'93 Del Sol Si, D16Z6

Today as I was getting home, I noticed a loud, rhythmic knocking noise coming from my engine. Popped the hood, and it looks like my crankshaft pully / harmonic balancer is wobbling. I got under the car and tugged on it, and I was able to rock the car without noticing any play in the pulley.

Need to get the car fixed ASAP, won't be doing any driving until fixed as I don't want to cause any damage.

Any ideas what this could be? Bad balancer?

 

Stop driving the car until you check whether the crank pulley bolt is loose and whether the metal key is present or missing.

 

Update: Pulled the wheel off the car and got a better look at the pulley; definitely loose, could rotate it back and forth by about 5 degrees without the bolt turning. Got my basic ratchet and was able to tighten the bolt by a fair bit, car no longer makes noise and pulley doesn't seem to wobble when running. Yes, I need to get a torque wrench and get it to spec, but all I've got is a ratchet at the moment, so I just tightened it as much as I could.

Does anyone know the reason that the bolt may have come loose? Improper re-installation after the previous owner replaced the timing belt? Excessive engine vibration?

Also noticed that one of my engine mounts is shot, but that's a problem for another day .

 

Get a 25" breaker bar. The crank bolt needs to be crazy tight.

 

The crankshaft pulley should be snug right up until the point it comes off the end of the shaft, and have no rotational play whatsoever until the key leaves the channel. If you have any rotational or "wobbly" play in it with the bolt loose, your pulley, key, and/or crankshaft end are completely shot. You'll never be able to set your timing correctly.

Improper torque, usually. The threads of the bolt are supposed to be oiled to prevent seizing from friction while tightening, like any high-torque assembly, and if it's not up to spec it'll come right off, even though the engine rotates in your favor. 134 ft/lbs.

 

Damn, here's to hoping it's just the pulley... I've never done much legitimate engine work, mainly just replaced components, master cylinder, etc. If the crankshaft itself is damaged, how much work does it take to replace? Would it be possible to do without removing the engine, or are we looking at a serious procedure?

 

It's a legitimate bitch. You have to take off the transmission, the lower exhaust, the oil pan, the crank pulley on the front, the dust cover, the oil pump, the flywheel, the rear cover plate with the main seal, then the internals in your way to the crank. This image claims to be for a d16z6, but the bearing cap bridge doesn't look right. It's close enough for this post at least to show you what you're dealing with. Get your FSM.



It's doable, but the main issue is going to be reaching everything on the side for removal with the bay in the way, and then working with a rather heavy crank against gravity when you go to try and put things back in.

 

Take off the bolt and make sure the keyway is in the crank snout which holds the harmonic balancer onto the crank.

The crank pulley is behind the harmonic balancer. As long as your timing covers are on it should not come off unless the harmonic balancer comes off

 

The crank pulley and harmonic balancer are 2 different things. I think you got the lingo wrong in the first paragraph

you can see the groove in the crank snout where the keyway sits to hold the balancer in place so it spins with the crank pulley

 

That is the timing belt drive pulley, not the crankshaft pulley, despite being on the crankshaft. The harmonic balancer and crankshaft pulley monikers are interchangeable since they're integrated together.

 

Well folks, I come to you today with a heavy heart. She's done for. Keyway in camshaft is mangled, no chance of her running without a rebuild...


I guess I found my new project

Thanks for all the help, I really appreciate it.