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1990 Cadillac Deville - Possible Seized Pulley Questions

First, to provide a little background. My sister went to start her 1990 Cadillac Deville one morning. The vehicle was emitting a very obnixous squealing sound and a very strong burning odor. I took the belt off to look at the pulleys. It appears as if one of the pulleys is seized. My first impression is that this is the water pump pulley, however, I am not certain. I have a few questions that I would greatly appreciate any help with.

  1. The pulley that appears seized (does not want to rotate by hand), is circled in the attached photo. I have also circled it in the routing diagram. I was thinking this was the water pump pulley; can anyone confirm or deny?
  2. There was another pulley (one of three that is above the highlighted one in the routing diagram) that had “shreds” of the belt on it. However, this pulley appeared to turn pretty easily by hand. Is it possible that the stuck pulley resulted in this one shredding the belt, or is it likely to be defective as well.
  3. This may be a stupid question, but is there any way to clean/repair the pulley, or is replacement the only option?
  4. Finally, while I am not an expert, it appears as it some fluid was leaking on the pulley, possibly causing its death. Based upon the location of the pulley, what is the likely culprit?

Thanks much for any assistance.

I don’t want to be insulting but your post shows me you don’t understand even the basics. You need some professional help to solve this.

If a pulley won’t turn, it isn’t the pulley’s problem. The problem is what it is attached to. The big pulley lowest to the ground is the crankshaft pulley that drives all the rest. I can’t tell from your pictures exactly what the locked up pulley is attatched to but it is significant work to replace whatever it is that is locked up.

Thanks for the response. For the record, I am aware that you replace the associated/attached component, not the pulley itself. That is, I was expecting to replace to water pump if that is what it was NOT just the water pump pulley. I suppose I should have chosen my words better, particularly point 3. I pretty much suspected the actual repair would be out of my ability. I am just trying to help my sister make a decision on how to proceed. However, if that is truly the crankshaft pulley then my question is: should I even expect it to be able to rotate the pulley by hand? Thanks.

The crankshaft pulley (AKA harmonic balancer) is the biggest, heaviest, lowest. Not turnable by hand, even with all the belts off.


That makes sense. Thanks. The car does start, but it did seem to struggle to turn over. However, when it did start, the symptoms (based upon my admittedly limited knowledge and experience) seemed related to the belt / pulleys / accessory system. That is, the loud squealing and burning smell. When I took the belt off, I noticed it was starting to tear/shred and there were little belt pieces on one of the other pulleys (not the crankshaft one that I could not turn).

I know it might not be easy to assess over the Internet, but based upon these symptoms, is it more likely that the issue is in one of the accessories (power steering pump, water pump, etc.) or an indicator of major engine trouble/faulty harmonic balancer? More specifically, are there any steps that I, as a non-professional, can take to further diagnose the issue?

For reference, the car actually shredded a belt before. We assumed it was due to poor quality work by a mechanic as the car had recently had its alternator replaced before the incident, and a different mechanic who fixed it did not seem overly concerned. Our assumption seems to have been an error.

Thanks again.

A parts place should be able to identify the pulley if you show them your circled diagram. It might be an idler pulley - not driving any component, just routing the drive belt. I had one fail and squeal on my 1999 Civic some years back.

The pulley you’ve circled in the posted photo appears to me to be the crankshaft pulley. I notice what appears to be a timing marker that sticks out directly above it, which is how the shop checks the ignition timing w/a timing light. There’s probably a notch or other sort of mark on the pulley itself. If I’m correct, the crankshaft pulley isn’t possible to turn by hand, and the fact that you can’t turn it isn’t diagnostic of anything, entirely normal.

If you have squealing sounds most likely either the belt needs replacement (try that first), or one of the other accessories is locking up (most likely is the AC compressor), or at some point a repair was made which caused the pulleys to not remain all in the same plane, aligned with each other like they should be. Improper replacement of a belt driven accessory like a power steering pump, AC compressor, alternator could be the culprit. If you can observe twisting in any of the belt segments, that might be a clue of a pulley alignment problem. With the belt off you can try turning the other pulleys, listening for weird noises, might provide a clue.

Do you mean it doesn’t crank very robustly, that rrr rrr rrr sound with the key in start? Or do you mean it cranks ok, but takes a long time to catch and start running?