Chasing the 2200 rpm ping (2.7)

May be different for 2.7L but for the 3.4L you have to use Duals.

 

I've read about guys on here "gapping" dual ground plugs.. IMO that is unnecessary. The only ones that need to be gapped are the single electrode plugs (And frankly if they're good quality plugs they should be ready to go right out of the box). If you buy good quality dual ground plugs they gap will be much closer than what is shown in the pic, they gap should not be adjusted, and the center electrode should be a perfect circle. The center getting the oval shape is what they look like when they are worn/been in service a long time.. IMO..

Edit.. this is an example of a new dual plug

 

I broke down and took the truck to the dealer this morning. I chatted with the parts guy while I was waiting. I asked him to see what plugs my truck was supposed to have and sure enough, I have the correct plugs(K16R-U). After a bit, the tech came and wanted me to go for a drive with him so we went for a drive. We went to the truck and I explained that I had put 93 octane in yesterday and I wasn't surprised if he didn't hear any pinging. He said that everything looked good(his laptop was hooked up inside the truck) and that the clatter that can be heard at idle is normal. We went for a ride and I was able to get the truck to ping a little bit. He said that since the higher octane gas helped the pinging and everything checks out then the pinging is caused by carbon build up. He monitored the truck while I drove it. I told him about cleaning the MAF, replacing the exhaust manifold and resetting valve lash. He said that if it was his truck he would run the 93 octane out and put in a can of Seafoam at fill up, then run that out and run some 93 through it and then run another can of Seafoam through it. Best part is that they didn't charge me a dime.

Gotcha. Thanks

 

Not going to get into a gapping debate the FSM says .043, but my plugs are Denso from the dealer and electrode tip looks just fine. Not sure why you think it looks eroded, I think the red dust on it is playing tricks on your eyes.

 

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Just my 2 cents bruh..

 

Just thought I would update that I still have spark knock. I haven't pursued this in a few months and nothing has changed. Here's a reminder of what I've done:
1. Denso K16R-U plugs look good with .040 gap (40k miles on them)
2. plug wires have 40k on them and look great
3. EGR valve replaced 40k ago
4. new fuel filter
5. Tried 89 Octane Chevron
6. Cleaned the MAF
7. Replaced exhaust manifold with NWOR header
8. Corrected slightly out of spec valve lash
9. Seafoam through intake
10. took to dealer and all checked out. Tech monitored truck while I drove it(did have 93 octane in it).
11. ran a few tanks of Seafoam through it.

I still haven't done a compression test. Would a hotter or colder plug help with this? Spark knock only occurs once truck is warmed up and between 2000-2500 rpm when under load. So maybe a cooler plug?

 

Have you taken off your intake manifold and cleaned it out real well? There may be a lot of carbon build up in there as well as in the Intake side of the head. There are a few decent YouTube vids out there on how to scrub out your manifold. I think there's even a write up on it her on the forum.

Also, you cAn look into either replacing your or cleaning and glow testing your fuel injectors. If one or more of your injectors has build up on it, you may not be getting full fuel flow causing a leaning condition which can result in pinging.

 

https://www.tacomaworld.com/threads/2-7l-auto-throttle-body-and-intake-manifold-cleaning.328682/

 

Sounds like you still haven't checked/replaced your EGR vacuum modulator. Have you checked/cleaned the EGR passages yet?

 

I really appreciate the responses guys.

I haven't removed the intake and cleaned it. BIG thanks for posting the link. I'll put that on my to do list. It would be a good time to clean the throttle body too.

I haven't checked the EGR or vacuum modulator but the Toyota tech said that it's working properly according to his live data. I recall specifically asking him about the EGR.

 

I took advantage of Partznet.com free shipping and purchased both intake gaskets. My to do list is below. I have a few things in front of these "to do's" but I will get to it. I appreciate everyone's input on this. I'm hoping that some of these procedures will solve the problem. I'm really hoping that I don't have to pull the head and clean off all the carbon to resolve the pinging. I have added some Lucas fuel injector cleaner/conditioner today in the meantime to see if it helps.

