ("pinging") and a malfunctioning EGR system go hand-in-hand. If the V-6 EGR valve is like the one on my '88 5.7L (Negative backpressure sensing, has an "N" near the part number stamped into the top) it should hold vacuum when tested. If it leaks vacuum, it's defective. If it's seized, it's defective. Sometimes they can be cleaned, sometimes they have to be replaced. If you manually lift the diaphram/pintle at idle, the engine should stumble. Let go of the diaphragm/pintle, and the engine idle should recover and become smooth. If the idle doesn't degrade with the pintle lifted, the exhaust passages in the intake manifold are plugged with carbon, which will have to be chipped- or solvented-out
The EGR vacuum system needs to be checked as well.
I'm no fan of "gimmick" spark plugs, but scrapping them is not the first thing I'd do.or it could be wrong spark plug?? I’m running e3 diamond fire just to try.
Verify EGR as already discussed.
Connect a scan tool, verify ALL the sensors and computer outputs, in particular the knock sensor and ignition advance/retard. If you tap on the cylinder head with a small hammer to simulate detonation, the timing should retard which you'll notice as a reduction--and then recovery--of the idle speed. Initial timing is not adjustable, but if the knock sensor, sensor wiring, or the electronic spark advance/retard isn't working right, the ignition timing could be way "off".
87 octane should run just fine in that engine.I filled up with 87 lately to try and save some money but I don’t want to keep doing this if causing issues. Any guidance in troubleshooting would help a ton!
Consider fully-warming the engine, then directing a "urine stream" of water into the throttle body at FAST idle (~2000 rpm or so.) When it's me, I over-do it by using about a gallon of water; and then I have to change oil afterward to get rid of crankcase moisture/contamination. This should "steam-clean" your combustion chambers to eliminate excess carbon that might raise compression or cause combustion-chamber hot spots leading to detonation. Costs almost nothing to try; and using water doesn't make the neighbors call the fire department due to the smoke from products like Seafoam or GM Top Engine Cleaner dumped down the throttle body.
If nothing else is helping, it may be a matter of replacing the plugs with non-gimmick sparkers.Get rid of the gimmicky plugs. Either go with AC Delco R44LTS6 or NGK 3951 spark plugs.
I'm thinking that GM recommends R44LTS6 plugs; but I'd install (C)R44LT instead, to get away from the .060 gap. I have grown to dislike the gigantic plug gaps in any application, but even moreso in high-performance use, or on Vortec applications that seem to commonly have distributor cap failures. But like I said...I think the LTS6 .060 gap is recommended by GM.