1987 Ford 302 here, about 200k miles... it's actually a van, but not a van-specific issue and the van subforum doesn't have a lot of engine folks.

I had a screeching and knocking noise suddenly, coming out of a steep downward drive. I drove it very slowly, for a few blocks, to get where I could work on it.

I realized I had no oil. Well, not much. She leaks/burns through oil periodically I got into the habit of just adding more, but I've evidentally been negligent. I thought the stick was still reading at the bottom and maybe that was just splash. It took 4 qts. And it was dirty enough after that that I changed it all anyways. This happened twice before but I heard the lifters chattering first. Yeah, I'm a terrible person who doesn't deserve a car.

However, I did check the mechanical oil pressure gauge during this, when I first heard the screech pulling out of the drive. 40 PSI. So, I'm not even sure it WAS oil starvation or "just broke" here. I mean it's got enough miles that it's earned its death if it wants to go. I suppose the oil sump could have gone dry on the downslope and already caused a problem before I reached the bottom of the drive, heard it, and read the PSI.

After that, sometimes when I start it, it makes a screeching sound for a few seconds, then a knocking sound for a short while which seems to be in sync with the engine's rotations, but that goes away then it drives JUST FINE. Or other times it starts and runs just fine. I haven't done it enough to discern the exact pattern. It has made the noise after sitting overnight, at least.

Upon research, I suspect I spun a rod bearing. That would be the swishing sound as it spins, then it catches and stops and the knocking is the piston aligning poorly. But my question is, if it goes away after ~20sec, is it still plausible to blame the bearing?

Because I also had a problem that accompanied this right afterwards, where the car just screeched and never turned over on SOME starting attempts. Then the starter spun freely. So the ring gear is missing a tooth, the starter bolts look tight to me. Which if the engine didn't want to turn, that could happen. Or the Bendix on the starter is stuck or worn.

Should I just assume the ring gear chipped a tooth because of the rod bearing's resistance to turning? Or could these two problems be somehow connected, the sound has to do with a ring gear problem? I don't see how. If the starter Bendix failed to retract you get a loud whirr when the engine starts turning, this wasn't like that. I suppose if the ring gear had a BENT tooth, it would come around a make a knock periodically, but they don't normally bend and that problem wouldn't come and go, nor would it explain the initial screeching sound.

I have a wrench to turn the crank if it gets in a position that the starter can't catch the ring. Is there any chance the engine will remain driveable? The knocking noise always goes away within a few seconds. Then it purrs for the rest of the drive. And it doesn't always start with an alarming sound. So I don't know what to make of it. See, I just started it now after moving the ring. It sounds as well as it did any other time in the last 10 years. And I'm like "seriously? what's even wrong? I can't even take this to a mechanic when nothing happens." (it's hypothetical, I'd never take this beast to a mechanic again, not worth it, and their laughter is unsettling). Will it keep sound ok now that the oil's fresh? Well, I'm not really in a position to suddenly buy a car right now, so my life kinda depends on it. Sort of.

Repairs like this are too extensive for me, for a van, pulling the engine's quite difficult. I did Google a bit and saw that someone did it by removing the oil pan, but that wasn't all that helpful because the crank would still be worn.

 

I think you already know the answer man. Sorry. I have seen them drive on for quite a while, or a very short time. All you can do is keep oil in, and see what happens. Or drop the oil pan, find the bad bearing and replace it. The crank may be scored, the piston may of slapped about in the cyl, all kinds of crap may be hurt, then again, you may just toss a bearing in, and roll on for quite a while.
If you can follow instructions, and have access to tools, you can do it. It sucks working on vans though.

 

YES !

