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2001 Nissan Xterra 2.4L L4 2wd
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Discussion Starter · #1 ·
Hello, had no compression in my cyl 4 chamber took off the head and found this.. the valve itself doesn't look damaged, but you can easly see that the valve is not fully sitting in properly.. I've never done any type of valve repair but does it look salvageable? Or is it bent and needing replacement?
Thanks!

 

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2000 Xterra XE 4x4 3.3L AT
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Can’t tell from those pictures. I assume the cams are still in place? If so roll the cams and see if the valves seat.

Also I assume that is number 4? Can you post a picture of the top of number 4 piston? Also a picture of number 4 cylinder wall.
 

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2001 Nissan Xterra 2.4L L4 2wd
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83 Posts
Discussion Starter · #3 ·
Can’t tell from those pictures. I assume the cams are still in place? If so roll the cams and see if the valves seat.

Also I assume that is number 4? Can you post a picture of the top of number 4 piston? Also a picture of number 4 cylinder wall.
Sorry the pictures are bad, I can get better ones in the morning... but to give a visual description there is a nick mark on all 4 pistons from the intake valves.. and the cylinder walls all look good though..


 

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Also...
Inspect the lobes on the camshaft. Worn or damaged lobes can prevent the valves from actuating properly.
Inspect the valve springs. Broken or worn springs can likewise prevent the valves from closing properly.

I assume the head gasket looked okay?

Not seeing any obvious damage to the top of the piston.
You may have to remove the valves to fully inspect them. It's not always the top of the valve that bends, but rather the shaft. This can result in the valve binding in the guide and not closing all the way. As mentioned, rotating the camshaft to see what the valves are doing may help determine this, but removing them completely will give the most definitive answer. They should just slide right out after the springs are removed. If they bind or feel stuck then they're likely bent.
 

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04 4x4 v6
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And just to check some more things.
Check for play in the valve guides.
And to know if the valves are seated you can spray pb or something safe behind the valves, and if it makes it though = leak, or sometimes you can use light behind it to inspect for ill-seated valves.
Just some more options.
 

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2015 Xterra Pro-4X
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Sorry the pictures are bad, I can get better ones in the morning... but to give a visual description there is a nick mark on all 4 pistons from the intake valves.. and the cylinder walls all look good though..


I can see the "impressions" your valves have made in the outer edge of the piston top. The valves have struck with some serious force and are likely bent and require replacement. Great time for all new valve guides and a sporty 3 angle valve job cut on all valve seats in all cylinders.
 

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2000 Xterra XE 4x4 3.3L AT
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The above is what I see as well.

Want to know how tired I was when I posted the above questions? I looked straight at the pic and in my head I saw a VG33E cylinder head. 🤪🤯😖 I have not had a KA24 torn down but I’m going to assume it’s a flat top piston, no valve pockets, and those are impact marks from a valve strike. You are going to have multiple bent valves not just number 4 cylinder.

If I had to guess at the cause I’d say massive over rev to many downshifts way to fast.
 
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