Toyota's official word on Pinging or Knocking

[Zhehan]

There are a lot of posts about pinging or knocking. Sometimes, there's definitely something wrong with your engine when this happens. Other times, for the occasional occurrence, there's nothing wrong with the motor, just the fuel. And, other times, Toyota says it's just "Normal" and nothing to get concerned about.

I experience pinging during Summer months with the AC on. Not all the time, but under specific conditions and only below 2000 RPM, before the Knock Sensors are utilized. They work from 2000-5600 RPM according to the FSM. This pinging happens when I run 87 octane fuel that contains 10% Ethanol, which is the only kind of 87 octane fuel available where I live. I can get non-ethanol premium at a few locations if I'm willing to drive a bit, but non-ethanol regular is hours away from me.

There is nothing wrong my engine. It runs great and is full of get-up-and-go. My fuel trims are normal, my MAF is clean, O2 sensors have been replaced, I've ran injector and fuel system cleaners, checked plugs, wires, the Cat isn't clogged, etc. It's done this since I've owned it and 10% Ethanol fuel became the only, commonly available fuel around here. I have to run TopTier gas as well. It's worse with off-brand fuel. It's always been this way. I've owned this truck since December, 2001. It was a Dealer's shop vehicle and I bought it w/ 34K on it. Manf. Date is 10/99 and it was pristine when I bought it. I know the guys at the shop I bought it from.

I run 89 Octane 10% Ethanol fuel to eliminate the pinging. I get better fuel economy as a result.

The pinging I experience is expected behavior according to Toyota. It's in the Owner's Manual. Here's a link to the manual on Toyota's website: Toyota Manuals and Warranties | Toyota Owners

Here is an excerpt from the 2000 4Runner Owner's Manual concerning the above:

See how it says 87 or Higher? That means that 87 is the MINIMUM you can run, not that you have to and that it's the only fuel that works in your motor. I think the 5VZ-FE has an aggressive Timing Curve and can benefit from higher octane fuel. So, if you're like me and your truck pings occasionally, it's "Normal" according to Toyota. Not everyone will experience this, but it is probably more common than not.

Hope you found this helpful.

 

[pluton]

I got my '97 in 2013 with 120K miles on it. Motor and vehicle all stock except taller springs. It now has 212K miles. On mine, the only way to never get pinging in normal driving is to use 89 octane. That's the "mid grade" gas here. If I should have to buy gas at a station somewhere that only has 87 and 91, I will buy the 91. It's all 10% ethanol around here, BTW.

 

[jgue467]

Crazy - I have not experienced pre-detonation in any situation - low altitude or high (is I-70 west of Denver enough).

Guessing ignition timing has been verified to be between 8-12 btdc?

 

[ArthurKotb]

I used to have an '89 pickup with the 3.0 L engine. Around 130K miles it started to ping quite a bit. I was driving back and forth to work on the Interstate at 70 mph each way, 23 miles one way. For about 6 months before that it was 90 miles one way. I ran 87 octane

I took it to the Toyota service department and they said they could inject something into the cylinders and let it sit overnight. I think it was supposed to dissolve carbon buildup. I let them take it and picked it up the next day and it never pinged again. Eventually I sold it to my brother at 193K miles and he said as long as he had it there was no pinging.

I have no idea what they put in the cylinders; kerosene maybe???

 

[Zhehan]

The thing is, Toyota states very clearly that occasional pinging is nothing to be concerned about. They KNOW it's going to happen to some people. Manufacturing tolerances and all.

I was speaking to Gadget of URD about piggyback computers and the one that they sell. I asked him if they offered a basic tune and he said they could not for the 3rd Gen 4Runners and Tacos with the 5VZ-FE because they are "wildly all over the place". Which goes to my point about manufacturing tolerances and how different most people's experiences can be. I used to have a piggyback that allowed me to alter timing advance and retard, along with fuel trim changes. It died after 20 years and I was looking to replace it. It was nice to be able to dial things in.

I'll take a look at the timing at idle and update the post.

EDIT: I just checked and at idle, with a fully warmed up engine (I just got home from work) @700-ish RPM the Timing is 10* BTDC on my truck.

 

[brillo_76]

I have ran Toyota for over 30 years. I don't recall much pining. I had the Toyota tick and the valves out of adjustment. I always run 87 fuel which is now 10 to 15% ethanol. I cant recall any of my 3rd gens pinging. Its almost as if your fuel isn't even 87 octane. Hence why you need to run the mid grade to get the pining to stop. If higher grade fuels eliminate the pinging. I would be suspecting the fuel itself more then anything else.. Especially if you want over the rig with a fine tooth comb.

 

[ArthurKotb]

On my '89 is was a constant ping, easy to recreate, especially on the Interstate when I would accelerate, and it didn't have to be a hard acceleration. It would ping around corners in city traffic, like when you lug the engine in 3rd or 4th. After the Toyota service center put whatever it was in the cylinders and left it overnight it never did it again. YMMV

 

[Zhehan]

I have ran Toyota for over 30 years. I don't recall much pining. I had the Toyota tick and the valves out of adjustment. I always run 87 fuel which is now 10 to 15% ethanol. I cant recall any of my 3rd gens pinging. Its almost as if your fuel isn't even 87 octane. Hence why you need to run the mid grade to get the pining to stop. If higher grade fuels eliminate the pinging. I would be suspecting the fuel itself more then anything else.. Especially if you want over the rig with a fine tooth comb.

It doesn't matter which brand I run, but some are definitely worse than others. As I mentioned in my original post, it's always done this. It's in the manual that it may ping from time to time. So...

 

[brillo_76]

It doesn't matter which brand I run, but some are definitely worse than others. As I mentioned in my original post, it's always done this. It's in the manual that it may ping from time to time. So...

Crazy. How many miles on the engine and are the valves in spec. If its over 250K they may need adjusted. I do find this interesting as none of my 5vz-fe ever ping. As I run 2 to 3 of these at time.. I just get the injector noise that I just ignore as long as they are all firing well... So that's why this post is interesting to me.