 

Well I'm no mechanic but I think your engine is pretty much done for. My guess is that you're right about the bearing and maybe also the oil pump is on it's way out and not holding a prime after sitting overnight(just a wild-hair of a guess). In any case with 200k on it any repairs short of a full rebuild will basically be a band-aid fix. My dad had a ford van that got wrecked so he got another van to replace it but the second van had a tired 351M and the old van had a good 351w so he enlisted the help of a couple friends (being pretty much flat broke at the time and not having quite enough knowledge to do it himself) and they swapped the engine and trans from the old van into the second one in a few days. However both vans had carburetors so there wasn't any EFI stuff to worry about but if you swap in another 302 it shouldn't be that bad. I would try to find a wrecked exploder with low-ish miles because they had GT40 heads and intake and more power than the E/F series got. Or just take what few hundred bucks you can get together and see what you can score on craigslist to replace the van.

 

Time to be retired.

 

Your engine is not dead. Rod and main bearing noise does not ever go away once the bearings are damaged. It'll keep knocking until it finally seizes up or blows apart. Since you said the noise stops, I think you can rule the bearings out for now.


I'd start by removing the starter and splash/inspection plate (if possible) on the bellhousing. You'll want to have a helper turn the engine while you look at the flex plate carefully with a flashlight. To me it sounds like your flex plate is either cracked/bent and the ring gear is coming in and out of contact with the starter.

You'll want to check that it turns true, and that there are no cracks on the plate anywhere. You may also want to make sure the transmission bolts are all tight.

 

Died of thirst, or dying from thirst and neglect. Time to buy another truck or replace the engine in you present truck.

 

Pulling the starter was REVEALING!!!

The Bendix gear (the little pinion gear which pops out when you turn the starter) has the far end of the teeth all chewed off. It doesn't always spring back in automatically. It's also spinning free without the motor turning!!
There is NO damage to the flywheel teeth.

So...
The pinion, she loosely broke free of the starter motor's internal gearing, and managed to go forward and turn the engine and get it going, but then the engine's spinning it making a ton of noise but not the WHIRRRRR of a stuck starter motor (ever have a starter relay lock up? well it didn't sound anything like that) Because it's decoupled from the geared motor internally. Well of course that would sound like a spun bearing, it's just the Bendix getting spun by the motor and it was never intended to go that fast and was grinding on what was supposed to connect it to the starter's internal gearing.

Then it walked down the shaft until only the ends of the teeth engaged, and it made a hell of a rattle as the teeth bounced around. Maybe there were certain teeth on the flywheel that were a bit longer and cracked against them once per rotation, I don't know. The period of knocks sure sounded dead-on with being once per crank cycle, but that wasn't coming from the engine.

That's why the starter didn't always engage, too. Sometimes it just threw out the Bendix and just spun internally without turning it. That has to be the problem, without missing flywheel teeth and the start bolted in place, if the starter motor turns and the engine doesn't, then the starter's busted up internally.

I'll know more tomorrow, when I can get a new starter. I honestly believe that it's just the starter because this wouldn't be a possible result of engine damage. And yes I'm a terrible person for not changing or even checking my oil sooner.

 

As Leadhead says bad bearings stay bad and I was about to suggest pulling the starter as I had a similiar issue with an old 302 as it turned out to be the starter drive. Change the oil and examine the magnetic drain plug for metal particules. You can filter the old oil and see if any bearing material is in the drained oil. Make sure you use a Motorcraft oil filter with a drain back valve.
As you stated 200k miles is up there but 300k is not uncommon these days.
YMMV
rikard

 

Hehehe yep, just the starter.

Today the parts store gave me a standard starter, not an automatic. The thing looks almost identical- but the mounting ring is 1mm wider. Which, no, it won't fit, but it looks like it should. I didn't understand how it didn't fit, expected it to pop in when tightened, and all I did was bust off the bolt-down point.

Got 'em to take it back, though. Had to go across town to an Advanced Auto branch with the starter I DID need.

Runs just fine. Never was any engine problem.

 

Good news and thanks for the update.

 

This is exactly why I try to analyze symptoms and do some basic diagnostics before jumping to conclusions - especially ones that condemn an engine.