1998 Toyota 4Runner Engine Knock / Ping

1998 TOYOTA 4RUNNER
274,000 MILES • 6 CYL • 2WD • AUTOMATIC
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4RUNNERRUSSELL
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  • 2 POSTS
Just ran a tank of high octane gas through my 4Runner, + 16oz of that fuel system cleaner stuff you can buy with your gas puchase at the pump.

Now I am back on the normal low octane fuel I use and since filling up with it the engine is making a loud knocking/pinging sound. Can start hearing it around 20-30mph and real loud at idle, 700rpm. At least real loud to me, and by the looks on the faces of those around me, loud to them too.

This has happened once before, about 1.5-2yrs ago, but the noise went away. Will I have to start purchasing high octane fuel now? Any suggestions?

Thanks,
Frustrated 4Runner in Austin
May 21, 2010 at 11:44 AM
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RASMATAZ
  • ✓ASE Certified Mechanic
  • 75,992 POSTS
  • ASE Certified Mechanic
Try cleaning out the EGR valve and see what happens. An EGR valve that's not opening will cause the engine to ping/detonate due to increase engine temperature.
May 21, 2010 at 6:59 PM
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