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Discussion Starter · #1 ·
Ran smoother than ever yesterday, although it seemed to be a little short on power, but it's a very temper mental engine, so i didn't think much of it.

Today I had to start it 8 times before i could get it to pull out of the driveway. It just wouldn't stay running, no matter how much gas I gave it, although I wasn't purposely trying to rev it cold.

It has very, very little power driving down the road, runs EXTREMELY rough, it has a loud, deep thud sound on every engine rotation. with revving, the thudding sound gets faster, but doesn't seem to dissipate as other problems I've had in the past.

My oil's a few months old, clean as a whistle, and dead-on full, and my car has never even gotten hot.

Called my uncle and described it to him as best I could, and held the phone up to the engine. He thinks it's a thrown rod, he's going to try and come out asap and take a look at it with me.

It's had a lifter noise since I bought it, but I've been watching the oil like a hawk, and just replaced my busted temp gauge with an NOS one i had sitting in the box, but even the old gauge showed me it wasn't overheating. How could a rod be thrown under good care?

Any ideas what else it might be? I suspect I have an exhaust leak at the doughnut between the exhaust manifold and the exhaust pipes, but I don't think that would cause such problems as this one.

Thanks for your help, and I hope to god it isn't a rod. The engine was rebuilt by PO only a few years back, although I suppose that if i have to rebuild it myself, I'll learn a few things and i'll know it's done right in the end.

Any input?

Thanks
-Matt
 

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There are many things to check before tearing it down for an alleged thrown rod. Basic tuneup: new caps, plugs wires, points, rotor. Do a compression check and a leakdown test. Fix the exhaust leak. Timing.
 

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Sounds more like a spun bearing rather than a rod "being thrown". Oil would still look good even with the bearing problem. Usually will happen on a cold start-up. Ask me how I know. Don't know that a compression test is going to show anything either. If the sound is down low in the engine, (possibly listen with a stethescope or even a long screwdriver placed against your ear) you can bet it's not good. A lifter will sound more like a ticking noise. Internal lower end problems will have a deeper thud or clang. Good luck but it doesn't sound good. Tony
 

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There's no mistakeing a spun main bearing!From your description.Ouch! that SUCKS!!! :thumbsdown:
 

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Sounds like a rod bearing. Pop the oil pan off and check for the loose rod. Hopefully the crank is still OK so you can just put in a new bearing.
 

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If it is indeed a spun bearing running the engine is asking for disaster..The rod will eventually depart and likely destroy the rest of the engine...I would pop off the pan and take a look but I imagine the crank journal is already damaged enough that you can't just stick a new bearing in it to fix it.
 

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When people say a "thrown rod", what do the mean by this as it could have a few different meanings.
 

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Drop the pan and check the rod bolts (torque). Had the same thing happen to me this past fall, checked and sure enough one nut had backed off. Retorqued everything to spec and all it cost was a few hours time and an oil change. Don't drive the car until you diagnose the problem!
 

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Discussion Starter · #9 ·
Believe me, it's not going anywhere...


:(
 

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Acooljt said:
When people say a "thrown rod", what do the mean by this as it could have a few different meanings.
In my book, it means enjoying the view of the crankshaft through a hole in the side of the block/oil pan :D

OP, there should be a marked change in hot oil pressure with a bad rod bearing.

Also, an oil analysis should reveal an excess of metal (bearing materials) in the oil.

QD method is to drop the pan and look at everything.

BTW, rod bearing problems are pretty easy to tell. If you loosen a rocker arm, you'll hear a ticking noise, but it's be at 1/2 crank speed. A rod noise will be at crank speed. Once you've heard both, you'll immediately know which is which, and this applies to exhaust leaks (which appear at 1/2 crank speed too).

A little bit trickier is piston slap from excessive clearance or a collapsed skirt. The clearance usually is heard at cold start and improves, whereas the collapsed skirt makes noise all the time. It's a duller noise than a rod noise.

A mechanic's stethoscope can pinpoint the noise, as long as you know what you're hearing...

Pat
 

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So it's having a bad rod bearing?

Also, I have no idea what "OP" or "QD" mean. :p
 
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Take a short video of the engine running then post it on here for everybody to listen. Its really hard to diagnose with just words.
 

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Never thought there was any question about a thrown rod! It means the rod has
separated (thrown) from the crank! Often it results in a sizeable hole in the
lower block!
 

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Discussion Starter · #16 ·
The points slipped...

Damnit, that's like the 10th time since I bought the car 7 months ago. It makes a different noise every time...

Thanks for the help. I still have that ticking noise that i've had since I bought the car, I believe it's lifter noise. I'd like to repair it, but i don't have the know-how nor the time at the moment, it's finals week. Maybe someday i'll get my uncle to help me, he knows all this stuff.

Thanks again
-Matt
 

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Lifters are a breeze to change, wouldn't worry about it.

Also, if you're tired of those points, go with an Ignitor. $80 and you've got a solid state ignition, you never have to worry about fiddling with those points every again.
 

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I agree with Aaron. Get rid of the points and go with an electronic ignition. You will be much happier and no more messing with the points.
 

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Someone agrees with me? Wow, I'm kind of honored.
 
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