Did a tune up...

[87silveradok20]

Today I finally got around to replacing the plugs, wires, cap, and rotor on my 89 350 tbi. Everything that came off looked ok except one plug. What are your guys thoughts. What caused this and how do I keep it from happening again.

You must be registered for see images attach

You must be registered for see images attach

Sent from my iPhone using Tapatalk

 

[1987 GMC Jimmy]

Did it look like that when you pulled it out with a missing ground and center electrode? I'd check number six to make sure the valves are adjusted properly, they appear to operate correctly with no bent pushrods or off kilter rockers, and that the compression is good. What brand of plug is that? I and most others run Delco plugs and ignition parts, and I'd suggest the same for you. For good measure, I'd verify that the timing isn't too excessive. If it was, it should show up on all the plugs, but your initial setting is something that every homebrew gearhead should know about their vehicle.

 

[PrairieDrifter]

I would get a compression test gauge and test all of your cylinders for compression, that plug looks like it has oil buildup from blow by. Butttt as to why the prong is missing on the spark plug I don't know, did you pull it out like that? It looks like the plug itself is pretty beat up, if that's how the plug looked when it came out, then theres only one place that chunk of metal could have ended up so. I would look inside that cylinder and see if you can see any damage, you might want to look at getting or borrowing a boroscope I think theyre called, its just a small camera with a flexible end. Hopefully inside that cylinder doesn't look like the sparkplug itself.

Did you notice anything strange? Was it running like **** or died or something? Or were you just doing routine maintenance?

x2 on the plugs. Better quality plugs would be the only way to keep that from happening again

 

[1987 GMC Jimmy]

I would get a compression test gauge and test all of your cylinders for compression, that plug looks like it has oil buildup from blow by. Butttt as to why the prong is missing on the spark plug I don't know, did you pull it out like that? It looks like the plug itself is pretty beat up, if that's how the plug looked when it came out, then theres only one place that chunk of metal could have ended up so. I would look inside that cylinder and see if you can see any damage, you might want to look at getting or borrowing a boroscope I think theyre called, its just a small camera with a flexible end. Hopefully inside that cylinder doesn't look like the sparkplug itself.

Did you notice anything strange? Was it running like **** or died or something? Or were you just doing routine maintenance?

x2 on the plugs. Better quality plugs would be the only way to keep that from happening again

Borescope is a good idea, and I agree about looking for whatever this plug ejected into the motor. Amazon sells them for a few bucks that you can plug them into the computer.

 

[74 Shortbed]

I got one off E-Gay for $12 that plugs into my phone, has 15ft coil has a light, takes pics and videos, clear as can be...

 

[Honky Kong jr]

I got one off E-Gay for $12 that plugs into my phone, has 15ft coil has a light, takes pics and videos, clear as can be...

Link????

 

[74 Shortbed]

Link????

Here ya go, all kinds of em..

https://www.ebay.com/sch/i.html?_od...roid.TRS0&_nkw=endoscope+android&_sacat=31460

 

[Frankenchevy]

Do the valves for sure. One picture it looks lean the other looks tight in the exhaust. X2 on the bore scope. Although that electrode was probably chewed up and spit out already. Hopefully it didn’t chew the cylinder up.

Does it burn oil?

 

[Frankenchevy]

You can melt a plug in a lean condition. It’s hard to tell in the picture. If it’s light brown and melted...

 

[87silveradok20]

Did it look like that when you pulled it out with a missing ground and center electrode? I'd check number six to make sure the valves are adjusted properly, they appear to operate correctly with no bent pushrods or off kilter rockers, and that the compression is good. What brand of plug is that? I and most others run Delco plugs and ignition parts, and I'd suggest the same for you. For good measure, I'd verify that the timing isn't too excessive. If it was, it should show up on all the plugs, but your initial setting is something that every homebrew gearhead should know about their vehicle.

That’s what it looked like when it came out. I replaced them with ac Delhi plugs. I’m planning to check timing and compression soon.


Sent from my iPhone using Tapatalk

 

[87silveradok20]

I would get a compression test gauge and test all of your cylinders for compression, that plug looks like it has oil buildup from blow by. Butttt as to why the prong is missing on the spark plug I don't know, did you pull it out like that? It looks like the plug itself is pretty beat up, if that's how the plug looked when it came out, then theres only one place that chunk of metal could have ended up so. I would look inside that cylinder and see if you can see any damage, you might want to look at getting or borrowing a boroscope I think theyre called, its just a small camera with a flexible end. Hopefully inside that cylinder doesn't look like the sparkplug itself.

Did you notice anything strange? Was it running like **** or died or something? Or were you just doing routine maintenance?

x2 on the plugs. Better quality plugs would be the only way to keep that from happening again

That’s how the plug came out. I will have to look into a borescope to see what’s going on in there. The motor was stumbling and had no power and that’s why I decided to replace them all. I replaced these with ac delcos.


Sent from my iPhone using Tapatalk

 

[Charlie]

Here ya go, all kinds of em..

https://www.ebay.com/sch/i.html?_od...roid.TRS0&_nkw=endoscope+android&_sacat=31460

Which one is the one you got?

 

[Frankenchevy]

Now that I can zoom in it looks more black and sooty which I’d guess tight exhaust valve or blow by. They’ll run surprisingly well on 7 cylinders!

 

[Dougnsalem]

Same everyone else said.... Leakdown check, borescope...

When checking the rockers/pushrods, try wiggling the top of the #6 springs- looking for a hammered valve guide. It sure looks like oil consumtion in that cylinder, to me. A ton of carbon there compared to the others.... That could lead to a hot spot, then detonation, blowing off that electrode. (Remote possiblity....)

Does it smoke out the exhaust at all? Pull the pcv- smoke out of the valve cover? Out the dipstick tube? Does the motor have any new/different sounds or noises?

 

[74 Shortbed]

Which one is the one you got?

This one..

You must be registered for see images attach