Mangled spark plug

[mechanicboy]

My friend's mom has a 2002 Liberty with the 3.7 and it recently quit on her. She had a mechanic look at it and he thinks it sucked a valve which it might have because the passenger side front spark plug has markings of being physical damage.

My question is if this is common and it might be something else? What are the chances I can get away with just replacing the head?

Any info is appreciated as I do not know anything specific about the 3.7 engine.

 

[HoosierJeeper]

I've never heard of that happening. Welcome to JKJ.

 

[mechanicboy]

Well is the piston breaking up happen on this engine?

 

[tjkj2002]

Well is the piston breaking up happen on this engine?

When a valve seat drops it can.

The most common issue reason for a valve seat to drop in a 3.7 is due to overheating the engine.It happens and can happen to any engine that uses valve seats pressed into the aluminum head.

 

[mechanicboy]

When a valve seat drops it can.

The most common issue reason for a valve seat to drop in a 3.7 is due to overheating the engine.It happens and can happen to any engine that uses valve seats pressed into the aluminum head.

She said it was running great when she parked it and hours later she came back and when she started it it then stalled. She said she tried to start it again and it ran bad so she turned it off and called a tow truck. She says the gauges said everything was fine when she turned it off because she did notice a plastic smell and figured it was the car ahead of her because the gauges said it was fine and it was running well.

Maybe the smell was her and the gauge was wrong.

 

[yellocoyote]

She said it was running great when she parked it and hours later she came back and when she started it it then stalled. She said she tried to start it again and it ran bad so she turned it off and called a tow truck. She says the gauges said everything was fine when she turned it off because she did notice a plastic smell and figured it was the car ahead of her because the gauges said it was fine and it was running well.

Maybe the smell was her and the gauge was wrong.

Exact same thing happened to mine about this time last year. Drove it 16+ miles to work without issue. Met the hubby for lunch, maybe 2 miles from work. No issues. Went to leave the restaurant to go back to work. Started the KJ... the only way it would stay running is if I left my foot on the accelerator. It sounded horrible! Shut it down and towed it home.

Turns out it was the valve seats on mine. Fortunately, we're decent driveway mechanics (hubby, more than me) and tore the top end of the engine down, had the passenger side head rebuilt for just a little over $350, and reassembled it. It's been running great... so far.

 

[mechanicboy]

Exact same thing happened to mine about this time last year. Drove it 16+ miles to work without issue. Met the hubby for lunch, maybe 2 miles from work. No issues. Went to leave the restaurant to go back to work. Started the KJ... the only way it would stay running is if I left my foot on the accelerator. It sounded horrible! Shut it down and towed it home.

Turns out it was the valve seats on mine. Fortunately, we're decent driveway mechanics (hubby, more than me) and tore the top end of the engine down, had the passenger side head rebuilt for just a little over $350, and reassembled it. It's been running great... so far.

That means there is hope! Thanks for sharing!

 

[yellocoyote]

I used to have more of a write-up that I could share... but it seems that some of the older posts may have been purged. So it's gone. If you have any more specific questions, ask away. I'll answer as much as I can. Good luck!

 

[mechanicboy]

I used to have more of a write-up that I could share... but it seems that some of the older posts may have been purged. So it's gone. If you have any more specific questions, ask away. I'll answer as much as I can. Good luck!

Can I keep the cams timed without special tools? Is there anything surprising that I will fkne when I pull the front cover off?