MY Camshaft might be messed up! 09 5.3 Suburban NEED HELP?

[OR VietVet]

Yup CAN of worms LOL. As far as the compression test. What pressures should I be seeing inside the cylinders? I'm assuming if the it does NOT hold AIR then theres my Issue.
Chris

I would think you should see pressures of 170-190 psi with no more than 5%-7% difference between cylinders. Some allow more difference but I like nice even readings. Plenty of videos to show you how.

 

[91RS]

Replace the push rods and you should be fine. Worst case you damaged the lifters. The camshaft should be fine.

 

[drakon543]

Replace the push rods and you should be fine. Worst case you damaged the lifters. The camshaft should be fine.

op stated pushrods were already replaced however i didnt think about lifter damage. if the lifter isnt working a full lift cylinders in question wont get the airflow they need and possibly cause your missfires.

 

[donjetman]

sounds like bent valves to me

 

[iamdub]

The cam isn't gonna get wiped with mere seconds of running. Considering your valve train was shortened by about 1/8"-3/16" (whatever the thickness of the rails is), the springs would've reached coil bind, essentially making them solid, which means the rockers, pushrods and lifters would've taken the brunt of it.

Best case, the springs bound before the valves were opened enough to punch the pistons and your lifters gave away. Worst case, you now have bent valves and possibly valve-shaped holes in your pistons. The head is gonna have to come off either way. Then you'll be able to see the valves and can check out your lifters and cam lobes.

 

[swathdiver]

He could get a bore camera and have a look through the spark plugs but it's probably time to pull the heads.

 

[iamdub]

A bore camera would be fun to use. But, what's been damaged is surely deeper than the head. I'd save the time and cost of the bore camera and remove the head to see it, the pistons, lifters and lobes in real life.

 

[BurTan67]

im not sure myself on the compression specs but you should get a ball park avg from the good side of the engine. 0 compression is a bent valve and or other damage.

I believe I found the issue. My hp tuner was showing cylinder #1 misfire. I performed a compression test on that cylinder and OF COURSE no PRESSURE what so ever when I Cranked the motor. I tested the rest of the clynders and they all were hovering around 180 or so. But #1 would not even flinch at all. So looks like I get to pull that driver side head off. Thank you all for the great information.
Chris

 

[OR VietVet]

With an 09 I, if you plan to keep the rig, would take both heads off and have them gone thru while you have it apart. Good headsets will have valve seals and and complete rest of kit like this: https://www.rockauto.com/en/moreinfo.php?pk=1400073&cc=1442911&jsn=2301 and do the head bolts too, 2 sets: https://www.rockauto.com/en/moreinfo.php?pk=5024643&cc=1442911&jsn=2307&jsn=2307

I can spend other people's money easily but if only do one you will likely regret it later.

 

[BurTan67]

With an 09 I, if you plan to keep the rig, would take both heads off and have them gone thru while you have it apart. Good headsets will have valve seals and and complete rest of kit like this: https://www.rockauto.com/en/moreinfo.php?pk=1400073&cc=1442911&jsn=2301 and do the head bolts too, 2 sets: https://www.rockauto.com/en/moreinfo.php?pk=5024643&cc=1442911&jsn=2307&jsn=2307

I can spend other people's money easily but if only do one you will likely regret it later.

I hear what your saying. But It wasn't that long ago I did my DOD delete kit. 3 years ago. During that time Ive only used the truck on the weekend but you may be right. Just to pull both sides off. Ill pull off the driver side and go from there.
Chris