v8 Pinging/Detonation on hard accel... What's the cause?

[stanleybb50]

Alright guys, I’ve searched this forum extensively trying to find out a definitive answer to my “pinging/detonation” I've been experiencing. FYI that I’ve tried making a switch to mid-grade gas for the last two fill-ups, but it didn’t seem to cure or change anything at all.


--- Pinging/detonation on hard acceleration only (and only occurs right at the 1-2 shift and the 2-3 shift). The ping isn’t that bad, but I definitely hear some valves pinging right at these shift points.

--- Pinging/detonation really bad and extremely noticeable after sitting in traffic with the a/c on for extended periods and then “gunning it”. (Every day I sit in the same slow traffic for like 15 minutes out of downtown Pittsburgh, then get to a merge point and just “punch it”). And it’s in a tunnel, so the pinging is amplified, and QUITE noticeable.


As some of you might already know, I bought my ’06 v8 SRV Runner about 4 months ago. It’s only at 37,500 miles now.

But anyway, last month, I got my Cats changed per the Sulfur TSB, and at the same time, I had a 22” Magnaflow muffler installed. I’ve done a couple full battery disconnects/resets since these were installed so the computer could potentially re-learn the different flows/etc. I don’t “think” I had these symptoms before these were installed, but maybe I didn’t run her as hard before to find out. Think this is being caused by the new cats and the Magnaflow?

Regardless of if this was happening before or after the muffler/cat change, these are the symptoms I am now experiencing. I’m going to do a Seafoam through the vac system when I get home tonight. I’ll report back if that helps.

Anyone have similar experiences? Any fixes?? I hate hearing pinging, because I know how much pressure is being put on those valves, the pistons and cylinders in general, so it just makes me cringe and not want to drive my baby the way I want to! I’m looking for the collective brain of this awesome site to come through! :guitar3:

 

[DC runner]

It happens when you gun it. Premium fuel gets rid of it, but in general, if you SLAM down the gas, you will notice it. If you want to run 87, be nice. Your car has smart computer that will help "re****" or modify timing JUST a bit to take gas choice in effect. Gunning it makes it harder.


I run 87 and 89 and never ping. I also take it easy on my v8 and try to get semi decent MPG.

Did this thing seriously edit out "re****"?

WTF. It did it again. R-E-T-A-R-D, as in SLOW DOWN.

I notice you talking about seafoam.. I don't think that is an issue. Tips:

Detonation can be prevented by any or all of the following techniques:
the use of a fuel with high octane rating, which increases the combustion temperature of the fuel and reduces the proclivity to detonate;
enriching the fuel/air ratio, which adds extra fuel to the mixture and increases the cooling effect when the fuel vaporizes in the cylinder;
reducing peak cylinder pressure by increasing the engine revolutions (e.g., shifting to a lower gear, there is also evidence that knock occurs more easily at low rpm than high regardless of other factors);
increasing mixture turbulence or swirl by increasing engine revolutions or by increasing "squish" turbulence from the combustion chamber design;
decreasing the manifold pressure by reducing the throttle opening; or
reducing the load on the engine.


Full throttle is going to cause a ping or knocking.. even at 91 it can happen.

 

[Atlanta_man]

Never a ping with my V8. Nothing but 87.

There's a knock sensor in the engine head, sort of a microphone used to manage the timing. That, or the connector would be the first thing to investigate.

 

[stanleybb50]

Thanks. Yeah... I honestly don't believe that any knocking is "normal" with any type of gas. I've had several different cars that didn't knock over the years, no matter how hard I mashed the right pedal. I'll definitely check out the knock sensor, but just FYI that I'm not getting any codes or anything right now.

But an update on the Seafoam that I said I was going to use.... WOW. I mean WOOOOOW! I put it in right when I got home from work and was letting it bog down slightly, and put in half the can through the intake, and the other half in the gas tank.

Good holy god... There was soooo much smoke when I started it 15 min later! So much, that I was scared to go on the road, so for about 30 seconds, I just sat in the driveway and revved it for about 30 seconds until it at least slowed down... lol - Imagine being a neighbor, listening to the Magnaflow roar and seeing absolute PLUMES of smoke out the tailpipe. One of those WTF moments in suburbia I'm sure. I was seriously scared someone might call the fire dept! Luckily, no codes were thrown in the process though.

Anyway, during my sprited 10-15 minute drive afterwords, I did notice that the pinging is still there on the spirited 1-2 shifts... But I'll wait and see what happens over the coming days and advise back.

Thanks for the input!

 

[FireTruckGuy]

Did you try switching gas stations? Also, pinging can be caused by oil in the combustion chamber.

 

[stanleybb50]

Did you try switching gas stations? Also, pinging can be caused by oil in the combustion chamber.

Well I have been using different gas stations naturally by stopping on trips/etc.

I'm definitely going to try some 93 next time I fill up (probably this week).

As an FYI, I gunned it again this morning, and still got the pinging on the 1-2 shifts. (On my ridiculously horrible commute, I'm never going fast enough to find out on the 2-3 shift).

