So in 2010, I bought a 2000 Chevy Tracker, with a 2.0 DOHC 4 cylinder. (some of you may remember it, I posted some pics).
I drove it about 5000 miles, and it died on the wife one day in traffic mid-October. She thought it ran out of fuel. No noises or anything when it quit. I put fuel in it, went to crank it, and noticed it sounded "hollow". Tore the valve cover off to discover a broken upper timing chain, and a chewed up sprocket on one of the cams. Knowing that it's an interference engine, I let it set while I worked on funds to replace the engine.
March of 2011, I read somewhere on this forum where something similar happened to a guy, and he was able to replace the upper timing chain, and everything was good. It seemed plausable, since when the upper chain lets go, all the valves close at once--lowering the possibility of valves kissing the pistons. I bought a complete timing set off of ebay for $90 (both chains, all 4 sprockets, both tensioners and guides), thinking that even if there was damage, I'd want a new timing set on a used motor anyway right?
I put the timing set on, and tested compression. 199psi across all 4 cylinders! (factory spec) I slapped it back together, and she ran great. A little noise at startup, but nothing I was concerned with.
I drove the heck out of it, and after another 4000-4500 miles, I put 4 brand new tires and a new radiator in it. (old rad had a hairpin crack that was leaking) I drove it maybe 2-300 miles after the radiator, and one evening it lost all power and died (in the exact same intersection that it died for my wife). I cranked it, and heard the familiar hollow sound. I called up a buddy, and he brought his Excursion and towed me back home. I pulled the valve cover, and it was like I went back in time. The exact same thing happened! (although it looks like a chain link stretched apart, rather than just exploding)
Being pissed at the thing, and not knowing what I wanted to do with it, I let it set all year. I read the thread on here where a guy did the same thing I did, and bought the $90 complete timing set off ebay, and the exact same thing happened to him. He bought quality parts, put his back together and has been smooth sailing ever since. After reading that, I bought the same high quality parts he did, and put them in. (PCI from partsdinosaur.com, For sure better quality--thicker sprockets, thicker chains, etc...) After getting her back together, she runs, but has some nasty noises going on. I think it's bent valves, but a few people I talk to don't.
Facts:
-Very noisy at idle
-Runs great!--I've driven it 100+ miles since putting the new timing components on
-Seems to have plenty of power (hard to tell after driving the V8 Jeep)
-Accelerates well
-I left the valve cover off for 8+ months, so the cams and valvetrain were open to the elements under the hood for that long
-noises appear to be coming from right inside the intake manifold-area of the head
I drove it about 40 miles and took a video. Then I poured 1/2 quart of Lucas stabilizer in there, and drove it another 40-50 miles, and took another video. Today when doing a complete oil+filter change, I noticed that the noises seem to disappear around 2500 rpm and up. (see 3rd video) (note, it has 4.88 gears and runs 3000rpm|removethispart|@70mph)
Here's the 3 videos. Notice how you can't even hear it in the cab. (not sure how to embed on this site)
https://www.youtube.com/watch?v=9--a...3&feature=plcphttps://www.youtube.com/watch?v=s8lv...2&feature=plcphttps://www.youtube.com/watch?v=N2OX...1&feature=plcpWhat do you guys think? Bent valves? What boggles me is that it idles smooth, runs good, has power, but sounds like a diesel. (it shouldn't sound like a diesel)
