Help! Terrible rattle

[MPRCTCL]

Just got stopped at the store and when I shut off the engine, it seemed to stop abruptly. I restarted ti and noticed a distinct rattle noise. Shut it off again, again an abrupt stop. Looking under the hood, there was a little smoke coming from the right front of the engine, low down. No obvious oil or source of smoke. Let it cool a few minutes and drove home less than a mile. Now the rattle is more constant. I can’t tell if it is internal or external but it seems to be slightly more on the right (Passenger) side. Ran it just long enough to check for DTCs (none), do a snapshot, and shoot a video. The video is too large to attach, so I will try to edit it down and attach later.

Here are some things that may have nothing to do with the problem.

2008 V
44,000 miles
Just got an oil change yesterday, Mobile 1 and it is still showing full now.
No leaks seen anywhere
30 psi oil pressure (Tech2)
Not running hot
Serpentine belts may be original

 

[MPRCTCL]

and the video...

 

[Bill S.]

Holy Smokes !!!!!!!! Sounds like something hitting the engine cover.

Bill

 

[mickeytee]

You may have to jack it up and get under it but that sounds like tha a/c compressor clutch locking up or the powersteering pump pulley loose and hitting. the hydralic belt tensioner could also be the culprit

 

[MPRCTCL]

You may have to jack it up and get under it but that sounds like tha a/c compressor clutch locking up or the powersteering pump pulley loose and hitting. the hydralic belt tensioner could also be the culprit

The noise is definitely coming from that side now that I listen again. Also, one of the belts just started to shred - I think it is that one. Where the engine stopped, I can't see any damage to the belt, but there are belt-chunks thrown around. Maybe it is an optical illusion, but the a/c compressor CORRECTION: the power steering pump pulley appears to be crooked? I hope I can get under it... seems problematic as my jack is too tall. I'll try driving up on boards to see if I can get above the jack.

Stay tuned...

 

[MPRCTCL]

Good-ish news. The bolt holding the p/s pump pulley wasn’t even finger tight. I wasn’t able to thread it out around the hoses, but I knew that the interface can be a failure point, so I wanted to see it. Mickeytee, what should I be looking for here? It doesn’t look spun to me, maybe just loose and I caught it before it got damaged??? Locktite on the bolt when I reassemble it?

 

[mickeytee]

Well you are going to have to pull the pulley off to be able to properly put the pulley bolt backnin. three bolts on the housing . it takes a special tool to hold the drive the pulley bolts into. the problem isvthe cause of tge bolt coming out. Usually the pump splines and the hub splines are worn which causes the pulley to chatter and then it comes loose. Every one ive seen wears the inner hub so that pulley is not tight on the shaft. I have all the parts and have rebuilt about 15 of these so far. When you get the pulley hub off let me know . call me and i will tell you what to look for.

 

[mickeytee]

Ok i just saw the photo of your hub and its going to have to be replaced.

 

[MPRCTCL]

Ok i just saw the photo of your hub and its going to have to be replaced.

I’m looking at the pulley and I don’t see an area that has / had a spline. Is part of the hub / pulley assembly still on my pump? You mentioned a special tool, but I can’t see where it would attach.

 

[mickeytee]

You are going to have to pull the aluminun hub off the car. It has three bolts holding it in. It has splines inside the center drive bushing that slide over the pump. the center drive shaft has flat sides on the rear to hold it and torque the pulley all together. Trying to tighten the bolt will just turn the pump. Plus the part of the drive shaft is obviouslly worn where the pulley bolts on. Sometimes the pulley hole is worn enough it has to be welded and reshaped on the lathe.if not centered,torqued and balanced it will never stay tight.

 

[mickeytee]

Here is a new pump with the new drive shaft slid over the splines on the pump. The internal splines on the factory shaft are very soft and wear. the end that the pulley goes on has to be almost a pressed fit. The flat sides on the shaft are how you hold it to put the proper torque on the pulley bolt. The shaft rides on two bearings that are inside the hub with a spacer between them.

 

[MPRCTCL]

The problem was the power steering / supercharger drive pulley had come loose from the spindle The V uses that pulley to drive the supercharger belt and there is a lot of tension on it, so Cadillac used a supported spindle assembly to carry that load instead of the power steering pump itself. I guess this is a common failure and when it came loose, it didn't take long to start grinding on the casting. You can see in the first picture that the pully assembly at the top of the pic is out of alignment. Once the belts were removed, it was very clear this was the problem. As seen in the later pictures, the pully and spindle shaft it mounts on were both damaged.

With the help of mickeytee (and impossible without his help) I got it fixed. He walked me through the diagnostic and disassembly, then he was able to remanufacture the otherwise-unavailable assembly for me. I don't mean he cobbled something together for me, I mean he really fully remanufactured it and I couldn't be happier.