Anyone else having alot of spark knock (some folks call it spark rattle, I call it spark knock) at low speed and moderte (not hard) acceleration?

I run 87 gas, but good quality, always exxon.

 

I had that on a '98 4.6 motor.

I unhooked the battery, turned the headlights on, and left it that way for 30 minutes.

Turn the headlights off, reconnect the battery, started it up and drove it about an hour.

I never had that problem again.

Good luck.

 

Your problem is Exxon. They make a really clean gas but it is also one of the absolute lowest in BTU content. Try a different name brand and see the difference. In my neck of the woods Citgo rules followed by Sunoco, Shell & Chevron. Stay away from BP (Amoco) too; they’re iffy at best.

 

Well, Thanks jpdadeo, but I have an Exxon card, so that kinda sux, cuz Exxon, BP and Ammaco are the main stations where I live!! Well I guess I'll just have to start running higher octane.

Speaking of which, does anyone have proof that higher octane gas really improvers gas milage?? I have always heard that, and belived it, but never tried it out??

BTW, stock engine, except for K&N intake. (hope to onday get Xcal 2!)

 

It has worked for me and have noticed better mileage. mainly on long trips. I don't think you may notice that much difference around town stop and go type but may be an improvement. It will probably get rid of your spark knock and the engine seems smoother when I use higher octane gas. It should keep your engine cleaner too.

I found this about spark knock

SPARK KNOCK

Definition: This is the pinging or rattling noise sometimes heard during acceleration that indicates detonation is occurring inside the engine.
Spark knock can be caused by a variety of things including using low octane fuel, over-advanced ignition timing, too much compression (often due to a buildup of carbon in the combustion chamber), by an inoperative EGR valve, and/or by too much heat. If switching to a higher octane fuel doesn't cure the problem, the cause should be investigated because prolonged or heavy knocking can damage the engine.

 

Yea, I know about Knock, but it's just a little hard to belly b\up to filling up the tank when you have the 35.7 tank like I do! Going to use some octane booster for the full tank I have now, then try out about a half tank of premium next time I fill up

 

Premium gas and octane booster did not fix the problem with my truck.

The computer had to "re-learn" the spark advance and that was done by disconnecting the battery.

But hey, what do I know?