I'm the owner of a 1997 Corolla with just shy of 150,000 miles on it. I'll start off by explaining that I know very little about engines.
Recently, during the daily commute from work, I heard a loud engine sound, followed by the battery light coming on and power steering gradually fading. I troubleshooted it as a failed belt or belts. I was able to make it home, stopped at the auto parts store, and purchased the three belts they had on file for this particular make and model.
I drove the car to my local mechanic, dropped it off with the three belts, and asked them to take a look at it. They dug in, determined that indeed, two of the belts had frayed or snapped, and also determined that they needed to order a new harmonic balancer. It seemed that one or more of the pulleys on which the belts ride are misaligned.
After ordering a new harmonic balancer and spending a couple nights at the shop waiting for the part, they finally were able to install the new part. When doing so, they came to the conclusion that a problem with the crankshaft was truly to blame, rather than indeed the harmonic balancer. If I recall correctly, the mechanic mentioned that the crankshaft was loose or had some slop to it. They returned the harmonic balancer to their supplier, charged me minimally for the labor, and explained that the work entailed to truly remedy the situation would cost above and beyond the value of the car. They swapped out two of the three belts that I supplied.
I, unfortunately, got none of this explanation in writing. The car continues to drive, but they had no prognosis for how long it will continue to drive. I've only driven it when absolutely necessary, and have carpooled or used our family's other car whenever possible. Power steering and the alternator are currently working. Today, I took the car to one of those drive-through oil change places for it's routine oil change, and during their complimentary basic inspection, their mechanics spotted the belt issues. Talking it over with them, it appears that, already, of the new belts that have been put on, one is off its pulley and the other is falling apart.
Can anyone explain to me a bit more of what this all means? What are crankshafts, harmonic balancers, and how do they interact with the mentioned pulleys and belts? What could have caused this, and what would it take to fix? What's going to eventually happen to the car if I continue to drive it? Is a car that is otherwise in very good condition sellable for parts with this situation, or is this engine problem pretty damning?
Thank you all for your help, and I apologize for my lack of engine knowledge.
The crackshaft is a shaft that runs thru the center of the engine and the connecting rods are connected to it (connected to pistons).
Attached to the crankshaft (outside the engine block) is a pulley (also called the harmonic balancer). It is pressed onto the crankshaft and is kept in place by a keyway. The pulley holds the belts (alternator, power steering, etc.).
The crankshaft has an internal thread on the end where the bolt is located holding the harmonic balancer on it.
If the crankshaft is bent (does not keep the harmonic balancer - pulley) in line with the other pulleys, or has too much play, your belts will wear excessively, or come off the pulley. To change the crankshaft requires engine removal and extensive engine work - easier to change the engine.
Your best bet is to check pulley alignments and see if the crankshaft is bent, or the crankshaft bearings are worn.
If you can get the pulleys aligned enough, or the crankshaft bearings changed - the car will last forever.
If it is close, you may just have to keep changing the belts frequently.
If it is way off - looks like an engine change.
Sell me the car and I can take care of it!!
I see that you're selling your car but based on what you've reported I really doubt that the crank is bad or damaged. I shredded a belt about a month ago on mine and got stranded at home so I figured I'd just throw on some spare used belts I carry in the trunk and get to work.
Prior to the belts failing, I was getting a surging sensation when taking off easy from a stop. When I started to wrap the belt around the balancer, the pulley started spinning so either the crankshaft key area failed or the balancer separated. I found that the harmonic balancer had indeed come apart. The local pats store doesn't carry them so off I go the junk yard in 15 degree weather. I found a Geo sitting on the ground but couldn't get the sucker off.....oh yeah did I tell you it was 15 degrees. 55 years old and wandering around a junk yard....oh yeah...and it was 15 degrees and windy too....what an old fool.
THEN I get a brainstorm!!!!!
I took four 10 penny galvy finish nails and drove them through the rubber at 12:00, 3:00, 6:00 and 9:00. The rubber was about 3/32" and these worked perfectly. I was able to drive each of them all the way through with good interference. The TDC reference mark is no longer valid but not that important as long as you know that it's invalid.
I know this is a bodge and for me is a temporary fix but I've put 1500 miles on it since and it runs great.....there was more to this story but I'll spare you the details.
I don't suggest you do this but it might be worthwhile to have another set of eyes look at it.
Jay in MA
Thanks again for the tips. I've listed it on craigslist and posted it on the corolland forums here.
I didn't think the pulley had any rubber on it - I thought it was made of metal.
So, part of the pulley was still going around with the crankshaft and part was turning with the belt?
It is difficult to get the bolt holding the pulley out of the crankshaft - you have to keep the engine from rotating.
I always jammed a lug wrench into the flywheel inspection window and that worked pretty good.
I also had to use a pulley puller to get the pulley off the crankshaft (it is pressed on pretty tight).
With the slot on the pulley ligned up with the keyway, it is lined up for TDC and correct timing.
The nails were a good creative way to improvise - and get you home, but not recommended for a permanent solution.