Harmonic Balancer Snapped

I have a 1999 Toyota Tacoma 2.4L XTRA cab 2wd has about 130k on it. The harmonic balancer snapped and completely stopped working. After a few attempts by someone else to drive it once no oil was pumping and the engine overheating. It came back to me.

Any suggestions on what damage may have been done or what I should do. The mechanic who took it apart said the oil pan needed to be replaced because metal from the balancer breaking went into the oil pan.

Long story short I am not paying the mechanic to replace this stuff and was wondering if anyone has had any similar problems or had to do anything similar. Any suggestions would be appreciated.

 

No oil pressure will ruin the crank and rod bearings. The motor needs to be rebuilt or replaced.

 

How does a balancer snap. I have seen them crack or shear woodruff keys. Could he put a new key and pulley on then check compression ect?

 

Mechanic sounds like an idiot. How would any part of the harmonic balancer get into the oil pan?

I've heard of the outer pulley separating from the inner part because they are attached by rubber, then the outer part stops spinning and the water pump stops spinning. Or like Adude said, the key can break, and if the bolt is too loose the harmonic balancer will not spin.

You need to take things apart and assess the damage for yourself. Posting some pictures of the damage here would help and be interesting to see.

If the engine overheated badly then you could be looking at a warped head and blown headgasket.

If somehow the oil pump got damaged (behind the harmonic balancer) and oil wasn't pumping, then this engine is toast (as Peter Venkman might say).

 

Maybe he meant the oil pump looks like he took that off and didn’t give me the part back that’s what he said when I called and asked. He’s a idiot.

How do you tell if the engine needs to be rebuilt? I’ve heard these engines are pretty tough. Not saying that driving while no oil is pumping is a good idea but just wanting to see if that parts necessary before dropping a bunch of money.

 

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If it were me, I would pull the valve cover and remove the camshaft. This would tell me if the engine starved for oil. A better tell would the the crank bearings, but that is more work to remove the crankshaft.

If the vehicle were driven any distance, the engine would have likely seized with no oil distribution to the engine.

EDIT: that is a very strange way for the balancer to fail. Was somebody working on the motor?

 

The timing chain was done a long while ago other then that no work on the motor.

It was driven for a while after it failed apparently. Not quite sure how it happened.

 

Wow! I'm not sure how that could happen. I almost want to say that someone broke it trying to remove it with a crowbar or something, like if it were stuck from gummed up oil. Maybe they didn't realize it extended that far back on the crankshaft and they hammered a crowbar behind it.

Try to get the oil pump cover back to see if there's any damage on that.

If it did crack apart like that when installed it would have chewed up the oil seal on the oil pump cover. The harmonic balancer surface slides on the oil seal. This would have caused a significant oil leak, so it's possible the oil went low. The oil pump gears look intact though.

Taking the exhaust cam off to inspect the cam bearings is a lot easier than taking the intake cam off. The intake cam has the chain on it. If you take the exhaust cam off follow the procedure in the repair manual and be sure to install the service bolt in the gear.

Or you could put the oil pump cover back on and a new harmonic balancer and try to fire it up.

 

Guy said that’s how it was when he took it off he’s a piece of shit though. He casually offered to take it off my hands if I didn’t want to pay 2200 to repair it. Fucker

 

Would be cheapest to replace with a remanned motor.

 

It's unusual for sure. I think if someone pryed it the damage would have been closer to the pulley, so maybe my theory is wrong.

My next theory is that the bolt was loose and the harmonic balancer was wobbling slightly, so eventually it got a stress fracture and that piece broke off.

What's the story, you own it but someone else had been driving it?

 

Correct someone was borrowing it when it broke.

 

Know this is an old thread…………but I just discovered that the exact same thing happened to the HB on my 3rz……….

Aside from popping the pump cover (as I’m replacing the entire pump assembly anyway) to assess damage, does anyone have any input on where to go from there?

 

Guessing the bolt wasn’t torqued down enough and wobbled out over time………….

Not that I shouldn’t have noticed this occurring myself, and am also not a mechanic by any means……..but this truck was purchased from individuals with blind overconfidence in their mechanical knowledge/abilities, who also certainly lacked an attention to detail, based off of numerous other, unrelated, findings…….

 

Oh my!

 

Give us a picture of the woodruff key in the crankshaft. I sure looks like the balancer break started at the keyway in the pulley.
Dump the engine oil and see if it is glittery, if it is the motor is toast. If the oil isnt glittery take the oil filter off and drain it in a clean container and check for glitter there. Cut the oil filter open and pull the pleates apart and look for glitter in the filter media.

 

Its like those dreaded lower ball joints....if you're driving around on an original HB
you're on borrowed time

If its been replaced with some cheap aftermarket one......you're on borrowed time

its worth checking for that wobble while under the hood with it running....
or the alternator belt starting to slip/whining


when they wobble too much....it causes that bolt to back off
all hell breaks loose after that.....damage to time cover on inside where the oil pump gear rides....oil pump....worst yet sheer woodruff key/and or wallow the key seat

Not sure about 5vz.....but on 2rz/3rz they can cause a lot of damage if not caught early



my 400lb paper weight

 

also
take valve cover off
inspect cams for oil starvation.....look for 'rainbowing' from heat on lobs

top of engine will take a dump b4 the lower end does just bc oil will not be moving up to the head
ugh sorry