Pic of #1 cyl score, salvageable???

[fastinjun]

I took this pic today. The scoring does not look that bad, it extends about 2 inches down. Any opinions? Should this honed/machined? The other cyls look fine.

[tempfixit]

Originally Posted by fastinjun

I took this pic today. The scoring does not look that bad, it extends about 2 inches down. Any opinions? Should this honed/machined? The other cyls look fine.

Pic please, what year?

[fastinjun]

Originally Posted by tempfixit

Pic please, what year?

Oh Sorry, its a 2003 with 84,000 miles

[tempfixit]

Originally Posted by fastinjun

Oh Sorry, its a 2003 with 84,000 miles

Do you have picture to post???

[fastinjun]

Originally Posted by tempfixit

Do you have picture to post???

Sorry about that, completely forgot the pic....

[fastinjun]

Originally Posted by fastinjun

Sorry about that, completely forgot the pic....

When I did the leak down test this cyl lost quite a bit of pressure but when I did the compression test the compression was good. This cyl was not the cause of running bad though Im pretty sure. Number 5 cyl the rocker arms had pulled out of its threads so the valves were not even working.

[fastinjun]

Originally Posted by fastinjun

When I did the leak down test this cyl lost quite a bit of pressure but when I did the compression test the compression was good. This cyl was not the cause of running bad though Im pretty sure. Number 5 cyl the rocker arms had pulled out of its threads so the valves were not even working.

The Cross Hatching is still very obvious in all cyls, shame GM chose to put such crappy parts in their cars, gaskets etc...

[tempfixit]

I assume the coolant in the clyinder is from reemoval of head, correct??

Is there any movement of the piston in the clyinder, meaning sideways, etc???

Have you removed both heads???

What was the condition of the head gasket?

Was the engine burning oil????

How much of a ridge is on the top of clyinder?? Can you catch the ridge with a finger nail???

[fastinjun]

Originally Posted by tempfixit

I assume the coolant in the clyinder is from reemoval of head, correct??

Is there any movement of the piston in the clyinder, meaning sideways, etc???

Have you removed both heads???

What was the condition of the head gasket?

Was the engine burning oil????

How much of a ridge is on the top of clyinder?? Can you catch the ridge with a finger nail???

Coolant is present because I pulled the head. Head gasket looks ok.
This car is my uncles and according to him it overheated, to what extent I dont know. I verified that #2 cyl on the front bank blew the gasket by applying air pressure to the cyl and pulling the radiator cap off and having coolant come out. According to my uncle it didnt burn oil but Im not sure if this scoring was there before the motor over heated or was caused by the over heat.
The piston moves but no more than the other pistons. When I got the van it was missing on one cyl which Ive determined was #5 because the rocker arms puled out of the head, someone apprently tried to helicoil the threads but failed.
Thanks for your input with by the way.

[tempfixit]

What was the compression on the clyinder shown??? How much of a ridge is there on the clyinder wall??? If there was no ridge I would just hone tha clyinder, putting the piston down to the bottom of stroke and making sure to clean the clyinder very well when done. If there is a ridge you would need to remove ridge first or you will probably break the hone when hitting the ridge. I am not sure if you can get a good crosshatch with the piston in the block being the stroke would be shallow. Since you say all clyinders still show crosshatch it may not be worth the effort, but then it may at least remove the glaze on the clyinder wall.

Was there any coolant in the oil????

Are you replacing both heads or just bank 1 head, either way have both heads tested for cracks and warpage so you dont have problems after reassembly.

[fastinjun]

Compression was around 135lbs. Mind you I did the leak down test when it was cold. I think I may do what you suggest and hope for the best. There is no ridge on the top of the cyl wall at all. I will bring the piston down, hone it, clean it out and button it back up. Im replacing both head gaskets, #2 cyl blew but from what I read here on the internet blowing head gaskets is common with these models. I took the heads today to a place nearby to have them tested, I will post any findings.
Thanks again for your help and advice.

[tempfixit]

I do not know if it is recommended to replace head bolts or not on these engines. I would clean the head bolts and check them for being stretched if not replacing with new.

After cleaning threads take a striaght edge and place over threads, if bolt is stretched you will see the threads uneven.

[fastinjun]

Spoke with the machine shop and they suggested replacing the head bolts with new ones. Ive cleaned out all the cyls and they look good aside from the one with the little scoring. I will post what the machine shop says tomorrow if they find anything wrong with the heads. Thanks again for your advice.