[Yaboithatdude]

Story goes: I was driving on the highway and did a little pull up to 70mph. The car hesitated a little which made me chill out snd drive like a grandma. Around 5 minutes later the car started dying bad and had smoke coming from the rear (unsure of color because friend saw it following behind) and had to pull off the highway and have the car towed home. Couple weeks later i get around to pulling the intake off and see oil dumped into the intake, one of the cylinder 1 intake valves smashed in, along with the cylinder one sparkplug being completely smashed in. Cylinders 1,2,3 sparkplugs had oil on the top (I believe from a faulty valve cover gasket) and none had major damage like cylinder 1. Anyone have any ideas because im at a loss right now. I know im going to have to fully tear down the motor but I would like to have a idea of what happened and what caused this if anyone has had experience with this before.Thank you for reading.

 

[Falkon45]

Looking at the pictures posted, it look like that valve failed. That's all I can assume, since it doesn't seem like any other valves are damaged. Until you tear the engine apart, that's the best answer I can give you.

 

[Yaboithatdude]

Looking at the pictures posted, it look like that valve failed. That's all I can assume, since it doesn't seem like any other valves are damaged. Until you tear the engine apart, that's the best answer I can give you.

From what I can see, all the other valves dont have noticable damage, and only cylinder one has this kind of substansial damage. But any help is welcome, and if you dont mind, what do you mean that valve failed? Thanks for the help

 

[Thatblueis]

My guess would be weak springs let the valve hang down too long and touched the piston. You can pull the springs out and have them checked.

 

[Falkon45]

From what I can see, all the other valves dont have noticable damage, and only cylinder one has this kind of substansial damage. But any help is welcome, and if you dont mind, what do you mean that valve failed? Thanks for the help

From what I'm guessing, the valve gave up the ghost, and broke at the stem on the upstroke. But, Thatblueis does have a more believable answer.

 

[Hodgdon Extreme]

Either you dropped a valve, or you had piston-to-valve contact on account of an over-Rev, moneyshift, cambelt or camdrive failure, etc

How many miles on the engine?

Prolly not worth rebuilding; just buy a good used engine.

 

[ill_mannered]

Vtec kicked in too hard.

 

[Yaboithatdude]

Either you dropped a valve, or you had piston-to-valve contact on account of an over-Rev, moneyshift, cambelt or camdrive failure, etc

How many miles on the engine?

Prolly not worth rebuilding; just buy a good used engine.

Its just got over 122k, its the only reason I want to rebuild because its still relatively low mileage for the jz. Ill probably have to swap in another motor from what I can see currently. Will send more photos the more I pull off parts, thanks 4 the help 🤙

Vtec kicked in too hard.

The VVtec was insane 😞😂

Alright,

My guess would be weak springs let the valve hang down too long and touched the piston. You can pull the springs out and have them checked.

Didnt think about that, would make sense considering only one of the two valves hit and broke right? Ill check the springs once I get the exhaust off. Thanks for the help 🤙

 

[Theneil300]

Lose a bolt into it? Throttle blades can crack and shed bolts sometimes

 

[Thatblueis]

Its just got over 122k, its the only reason I want to rebuild because its still relatively low mileage for the jz. Ill probably have to swap in another motor from what I can see currently. Will send more photos the more I pull off parts, thanks 4 the help 🤙


The VVtec was insane 😞😂

Alright,

Didnt think about that, would make sense considering only one of the two valves hit and broke right? Ill check the springs once I get the exhaust off. Thanks for the help 🤙

Should be good just rebuilding the head unless the piston is damaged.