On another note, I don't know if it was the cold 57 degree morning, or the Seafoam/Hydrocarbon delete I did this weekend, but my 4R was JUICED UP! I mean, it had some serious ba**s! It was so happy to be run hard too, besides the obvious pinging still on the 1-2 shift... The idle also seemed a little lower (like a healthy 550 RPMs) and smooth as silk too.

 

[stanleybb50]

Just an update to this. Someone else had something ''similar'' going on on the 120 site. Sounds like its either normal, more common than I thought.

Either way, I'm not the least bit worried, despite no changes to my above posts. See thread below:

http://www.toyota120.com/forum/showthread.php?t=22404


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[bdg1967]

Not unque to you

My 04 V8 limited pings in an identical manner. Between shifts gears 1/2 and 2/3.
Dealer says the computer doesn't register and they can't hear on test drive. I chock that up to them not seeing as a profitable or fixable trouble shoot.
I run 91 gas. My big concern is when I tow a boat I hope to buy, will this damage my engine if the ping continues while under a greater load.

 

[MikeInNH]

One thing that could be wrong is the knock sensor. This senses when the engine is knocking and then re****s the timing. Modern engines should NOT be knocking.

 

[DC runner]

Yea. Something is up. I have the V8 and I do not ping, nor do I run high test. I run 87 and 89 when I tow, more for the extra MPG you get from the engine not re****ing than anything else.

No pinging. Ever, that I can recall.

 

[ME08Runner]

Maybe check your plugs to see if they are gaped(sp?) properly or if one of them shows signs of misfire or something like that. If it were something like this could upgrade plugs to better metallurgy.

I would have thought that if the knock was really that bad that the sensor would throw a code, so if there's a way, check that too?

If the higher octane stops it, then you might have to stick with that. Could be an issue where the stock ecu is having trouble moderating spark timing during the shift.

 

[MikeInNH]

Pinging is NOT a missfire...and it won't through any codes.

Could be an issue where the stock ecu is having trouble moderating spark timing during the shift.

It shouldn't..but that's a possibility.

I still think there's a problem. If it was an older car I'd say check ignition timing...but that's not possible in most modern vehicles.

 

[Bahnstoermer]

But an update on the Seafoam that I said I was going to use.... WOW. I mean WOOOOOW! I put it in right when I got home from work and was letting it bog down slightly, and put in half the can through the intake, and the other half in the gas tank.

Good holy god... There was soooo much smoke when I started it 15 min later! So much, that I was scared to go on the road, so for about 30 seconds, I just sat in the driveway and revved it for about 30 seconds until it at least slowed down... lol - Imagine being a neighbor, listening to the Magnaflow roar and seeing absolute PLUMES of smoke out the tailpipe. One of those WTF moments in suburbia I'm sure. I was seriously scared someone might call the fire dept!

Followed your link here from 120. Thanks for the unexpected laugh. That was a hilarious depiction of the SeaFoam procedure!

 

[Bahnstoermer]

I had the 120 thread.

I have two tanks of 93 octane through the truck and that seems to have helped, though once realizing what it is I haven't been driving it so damn hard trying to figure out what was going on either.

Also for the boat comment, I tow 4500 lbs of boat and never noticed any issue last year. You'll be fine in that department as far as my experience goes. I think I had a bad tank of gas, then exacerbated the problem trying to figure it out by running it hard, and that with some better fuel and a little time it went back to a level that I confirmed was "normal" compared to another 4Runner V8.

That settled my mind on the whole thing, and I don't think I hear it much anymore. Probably 60% reality change, 40% mentally relaxing over what was left.

I would definitely run a few tanks of 93+ and see what happens for anyone noticing the same thing.

I will post back on the 120 thread in a few more weeks with another update.

 

[20034RunnerV84x2]

Might need a possibly need a valve job if it's coming for the valves, or it could be the VVT-I because I don't hear anything your describing on my 03 V8, witch has no VVT-I.

 

[stanleybb50]

Eh... I was under the runner today to get at the infamous ''fourth bolt'' to pull the headlights out to black them out and noticed my front skid plate is a bit loose and rattles if I smack it.. Who knows, could be this.

I'm not too worried, but I distinctly remember this starting around the time I had my Magnaflow muffler installed. Coincidentally, I also had the sulfur tsb done at the same time... Who knows.

And I gotta get a couple bolts to replace the lost ones on the skids... Heck, I'm gonna actually have to drill out a rear one. One of them is froze solid.


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[TRADICLES]

pinging

my 06 V8 also pings with hard acceleration.

 

[MikeInNH]

Be careful with the knocking...Prolonged knocking and destroy and engine.

 

[DC runner]

How hard are you flooring it? I cannot recall any pinging or knocking in my V8....

 

[stanleybb50]

Still got some knocking when I gass 'er up... I even threw in 89 octane this tank and more of same...

Not that noticeable, but I notice everything with my ride. And it'll do it under even like 3/4 gas if I hit it suddenly.