- insure egr passages are clear
- pull intake manifold/TB and clean (intake gaskets ordered)
- clean and flow test fuel injectors (I've been researching vids on this)

 

My exact same experience with a 3VZ-FE engine. Turned out to be a clogged VSV valve.

 

I appreciate you sharing. Was your throwing any codes? I just watched a vid where a guy showed how to troubleshoot that. I'll check into that too. Here's the vid: https://www.google.com/url?sa=t&rct...=WOSFmKY15SU&usg=AOvVaw2H8J9Rl27BCtaXUrNfWQt3

 

This engine only had a OBD 1 system that did not give any codes for the EGR. The reason I fixed the EGR system was because the NO (PPM) during Cali smog check was nearly failing. After fixing the EGR the ping went away.

 

Thanks for the explanation. I've always assumed that because I don't have any CEL's and the Toyota tech said the system was working properly that I couldn't be emissions related. But now I'm thinking that maybe a passageway partially clogged or something. I plan to purchase a handheld vacuum pump tester to help me manually test the system. I'm looking at this one.

ILOVA Handheld Vacuum Pump Set Tester for Automotive with Adapters Brake Bleeder Test Kit

https://www.amazon.com/gp/product/B073R8XGX1/ref=ox_sc_act_title_1?smid=A3G2PB6EXY713C&psc=1

 

On my 2.7 my pinging problem was completely worn out iridium spark plugs that were in it when I bought it. I would only get pinging under heavy load like driving up long hills. New cheapo sparkplugs cleared that right up for me and I run 85 octane. But sounds like you've already ruled that out.

P.s. There's no performance difference between a dual ground and single ground plug, no matter what the 3.4 guys read under there hood.

If you've only been putting seafoam in the tank there's a few more things you can try before pulling the intake and head to clean the carbon off. Like seafoaming directly into the intake. I doo this every few yrs just for maintenance. Find a vacuum hose on the manifold that is pretty centered and looks like it'll feed all the cylinders and while it's running slowly pour in or let the vacuum line suck up the seafoam being careful not to kill the engine. If you kill it, no biggy, just start it again. I like to go about half the can then when I feel I'm about there I'll pour enough in to kill it intentionally. Then let it sit for a half our or so then start it up and go for a drive to burn it out. Don't be alarmed by the smoke.

Another option I've never tried but heard good things about is what's called BG systems cleaner. This is done buy a dealer that carries the product, look on there sight to find one in your area. But it's essentially doing the same thing as seafoaming like I mentioned above but more consistent. They hang a little set up under the hood with their cleaner in it and start the car and as it idles it slowly feeds the cleaner in.

 

I appreciate the response. I agree that the single ground plugs are all that's needed. I posted pics of my plugs on page 1 or 2 and folks thought they looked good.

I don't even have to be driving up a hill to get pinging. Just a bit of extra gas like when accelerating without down shifting. The hotter it is outside the worse it seems to ping. Makes me think its related to air intake.

I seafoamed through the intake at 292000 and also treated the tank 2-3 times since then using Seafoam and once using Techron. I repeatedly got a CEL 0420 at ~293200 until I replaced the downstream O2(replaced with Denso). No CEL's since then. I also normally fill up at Chevron but have also trying using other gas like BP.

I'll likely try the BG systems cleaner before pulling the head but plan to verify the EGR passages first. I see a dealer near me, but its a GMC/Pontiac dealer.

 

If I may suggest, if you don't already have a factory service manual they are indispensable. Mine had a complete troubleshooting procedure for the EGR system. IMHO better to troubleshoot correctly than throwing money and time at a problem.
I usually find my FSMs used on eBay.

 

I think I will do that. I only have a Haynes manual. I suspect that any year from 98-04 would work wouldn't you think?