QuestionOk, I'll try the 91+ octane continuously and see what happens. I forgot to mention that my truck is the 8 cylinder, I assume it still applies, correct?
Thanks.
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The text above is a follow-up to ...
-----Question-----
Hi, my 2006 4WD 4Runner Sport has only 7500 miles and it has started pinging just recently. I brought it to the dealer today and they said it's "normal" and they could not do anything about it! Excuse me, I just spent $40k+ on this truck and am not about to listen to that for the next few years. It pings upon acceleration and particularly as it shifts gears. It's worse when I tow, which is at least once a week. I only use Citgo or Shell gas and occasionally a different big name brand like Mobil, etc. I run 87 octane (per the manual) and tried super unleaded after the pinging started, to no avail.
Second problem is strange. At precisely 60-63mph, there is a "howling" noise coming from somewhere (hard to pinpoint). It does not occur until I hit that exact speed and will stop higher than that speed. As I decelerate it will start again between 60-63 and you can still faintly hear it below those speeds while decelerating. The dealer is trying to blame it on the roof rack which they say is non-factory. It came with the rack which I am pretty sure IS factory since I did not purchase a custom one. Regardless, the howling sound was not there for most of the current 7500 miles so why would it start now if it was the roof rack???
PLEASE HELP!!
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Ugh, it's pinging becuase you're using the incorrect grade of gas.
It wants 91. See, here's the actual engine intro & specifications published in the engine manual.
http://img.photobucket.com/albums/v414/Toysrme/Data/1gr.jpg
87 octane will let it ping some. The knock sensors will hear the pinging, dial out timing over time until it stops, wait afew firing cycles & then it'll re-advance it abit every firing cycle.
Short of higher octane. You can try creating a cooler combustion chamber on your own, but I can't tell you it'll work.
You can try dropping ONE heat range colder NGK, or Denso spark plugs... (Those plugs are not like others. They run 100*C temp ranges, anything else runs 70*F. large differance there.)
Install a very, very small amout of water injection. Water injection... Greatest thing ever you've never heard of. Doesn't take much, your engine is normally aspirated.
It'll run 87 octane. Par the current revised SAE horsepower rating rules, it WANTS 91 octane to achive peak power.
For the howling. IDK man, you can try taping sections yyou think it may come from up to see if it changes any until you can hit it. Or get a passanger with something like a $2-3 mechanics stethescope maybe.
IDK maybe the rack shifted. Is it a window leaking air & whistling?
I dont' do sales, don't know anything about roof racks. I always hated them with a passion. Doesn't really increase the cross sectino of a vehicle, but they increase the coeffecient of drag to about semi-truck levels on most cars.
For example. :)
@ 75mph. Your runner looses 42 horsepower due to aerodynamic drag.
@75mph with a typical roof rack's Coeffecient of drag increase added to your car's CD. You loose 63 horsepower.
Crazy for such a little thing aint it?
(Cd*frontal area*(mph^3))
/150,000
Really I wish I could help, but I can't. It's sorta a "yall will have to find the whistle" kind of deal.
AnswerAhhhhh. 2uz-fe. Very strong engine.
http://img.photobucket.com/albums/v414/Toysrme/Data/052uz.jpg
Doesn't apply to the same extint, but it does to some. 10.0:1 compression ratio is nice for 87 octane.
Grab a can of Seafoam & run that through the intake per their directions. And if that doesn't work running some 91octane, or better. Change out your plugs to Denso, or NGK plugs 1 heat range colder than what it calls for.
