Spark plug knock or something worse?

[Saharacon]

Long story. 2010 Jeep irregular oil changes. Mostly a offroad toy and snow. Last winter went wheeling. Was drifting around hit rev limiter jeep shut down. Restarted with out any noticeable issues. Went home and drove around on weekends with it for 3 months no problems.

Mpg starts to drop off sharply about a month ago. Figured at 110k miles time for tune up. Found during spark plug changes cylinder 6 spark had a closed gap. Hmmm also my exhaust manifolds on both aides had missing bolt heads one right next to cylider 6.. Replaced manifolds and bolts and gaskets. Plus champion spark plugs and a new blue stream distro. Oil change with royal Purple. Go to start the jeep and a horrible metal on metal knock is heard. Very fast paced.

Shut engine down. Check plugs new plug is crushed on cylinder 6. Okay.. weird. Defective plug? Get new NGK plug for that side install try again. Knock is still there very loudly. Let jeep try to idle for a second eventually it stalls. Pulled plugs again theyre costed in fresh fuel now but nothing crushed.

About to pull valve covers and start taking a deeper dive. Any suggestions? Should I go ahead and swap all my plugs out with NGk? I heard champion was crap.

 

[bobfriesenhahn]

I sounds like it will be necessary to pull the head to investigate, unless there is some tiny camera which can enter via the spark plug hole. Probably foreign matter in the cylinder which hopefully has not destroyed the cylinder/piston/head.

 

[Saharacon]

I sounds like it will be necessary to pull the head to investigate, unless there is some tiny camera which can enter via the spark plug hole. Probably foreign matter in the cylinder which hopefully had not destroyed the cylinder/piston/head.

This is my next step this week. I just find things very odd but thats my luck. I'm hoping if there is an issue it's in the head and I can just have a new head put on and be good. I do most if not allnwork myself but I don't feel confident diving into pistons

 

[Saharacon]

Found these metal shavings behind the throttle body after removal. Tomorrow's job tsckles the manifold and valve covers.

 

[cozdude]

Your piston is smacking the spark plug. You did some big damage to the head/valves and prob the piston when your over rev’d it. Prob other internal damage. Start looking for a new engine…….

 

[Saharacon]

Your piston is smacking the spark plug. You did some big damage to the head/valves and prob the piston when your over rev’d it. Prob other internal damage. Start looking for a new engine…….

Kinda what I'm leaning towards as well. These are big chunks. Oops
Head and valve demo coming up in the few couple days so I'll get a way better look at the damage. If the pistons are in good shape im thinking of trying new heads they're only 250 each side local remained. If pistons show any signs of damage time for new engine thinking I might go with jasper unless rebuilding a single cylinder is a possibility

 

[cozdude]

Kinda what I'm leaning towards as well. These are big chunks. Oops
Head and valve demo coming up in the few couple days so I'll get a way better look at the damage. If the pistons are in good shape im thinking of trying new heads they're only 250 each side local remained. If pistons show any signs of damage time for new engine thinking I might go with jasper unless rebuilding a single cylinder is a possibility

Even if you dont see piston damage it doesn’t mean there isn’t rod, bearing, or crank damage below.

 

[Saharacon]

Even if you dont see piston damage it doesn’t mean there isn’t rod, bearing, or crank damage below.

Any particular way to verify? Pulling pan and inspecting with manual rotation? I have the jeep Bible but books are only good for so much before experience is needed

 

[jeeeep]

if you're finding metal pieces, doing a full tear down is the only way to rule out any other damage.

Then you may as well do a complete rebuild, reman engine may be cheaper.

 

[Saharacon]

if you're finding metal pieces, doing a full tear down is the only way to rule out any other damage.

Then you may as well do a complete rebuild, reman engine may be cheaper.

I'm looking at 505a stroked 3.8 dude its insane all the 5.3 and 6.0 ls engines are gone. My whole ls swap plan is outta the budget now with like engine costs upwards of 8k.

 

[Bierpower]

I'm looking at 505a stroked 3.8 dude its insane all the 5.3 and 6.0 ls engines are gone. My whole ls swap plan is outta the budget now with like engine costs upwards of 8k.

