95 GT shaking VIOLENTLY, now will not start

BlackSNGT

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Jul 28, 2021
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Ukiah
Ok so... first off, i've looked for answers.. and I have a good idea what's going on... that said.. i've never had this happen before over the course of 12 previous Mustangs...

Stock block 331, forged internals, Vortech S trim with AFR 185's, blah blah.. anyway..

Coming home about 2 weeks ago, going maybe 35 or 40 mph, shifted from 3rd down into 4th.. soon as I let the clutch out... BAM... the car started shaking more violently than i'd ever felt before.. like wow.. like I was off roading all of a sudden.. car died.. I popped clutch and limped it another 100 yards and turned off before stopping..

Nothing visible.. no oil leaking.. nada. Tried to start it, seemed like it was siezed... now...

About 2 days prior to this, I had changed the oil... I have a 7 qt Canton deep pan.. then obv the filter, and the S trim... I put in around 8 qts.. I KNEW it would be a touch low.. as the dipstick isn't the bet indicater on this thing.. but hey.. 8 quarts til I can get it up to grab another one!?!?

In any event, it surely seems like the motor seized on me.. or I threw a rod.. i'm unsure at this point. I thought the clutch let go but pulled tranny and it all looks fine.. rear end rolls free.. and motor spins free but seems to make a funny loud TICK noise every few seconds when trying to start it...

ARG.

Anyone been through this? Did I maybe snap a camshaft? I'm not abusive.. the car has been a 3+ year project and i've spent a ton of money, and had everything done properly at machine shops, etc.. very disappointing...

If it matters, the rotor in the dizzy won't spin. It's locked in place. I hope this bish didn't spin bearings... arg...
 
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Definitely sounds like a mechanical issue. That definitely sucks.

Really, not much we can suggest here other than various things to check. Did the balancer spin?

Can you pull the distributor and see if the cam is turning when you turn the engine over? Timing chain failure perhaps?
 
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If the engine shook badly stopped dead, and wouldn’t spin when it was hot, but now spins when it cold, you have something broken that expanded, and caused things to tighten up as a result. My guess is a cylinder, maybe the block itself. There would be water in the oil, and with fresh oil, it is probably sitting on top of that oil. Drain the oil, and see what comes out.
If there is no water in the oil, but you hear a clicking noise while cranking, that is probably some piece of something striking something while it’s going through the rotation. Either way, that engine is going to have to come out.
 
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Sounds like an issue with the timing chain/set or camshaft to me, especially with the engine turning over but the distributor not turning.
As others have said, it's time to tear into it.
 
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Sounds like an issue with the timing chain/set or camshaft to me, especially with the engine turning over but the distributor not turning.
As others have said, it's time to tear into it.
Well, I just heard from the guy doing the work.. and yep. The bolt holding the timing chain in place worked it's way out somehow, and kaboom.. it came off and fugged stuff up. He said it sheared the bolts and front cover off the cam, and did a little damage to it, but it looks saveable.. I only had to go a few hundred feet but I know that's an eternity while this is going on..

He is scoping it now to see if I bent any valves or dinged up any pistons... blah.

Least it wasn't seized lol.

Next question... if the cam is damaged.. and i'm not really sure "what" cam is in it.... how do I proceed to replace it with the same thing??

I imagine there will be a part # somewhere on it? I have a quarterhorse tuner, and have a guy remotely tune through my logs and live as i'm driving it.. I had it set up really nice, and i'd love to not fugg with it anymore. It was about perfect and i'd love to do the same cam.

Thanks!
 
Hopefully you'll get away with minimal damage.

As far as the cam, that may be hard to figure out. Many manufacturers will have a grind number or part number on the end. Some won't, and if it's a custom cam then all bets are off.
If it needs to be replaced, look for part numbers and go from there. If there are no numbers, you can try to measure the lobes and see if it matches with any manufacturers specs.
 
Was it gear drive or timing chain? I've heard about gear drives breaking bolts and also chipping gear teeth, even breaking the cam, hopefully no more than a few valves bent worse case.
Keep us posted.
Oh, BTW, if you can't ID the cam this may be a chance to put in a known cam that matches the rest of the setup.
JMO
 
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You got lucky. I had a friend who had the same failure, and for lack of a better term, the block exploded. Nothing could be saved.

Kurt
 
Ok so now mechanic wants to take oil pan off/lift motor...what for? Cam looks ok...
20210812_110132.jpg
 
Why take off the oil pan? If something broke, it will usually end up in the pan. Sparkles in the oil mean that some of the bearings are failing. At this point, you're probably looking at a full tear-down to find out went wrong. And I would recommend a full rebuild just to make sure there are no hidden problems inside.
 
And I just can’t imagine that if the timing chain stopped turning while the bottom end continued around that there wouldn’t be all kinds of bent valves, but maybe these engines aren’t interference with stock or small cams.
You can see a girdle on the main caps, i’d expect it to have an aftermarket cam with enough lift to be of concern.
All a valve had to do to get bent was touch the piston..scoping may or may not show that.
there is stuff in the pan, when the bolts sheared, that’s where it went..I’d do more than just remove the pan. Theres no way i’d just throw another cam and timing chain on this and call it done
 
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I agree. If the bottom end kept spinning and the camshaft wasn't, I'd be amazed if a couple valves didn't kiss a couple pistons. These engines are interference. I'd be pulling the engine apart and checking everything after a timing chain failure like that.
 
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And I just can’t imagine that if the timing chain stopped turning while the bottom end continued around that there wouldn’t be all kinds of bent valves
I agree. That's probably the ticking noise when cranking. Scoping isn't going show much unless they're really bent. Leak-down test is the way, plus it will tell you which side is bent based on the location of the leakage air noise / flow (intake side, exhaust side, or crank case).
 
Lost a timing chain (gear blew apart) about 20 years ago on my T-Bird 302 (1984 non-HO low-compression non-roller so not the same thing entirely) and the pistons hit the valves hard, all of 'em. Pushrods were all kinds of interesting pretzel shapes, but the pistons were undamaged. I ended up replacing the valves anyways since I had the heads off to inspect everything (no $15 borescopes back then) but none appeared bent on removal (they could have been damaged enough to lose compression, just visually seemed ok). So while this is an interference engine, the pushrods are the weakest-link by-design so there's some small but not insignificant chance the valves and pistons are undamaged. Check all the rocker studs / bolts too, one of mine sheared off in the process of bending the pushrod. Agree with @WhiteCobra95 leak-down test should be easy after you pull all the damaged pushrods and you don't need to replace anything until you know (a compression test you'd need to repair everything first). Keep your fingers crossed and say your prayers, you might get lucky.
 
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