What would you do...?

I put in a 350 mile weekend on my 91 ts and its been over 700 miles since my major service. I get home last night, back the car into the garage and wait for the fans to stop before shutting down. As I am waiting I start to hear a slight 'hitching' noise that grows in duration, volume and frequency. In a mere 5 minutes its grown to a grinding-squealing right in front of me. I am freaking out and dive inside the car to turn the key off.

WTF has just happened? I get my nose into the engine bay and no signs. Both oil pressure and temp were fine... I leave the garage and go take some deep breaths, then to fchat to do a search entering my symptoms into the search field. I am thinking 3 possibilities - the 3 things that I didn't do during my engine out service!!!

1 - water pump (seemed to be just fine at the time)
2 - internal chain upgrade - Ferrari TSB
3 - tig weld the drive pulley flange to the pulley as they have been known to separate

So I go though the whole day today wondering about the best course of action moving forward. No Ferrari service around me for 1k miles. Throughout the day I am thinking about the alternator and its tensioner and the air con pump but I rule them out as the whole event came on too suddenly and it just didn't sound like a typical alt bearing failure (I've heard them before and there has always been indicators that they are slowly failing).

Getting on to the question of the above title - on my drive home from work I think "should I disconnect the alternator and ac belts and start it up again knowing that there is a possibility my water pump might now be seized or I have oil chain tensioner fragments floating around in my sump?" Possibly even a flange hanging off a pulley behind that timing belt cover!

I put the car on the lift this evening and took both belts off. Lowered it, climbed in and hit the key. The sound was gone and I was very relieved! I stopped the engine, raised the car back up and inspected the alternator - the bearings are completely shot. Spinning it squeals and it is very rough like gravel inside. What I am so surprised about is that a 348 alternator can have sudden total failure of the bearings and that it did not sound at all like an alternator failure (no warning light either).

Does the decision to start the car for diagnosis come down to ones comfortable level of risk?

What would you have done?

 

FBB - I believe you.

I tell you fellas, this was one of the worst feelings - don't want to go through it again... Next fall the lump is coming out again and I am going to inspect/replace any components behind that front cover. Also will replace the WP and am going to tig weld all my pulley flanges. I can't believe I didn't do them the first time around...

I did take the 5-8 cam cap off to inspect before I started it. I was concerned about the restart the next day because of what may have changed now that a full heat cycle had been completed.

The alternator is at the shop getting new bearings right now - I will post both ID and OD bearing dimensions as well as brand and part number on the 'parts interchange' thread.

 

I couldn't believe the meltdown happened as soon as I pulled into the garage - it was good bad luck.

New front bearing in the alternator was $57(parts and labour). Put it back in yesterday and all is perfect. I adjusted the belt tension to the lighter side - I'm going to experiment a bit to see how light a tension I can get without slippage or squeal. From what I can tell, less tension (while being easier on bearings) will create less front engine noise.