No compression cyl.#2

[CHAD5.0]

2001 with about 150,000 miles on it. I put it in used for a friend of mine back in January. Engine ran great for about three weeks then developed a miss at idle. Checked compression and #2 had about 200psi. (All others were 380-400) Been short on time until now so dug into it more tonight. Did a leak test and it appears to all be going out the exhaust. Also compression is now only about 10-20 psi. I think i am going to pull the head this weekend, hopefully just a valve issue. Any ideas what I may find or should look for?

[dray8165]

If it is just a valve issue - you have to question why that one valve was damaged. Usually, the valves on these trucks get damaged from overheating. Then you have to figure out what would cause just this one cylinder to overheat. Maybe a cracked injector tip or bad injector leaking too much fuel into the cylinder. If all your valves look bad, you may need to get a pyrometer installed and monitor your temps - especially if you tow or drive it like its a Corvette...

[CHAD5.0]

Originally Posted by dray8165

If it is just a valve issue - you have to question why that one valve was damaged. Usually, the valves on these trucks get damaged from overheating. Then you have to figure out what would cause just this one cylinder to overheat. Maybe a cracked injector tip or bad injector leaking too much fuel into the cylinder. If all your valves look bad, you may need to get a pyrometer installed and monitor your temps - especially if you tow or drive it like its a Corvette...

Got the head off last night, exhaust valve was cooked (It was #4 that haa no compression not #2). Exhaust valve on #2 had some nicks out of it also. This was a used engine that I put in for a friend, I told him not to put his programmer in until he got gauges, he didn't listen. He pulls trailers all over the country with it, got out west in the mountains and didn't like the power so he put a 40hp superchips progam in. He told me last night that he pulled a long uphill grade (10+ miles) and after that it did seem to run the same to him. My theory is he got exhaust temps way to hot on this pull and did the damage. Hoping this is all he hurt, I guess time will tell.

[dray8165]

Well - better than a cracked piston or broken ring...

[CHAD5.0]

Originally Posted by dray8165

Well - better than a cracked piston or broken ring...

Definately easier to pull a head than the engine again.

[ju015dd]

how hard is it to pull a head on these trucks when motor is still in truck?

[dray8165]

Other than the fact that they weigh over a hundred pounds... not too bad. Of course, on your rig, you'll probably have to use a ladder...

[CHAD5.0]

I pulled the drivers side in about 2.5 hours last night. i think the passenger side will take a little longer. Good idea to have a cherry picker available.