I have a '99 Malibu VIN M 3.1 that gave up on me about a year ago, and has sat in my driveway since. When I bought it 2 years prior, it was throwing a camshaft code, (got it at a great price), so I replaced the sensor, tried it 3 times. Each time, It’d go away for a couple weeks, and the code would return. Then is went out while driving home, it made a type of fluttering sound, and when it’d crank, it’d fire and jump all over the place before then stall out about 2 seconds later.
Fast forward to now, I decided to have a learning experience with my wife and kids. I pulled the engine and transmission in hopes of them getting involved with learning how and why things are done with engines. I removed tranny, sitting on the floor of garage, and put the engine on a stand. I pulled the oil pan, which has about 1/2 inch of sludge in on bottom. The engine exterior was covered with oil. Oil pan was missing a couple bolts to hold it in. I took off the front cover, the harmonic balancer bearing and race are good. Since it was throwing a camshaft code, the camshaft seemed the logical place to look. I rotated the engine around to the timing marks, and the engine is in perfect time. Timing chain has some very slight play, but according to the manuals, that’s about right. Slack goes away if you rotate crankshaft back and forth about 1" at the flywheel.
That led me to check the camshaft, maybe something went wrong there. So, I removed the intake, and with the engine in the timed position, it appears that every intake valve is closed, which may or may not be correct. But, the more interesting thing is on cylinders 1 and 3, there appears to be metal filings/flakes in the bottom of it, cylinder 2 appears normal, and cylinders 4, 5, and 6 have gas laying on the valves. I can see one of the camshaft bearings (I think) and it appears the edges might be chewed up slightly, which lends to a major concern. The other issue is when I took the rocker cover off, the pungent-hard-to-describe smell of gas/oil mix that makes your throat burn was present. The fuel on the intake appears that some oil might be in it also.
I’m kind of at a loss of where to go from here, I really don’t want to tear heads off to replace them, or replace a valvetrain (I have a problem mixing old with new, like new camshaft/old pushrods, if I have it apart, may as well replace it all, in my opinion. What I’m questioning is the diagnosis, and next steps if the diagnosis isn’t clear yet, I’m also trying to figure out what those flakes are in the intake valves, that aren’t full of some type of oil/gas mixture it seems…Attached are the pictures of cylinders 1 and 5. Cylinder 1 is the flakes, the other is the #5. Maybe this is normal looking, I don’t know. Oh, one last thing, where I can see what I think is the cam intermediate bearing the lobe there also looks like it’s been rubbed more than the rest, like sandpaper type thing, which may have been the ticking lifter. I should also mention that the lower intake gasket was in completely poor condition. Opinions/thoughts? Not looking to junk it, looking to learn about what I don’t know. Most of my limited experience involves diesel, which is a completely different animal.