99 Monte 3100 Ran Low On Oil - Lifter Collapse & MUCH More HELP

[smith1090t]

Hello,

I'll try to make a long story short, but since it's so cold and snowy out, and I use Full Synthetic oil, it had been about 7K miles since my last oil change and I had not checked my oil level since. I was aware of the oil leaks on my car but I didn't really put two and two together. Discovered upon starting the car 2 days ago a loud and terrible rapping sound, I'm almost positive it was collapsed lifters. Added oil and ran the car over an hour, the rapping noise since when away, but a hard misfire on cylinder 3 still remains, along with a strange smell from the exhaust which smells like a combination of sulfur and something else, not directly smelling like burning oil, but the smoke certainly seems more dense than normal condensation would.

I can also hear the miss puffing in the intake of the car, and I'm not sure if its normal but I can feel some vacuum on the dipstick tube of the car, and when the dipstick is removed, the engine idles pretty high. The only code that ever came up was a cylinder 3 misfire. Still every once and a while a knock/rap or some sort of noise does come back, particularly in higher RPM's.

I'm overall not sure where to go from here, I've tried unplugging each plug one by one and seeing if the noise changed (back when it had a constant loud noise) and none effected it, so it sort of confirmed my suspicion of a top end problem. It also seems like the engine is really hard to turn over when cold, to the point where my so far so good battery needs a boost from a spare battery I have around. I have videos of the noise before and after adding oil (took me a bit to find that it was low, didn't expect it).

I'd have no problem replacing the lifters myself, but for some reason I do fear messing with the cam or anything deeper (heads etc).

I see no point in doing a compression test, cyl 3 is obviously dead, and it seems to me from the intake noise that its the intake valve that has a problem.

 

Today I ran the car for about 15 minutes and I can definitely say it is now burning oil, I can't really smell it, but I can see it in the exhaust smoke. The knock is intermittently there, the miss remains constant and harsh. I'm now wondering if I have a stuck or bent valve on cyl 3, and that maybe it actually chipped somehow and the dislodged piece rattled around in the cylinder and scored it all up causing a bit of oil to be able to be burned up?

I plan on removing the rear valve cover tomorrow weather permitting.

PS: And just to eliminate any doubt in future questions, this is an 86,500 Mile car, and it ran absolutely perfectly up until the oil got low. And if this turns out to be just lifters, I'm thinking I'll replace all 12 and swap on 3400 UIM and LIM (already have a 3400 TB on it) and possibly getting a cam & tune!

 

Thanks for any and all help guys!

 

[Schurkey]

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