This thread is about the 5.3 I just pulled from my truck. It was a great running engine with 78K miles. I will be selling this engine to help pay for the 6.0, but first want to make sure it's good to go. One of the spark plugs removed from the engine led me to do a leak down test on the engine. The rings are holding good pressure, but several valves were leaking, one in particular. So both heads are off, everything decarboned, valves lapped, new valve stem seals, new head gaskets, and new head bolts. I got almost everything cleaned up tonight. I've got one one head left to clean/lap. I should be able to pick up the parts at NAPA tomorrow and have it all wrapped up by the end of the day tomorrow.

I also removed the Comp Cams XR265HR and put a stock LQ4 cam in it. It's close enough to the original 5.3 cam, the PCM should never know the difference. That's all buttoned up and done.






All eight cylinders are nice, with all still showing cross-hashing.








So what is all this junk on all of the exhaust valves? I'm suspecting the tune was lean.

 

Well, I found the root of the problem on the one cylinder leaking on the intake valve so badly. I was putting the valves back in the head, and that particular intake valve would not slide in freely. Turns out the valve guide is broken in half down in the head. So much for finishing this project today. I'm just glad I found the source of the problem. I did get the other side all buttoned up, and everything else cleaned up and ready to go.

 

It's all back together except for the coolant crossover. I need the bolts.

What's a fair price for this engine? It's all there except for a few of the sensors, dipstick, and oil adapter plate above the filter. 78K miles, had nothing but synthetic since 20K, 55 PSI hot idle, completely decarboned, valves lapped, new head gaskets and bolts, intake cleaned.