Help us help you. By posting the year, make, model and engine near the beginning of your help request, followed by the symptoms (no start, high idle, misfire etc.) Along with any prevalent Diagnostic Trouble Codes, aka DTCs, other forum members will be able to help you get to a solution more quickly and easily!
Your observation of the marks being off by less than a tooth is correct. It has not "Jumped" time. A stretched chain will cause all valve openings and closings to be, slightly, retarded. This can cause a the rough idle. That being said, based on the cranking video, I would jump straight to the number four cylinder and check compression. I am imagining a scenario of an over heating bearing, splashed with some oil, would cause your burning smell. As Noah stated, the cam can snap. I have seen snapped cams, right at a bearing, due to clogged oil passages (severely neglected oil changes/sludge) If it did snap, cylinders after the break will shown by compression.
"Knowledge is a weapon. Arm yourself, well, before going to do battle."
"Understanding a question is half an answer." I have learned more by being wrong, than I have by being right.
i do a compression test on every vehicle i touch ive been a DIYER for over 40 years it lets customers know the condition of their engine and where potential problems are
JeremyS10 wrote: Any suggestions on the timing chain and gears? I got the tensioner from GM. I've read in multiple places not to mess around with that, and get OEM. But aftermarket chains and sprockets are ok. I've heard horror stories.anoit Cloyes, and I don't know anything about Sealed Power, or Melling. Are they good quality?
I went to AutoZone and O'Reily this evening, they're out of stock on everything. I'm gonna have to order them, so they'll be in likely mid next week. I'm going to put it back together, and the compression test will immediately follow. I will post the results as soon as I have them. Thank you for the help guys.
Just a side note. Depending on the oil cap location, you might be able to look inside and see if the cam is turning, or not, without taking anything apart.
"Knowledge is a weapon. Arm yourself, well, before going to do battle."
"Understanding a question is half an answer." I have learned more by being wrong, than I have by being right.
On this truck you add oil to the same tube the dipstick goes in. It's a small tube that comes up from the back of the motor, and gets bigger at the top for the cap to attach to, and the dipstick is attached to the cap.
I would go ahead with the compression test with the stock gears and chain. It hasn't jumped time . I kind of suspicion a broken cam from the sound of that cranking video in which case it would be a waste to change gears and chain. Unless I am mistaken you should be able to take that compression test even with the timing cover off of the engine start at the back cylinder if it dont have compression or compression Is very low them go ahead and pull valve cover but I wouldn't put more parts in it till you have found problem . You may be replacing the motor if there's to much damage.... but that's all speculation compression test first!
I went back to the begining and checked out those pics again.
Pole is right, those marks aren't as far off as I thought they were when I first read this on my phone.
I'm really interested to know what the compression test results reveal!
Ok, compression test done on cylinder 1 and 2. Number 1 reads 70 psi. Number 2 reads 30 psi. I don't think doing 3 and 4 is really necessary, as I think 1 and 2 tell me enough. If I need to, I will, but my battery is dead, and number 4 I don't think I can even get to. Also, number 2 didn't read anything for about 5 seconds of cranking. Finally went to 30.
How does this spark plug look to you guys? It has maybe 2000 miles on it. It's about 5 months old, and I pretty much just drive to work and back, which is about 20 miles round trip.
Yikes! Something terrible happened in there for sure.
Here's the video I mentioned before showing how to perform a cylinder leakdown test.
If you have an air compressor, you may be able to rent the leakdown tester tool at a local auto parts store.
Of course, if you don't want to sink any more money into this engine, then there's really no need to do the test.
I don't have an air compressor. And test after test seems to yield no results, just gets me closer to the next test. I watched a video about leak down testing, and the guy said if it's in the top end, repair, if it's in the bottom, replace. Since I still have no idea what's wrong, and I've done all the tests I can, I guess that's a wrap.
After all you've been through, I would be interested in having a peek under the valve cover. Watch things move, or more to the point, NOT move. THEN call it a wrap.
"Knowledge is a weapon. Arm yourself, well, before going to do battle."
"Understanding a question is half an answer." I have learned more by being wrong, than I have by being right.
pole71 wrote: After all you've been through, I would be interested in having a peek under the valve cover. Watch things move, or more to the point, NOT move. THEN call it a wrap.
Yeah, I might as well. Since I'm gonna have to replace the motor I'm sure, why not take it apart and see exactly what's wrong, if I can. Thank you guys for your help. I appreciate it. I will update you on what I find.
What a buzz kill, like closing my eyes at the scary parts. All the way to the point of calamity without conformation. At this point the story can still go the other way and have a happy ending. Maybe compression was low from cylinder wash from all the cranking. Or maybe I just prefer happy endings
No happy ending. The truck is sitting there, rotting away. 3 grand worth of new parts, useless. I'm probably going to tow it to the warehouse I work at, and part it out. Or not. At this point, I really don't care. Kinda just want it gone. I figured my HOA would've had it towed out of here by now. But nope, there it sits.
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