They're still out there for $4k you just need to move up to an LT.

L83 5.3 ENGINE with 8l90e 4WD Transmission Gen V LT Swap LIFTOUT 8 Speed Low Mi | eBay

<p>L83 5.3 Engine with 8l90e 4WD Transmission Gen V LT Swap LIFTOUT 8 Speed low Miles. Condition is "Used". Shipped with Flat Rate Freight for $295. </p><br /><p>Must be picked up at freight terminal or shipped to a commercial address with dock/forklift. </p><br /><p>Note: ECM & Catalytic...

www.ebay.com

They haven't made a production vehicle with an LS for nearly a decade. They're getting sparse.

 

[Saharacon]

They're still out there for $4k you just need to move up to an LT.

L83 5.3 ENGINE with 8l90e 4WD Transmission Gen V LT Swap LIFTOUT 8 Speed Low Mi | eBay

<p>L83 5.3 Engine with 8l90e 4WD Transmission Gen V LT Swap LIFTOUT 8 Speed low Miles. Condition is "Used". Shipped with Flat Rate Freight for $295. </p><br /><p>Must be picked up at freight terminal or shipped to a commercial address with dock/forklift. </p><br /><p>Note: ECM & Catalytic...

www.ebay.com

They haven't made a production vehicle with an LS for nearly a decade. They're getting sparse.

Thanks I havent kept up with much been running a hvac business the past 5 years

 

[JT@623]

Thanks I havent kept up with much been running a hvac business the past 5 years

They're still out there for $4k you just need to move up to an LT.

L83 5.3 ENGINE with 8l90e 4WD Transmission Gen V LT Swap LIFTOUT 8 Speed Low Mi | eBay

<p>L83 5.3 Engine with 8l90e 4WD Transmission Gen V LT Swap LIFTOUT 8 Speed low Miles. Condition is "Used". Shipped with Flat Rate Freight for $295. </p><br /><p>Must be picked up at freight terminal or shipped to a commercial address with dock/forklift. </p><br /><p>Note: ECM & Catalytic...

www.ebay.com

They haven't made a production vehicle with an LS for nearly a decade. They're getting sparse.

The LT is the new LS and the way to go

 

[Bierpower]

Thanks I havent kept up with much been running a hvac business the past 5 years

I just did mine last summer so I'm in the know for the most part.

 

[OverlanderJK]

I just did mine last summer so I'm in the know for the most part.

 

[Bierpower]

View attachment 375153

Pretty much

 

[sm31]

Since this issue may involve the rev limiter: Are 3.8's "more" susceptible to damage than other motors if they bounce off the limiter? Some engines can hit the rev limit regularly without damage but it sounds like this is not one of them?

 

[bobfriesenhahn]

Since this issue may involve the rev limiter: Are 3.8's "more" susceptible to damage than other motors if they bounce off the limiter? Some engines can hit the rev limit regularly without damage but it sounds like this is not one of them?

Only if the engineers were stupid. If it is a manual transmission it is not the engineers who were stupid.

 

[Saharacon]

I'll post pics as I go along. Upper and lower intake manifold out of the way. Fuel Injection out. Zero signs of valve damage on top of head. Will need to now pull heads and inspect bottom plus pistons.

One thing I noticed. Cylinder 6 ports have tiny tiny metal shavings in them. Nothing severe fine dust maybe 1 or 2 larger chunks. Trying to up load a pic.
Also fuel Injector for Cylinder 6 has some build up on it. The other 5 were clean as a whistle.

 

[Saharacon]

Since this issue may involve the rev limiter: Are 3.8's "more" susceptible to damage than other motors if they bounce off the limiter? Some engines can hit the rev limit regularly without damage but it sounds like this is not one of them?

From what I've heard speaking with 3 different jeep guys. One of them being from 505 performance. The 3.8 is horrible with heat. It's like it was designed to manage heat in the worst way possible. Everything just over heats and wears out. It doesn't move enough air for what it's worth. There's a HO 3.8 from 505 and 4.1l conversion that solve most if not all issues the stock 3.8 has in the jeep.