Destroyed Spark Plug V6 3.4

[2TH4IST]

Op - those look like 2 different manufacturers plugs. Notice one has a sharper taper of the porcelain then the other. The metal usually will melt before the porcelain will. I'd venture to guess it was a plug manufacturing issue. But still check for the other issues other posters have mentioned.

As for the smashed plugs. Yeah, not good. Heads and block could have been over machined. Or issues with bearing/wrist pins. I'd also guess that engine is toasted.

 

[thegipper]

Doesn't look like the plug is hitting or being hit, it looks like melting from lean condition, [MENTION=71960]JohnMc[/MENTION] answered the issue on the 1st page IMO, i'd check the rubber intake boot that hooks to the TB for tears that are creating a massive air to fuel issue because it's after the MAF. If addressed in a timely manner the engine should be fine.

I agree, they don't look like they are hitting anything but are being melted.

 

[phattyduck]

I agree, they don't look like they are hitting anything but are being melted.

Really poor quality knock-off plugs, maybe?

-Charlie

 

[JohnMc]

Get a bore scope and see what sort of evil is in that cylinder... And you likely have a pretty majorly damaged engine.

-Charlie

/\ /\ /\ This. That plug looks like something other than the piston was hitting it. Like perhaps something smaller bouncing around in the cylinder. If it mangled the plugs like that it probably made the rest of the chamber look pretty mangled.

 

[brillo_76]

I am curious if the plugs are OEM, Denso or Amazon , Ebay specials with a good price as that would explain the melting plugs as they maybe counterfeit. Would keep happening if buying the same counterfeit plug. May not be the case, but a possibly.

 

[28petey]

Thanks for reaching out

 

[28petey]

I put Denso in originally. I got more than densos from O’Reilly installed the new set of plugs and it melted two in the number six cylinder so that makes three total.

 

[28petey]

I couldn’t get my hands on a bar scope, but I had a camera with a light on the end and looked on top of the cylinders and didn’t see anything that jumped out. No damage.

 

[28petey]

Good compression good

You have any compression in that cylinder that is doing that to the plugs?

Compression is good for the mileage I guess I just did it today and it’s 160. I need to go get more plugs to install a new plug. I’m thinking that whatever was in there may have blown out? I think you’re right it had to be Inanimate Object

 

[brillo_76]

Compression is good for the mileage I guess I just did it today and it’s 160. I need to go get more plugs to install a new plug. I’m thinking that whatever was in there may have blown out? I think you’re right it had to be Inanimate Object

Ok.. be real Densos then. Interesting indeeed.

 

[28petey]

Ok.. be real Densos then. Interesting indeeed.

OK, so I replaced with verified Denso. No longer getting damage to the plug. After the compression test, which I believe discharged an object. No further damage to the plug thus far. ran diagnostics only to find multiple misfires on the left bank 246. I’m thinking maybe the mass airflow might be not calibrating correctly. I’m replacing the mass airflow next and I will post after that.

 

[phattyduck]

OK, so I replaced with verified Denso. No longer getting damage to the plug. After the compression test, which I believe discharged an object. No further damage to the plug thus far. ran diagnostics only to find multiple misfires on the left bank 246. I’m thinking maybe the mass airflow might be not calibrating correctly. I’m replacing the mass airflow next and I will post after that.

Please don't throw out a likely good OEM MAF sensor... just clean it.

What wires are on there? 2/4/6 are all fed via the wires, while 1/3/5 are direct off the coils. Knock-off plug wires could cause issues that you are describing.

-Charlie

 

[28petey]

Please don't throw out a likely good OEM MAF sensor... just clean it.

What wires are on there? 2/4/6 are all fed via the wires, while 1/3/5 are direct off the coils. Knock-off plug wires could cause issues that you are describing.

-Charlie

Thanks Charlie. I didn’t see this before replacing the near OEMMAF same issues. I will take it back off and get some MAF cleaner …attaching picture of what I thought were OEM wires.

 

[phattyduck]

Thanks Charlie. I didn’t see this before replacing the near OEMMAF same issues. I will take it back off and get some MAF cleaner …attaching picture of what I thought were OEM wires.

OEM wires were likely Yazaki, not NGK or Denso. (fun fact, most 3rd gen 4Runners came from the factory with 3 NGK and 3 Denso plugs) Also, trust NOTHING on Amazon or eBay if it is branded Denso or NGK. Way to many fakes to know you got the right parts.

Genuine NGK or Denso wires will likely work. Source from a local auto parts store, RockAuto, etc.

-Charlie

 

[brillo_76]

OK, so I replaced with verified Denso. No longer getting damage to the plug. After the compression test, which I believe discharged an object. No further damage to the plug thus far. ran diagnostics only to find multiple misfires on the left bank 246. I’m thinking maybe the mass airflow might be not calibrating correctly. I’m replacing the mass airflow next and I will post after that.

That's good news on the plug. I really doubt your MAF would be causing misfires on only on left bank. That doen't make sense at all.

I suspect you got counterfeit plugs especially if every now is fine with the plug. Charlie advise is solid. Start over with known good plugs densos or NGK. With known good geniue wires too.. AS if you had one junk plug and it kept occuring its really looking like you had junk parts...:-(

Which explains everything you are seeing. I agree 100% with Charlie's assessment on this one.

 

[28petey]

Back to the board

OK, thanks guys, time to get some legit parts. I guess I had no idea that there are so many imitations out there. I will be filling you in as things transpire

 

[Pyral]

Don't buy parts off amazon unless you have confidence you can detect them, I've received fakes. You can't even trust the reviews, Amazon mixes vendor parts together, so people can receive fake parts and real parts.

Rockauto is where you want to go for aftermarket parts, their prices are usually comperable to Amazon and you wont get fakes. Or any other reputable online shop is fine like Summit.

The Denso wires you got are good, it's what I use, but yours might be fake.

DONT throw out the original MAF, clean it. DONT use an aftermarket MAF if you need to get a replacement, Toyotas don't tolerate aftermarket sensors.

 

[brillo_76]

OK, thanks guys, time to get some legit parts. I guess I had no idea that there are so many imitations out there. I will be filling you in as things transpire

Yes. Its truly sad how bad its become. Amazon and Ebay do nothing about it either. All parts have to come from legit sources. Auto parts stores, rock auto or dealers. If you don't you can see what happens. Also most aftermarket parts are junk too sadly. Its how these rigs were so reliable. They had good qaulity OEM parts in them. Even some of the OEM mfg parts aren't the same quality as the OEM spec.

Look at the issues and time you lost. All because your part sources were junk. Its basically a learning experience.

We almost need a sticky on the forum here that says if you didn't use genuine parts. Go back and put the original part in.

Because we seen it all from sensors, belts, spark plug and wires. Head gaskests, Seals.. etc. That's one of the first questions we asked when something is replaced and doesn't work properly. :-(

 

[28petey]

Thanks again for all help. I ended up accepting that there is some sort of internal damage n if I don’t stop pushing it I will have total engine failure

in the process of replacing with used motor this weekend… removed the oil pan saw a little bit of milky very little. Forgot to take a picture of that.Can’t wait to tear the old engine apart and see what happened?

 

[brillo_76]

Been there done that. These engine swaps are not horrible, but do take some time to do.