MadScientistMatt

Background: '95 Civic EX, original D16 without any very interesting modifications. Had the timing belt done about a month ago.

This morning I had the alternator light come on, followed by smoke curling out of the hood. Pulled over and saw it looked like the smoke was coming from the alternator. So, figuring the alternator could be written off, I turned off anything unnecessary electronic and limped it in to work. Now, I work for an automotive place so we've got a lift and a bunch of tools there, and so I take a look at it then and there rather than towing it somewhere. And I find that the crank pulley has self destructed. In a very weird way. I didn't take any pictures, could do so tomorrow, but here's what I found in words.

The pulley was wobbling on the crankshaft even though the crank bolt was still feeling tight, which didn't make sense. I put an impact gun on the crank bolt and it broke the bolt off in the crank. Great. I took the pulley off and my first impression, not having seen a stock D16 crank pulley off the engine, was that somebody had left out a bushing between the crank snout and the pulley as there's about a quarter inch of clearance between the pulley and the crank snout in all directions. I looked closer and there were no splines or keyways in the pulley, just a relatively smooth hole in the center.

What could have done this? It almost looks like a pulley made for another engine if the pulley didn't otherwise match the pictures of what a D16 crank pulley should look like (the previous owner had repaired the car with a couple other oddly inappropriate parts, had disc brakes of different sizes side to side). I'm guessing the key may have broken, made the pulley spin on the shaft and grind itself out from the center? Doesn't make much sense but I can't think of any other way this could have happened. I called the mechanic who did the timing belt and he insisted nothing seemed wrong with the pulley at the time. Normally I trust this mechanic with just about everything except really pesky electrical gremlins.

Now I need to figure out if the crank snout is still going to accept a pulley. This has been quite a bad day...

Former User

I recently read about a similar problem here on the forum. In this case, the mechanic apparently installed the timing belt guide plate backwards (concave in instead of out relative to the timing belt drive pulley). In your case, the mechanic may have forgotten to reinstall one of the guide plates.

MadScientistMatt

Thanks. I double checked after seeing that post, though, and both guide plates are installed in the correct orientation.

peaseapea

Wow.
Sorry about the hard luck, man.
Definitely get some photos up if you can.
Out of curiosity, when you limped it into work thinking it was the alt,
what was the car doing / sounding?

vtechjunkie

iTrader: (2)

If you get a new pulley and remove that bolt the proper way then it should be fine. If I remember right the pulley is the one with the splines,not the crank. Make sure you get that key though. GL.

MadScientistMatt

It didn't make much noise at all at first, but it then turned into a scraping sound. I thought my alternator's bearings had come apart.

Pictures of the carnage are attached. Looks like it's going to be possible to just bolt it back together using a new damper once I get the bolt out as the keyway seems to be mostly intact.

Former User

I see wear only on the outer edges of the guide plate seen in the bottom left photo, suggesting that the outer plate may have been installed backwards with concave facing in. I can't tell for sure though in the photo.

Also, where is the slot in the crank pulley where the key inserts?

MadScientistMatt

It's concave face out - I checked. It's lit from below in that photo so that may make it look reversed.

That's what I'm trying to figure out too!

Former User

There's the problem. It's an aftermarket or incorrect crank pulley lacking a key slot that functions to prevent the crank pulley from spinning on the crankshaft. You must have been unable to check the ignition timing. Purchase the proper crank pulley and key when you put it all back together.

MadScientistMatt

So that's why I had to run the distributor against the stops to set the timing... it was, somehow, in the ballpark. I was almost wondering if the keyway had somehow been rubbed off, but the more I find out about this car, the more it seems like some idiot pieced it together from a bunch of random unrelated parts that just happened to fit together. Like the brakes being an inch larger on one side than the other...

EJ2-Fluffy

iTrader: (1)

For my crank pulley, it wore down quite a bit. In fact, The crankshaft key groove was wore down to where the key and crankshaft had to be modified to fit a new key (wider and longer).

It would be that the pulley was wearing down after a while and eventually lost the groove or just chipped off.

Also, with all those metal shavings, it seems like the two guide plates may have been installed concave in instead of concave out (which was already pointed out in this post).

If the grooves are gone, no matter how tight you make the crankshaft bolt, it will keep coming lose and moving like that.

Also, it might have been that the bolt was overtightened and may have fractured the crankshaft perhaps causing an imbalance.

http://hondamarketplace.com/showthread.php?t=2426473

MadScientistMatt

Much to my relief, I was able to get a new pulley from the local dealer on there without any trouble - even got the broken off crank bolt out without an extractor. I'll have pictures up soon, but it looks like that was the correct pulley, just unbelievably worn.

Former User

I hope you also replaced the damaged guide plate and lower timing belt cover.