Cleft_Asunder

iTrader: (1)

So when I bought the car, the previous owner had gotten into a small accident (hitting a rock) which resulted in the bottom front-left motor mount and bracket being broken and a damaged oil pan. After buying the car, I fixed everything and still could not fix the clunk that was present in what sounded like the engine itself. I even did a trany swap with no improvement so I put back my original trany and overhauled it.

Still puzzled, I noticed a slight wobble on the crank pulley, but Ignored it for many years, but now it's become much worse. It wobbles mainly up/down and I suspect a problem with the bearings on both sides of the block. So can I replace the bearings/seals without removing the engine? And if I'm under there already, what else should I replace? (i.e. Rings?)

mikey1

it could be the pulley/harmonic balancer itself, and nothing to do with the crankshaft

the rubber can wear, and when that happens it will wobble,

if that is the case you should replace it as soon as possible, running the engine like that can cause damage to your crank bearing surfaces

ezone

I can't hear your noise from here, but since you say the pulley wobbles......

I'd inspect and probably replace the harmonic balancer (the crank pulley) FIRST.

See if that takes care of the wobble.

If it does, then I just saved you about *punches calculator* $2 grand? Send me half of that and we'll be friends.

I've seen several that separated the outer pulley ring from the center hub (simple replacement), and several that got damaged from running with a loose crank bolt (not so simple).
On the few that had the pulley run with a loose bolt and suffered damage, a couple of those (technically) should have gotten the crank replaced------ but lived just fine without.



Those engines tend to develop some main bearing rattle at high mileage too. Not a big deal most of the time.

Cleft_Asunder

iTrader: (1)

Well, that high mileage rattle (subtle in mine) is what made me do something stupid today. Now normally I research stuff and do a good clean job fixing whatever, but not this time. I didn't want to think today so I decided to put all my faith in some guy on youtube. It seemed so easy when I saw the guy do it right on the video, so I did the same; I pulled the plug wire off each cylinder one at a time while the engine was on. Once I got to no. 2, the engine stalled and now the engine turns just fine but no spark on any spark plugs. I hope my ignition coil didn't go...

This was the vid btw. That's exactly what I did.

ezone

Your coil died.
"Died on the operating table", as it were.

I've done it myself, and even did it to a customers' car in the shop for an unrelated issue. Hard phone call to make, ya know?


If it failed like this-- it was near the end of its useful life anyway.
Be happy this didn't require a tow truck to get you home, and a bunch of time to figure it out.
Seriously.




Read your answer apparently before you added the video link. Clicked REPLY and suddenly there is a video that wasn't there a second ago.


Good demo of how to check and isolate noise to a single cylinder, if it is caused by a single cylinder.

In this case the bearing isn't completely gone.
When the bearing is completely missing from the bottom half of the rod (cap), the piston can contact the cylinder head and make more horrendous noise. In that case the noise does change, but does not go away.

Cleft_Asunder

iTrader: (1)

Right as usual ezone. Not a single plug fired so I swapped the coil, and the new coil fired the car in less than a second. (my car was cranking a bit slow) I put back my old coil and nothing. I wonder if a weak coal effects gas mileage, because I'm meticulous on tune-ups and despite having a steady 720rpm, I've been suffering poor gas mileage compared to the past. Maybe 100k is a good change interval for the coil. (I've got over 155k on the original that just fried)

Cleft_Asunder

iTrader: (1)

But why would that exact test cause my coil to fail, because it was weak?

Regarding the video: Why not do the test by removing both fuel injector plug and spark plug on X cylinder? That would remove combustion.

ezone

The death of this coil is not the likely cause of poor gas mileage.
Did the engine shut down while driving under high ignition load/demand?
No. Not the probable cause.

IMHO



The high voltage demand caused by pulling the plug wire off the plug (widening the spark gap to the point that spark no longer zaps nearby metal, thus causing maximum secondary voltage output) caused the spark to seek the next easiest path to ground.

In this case that is -- passing through weakened insulation layers covering the coil (transformer) windings. Probably arcing right through the side of the coil directly to the metal shield or to the iron core. Pry that shield off the old coil, you might find a whitish area.
Disabling either spark OR fuel will stop combustion. No need to do both.
Plug wires are fastest and easiest to reach. Injectors are usually harder to reach, and time consuming. Sometimes time is of the essence.