Failed #1 Crank
 

My rebuild mechanic had an issue with the crankshaft last year that locked up the 1989 911 3.2L. He had the crank rebuilt and repaired. Almost a year to the date, he lost the #1 crank when he started the car and heard knocking, this after 100+ miles on new engine.

I’m not an expert by any means, but is it possible to salvage any of new cams, barrings, valves and other bench work completed or are we talking about a complete rebuild?

Specifically what do you mean by "lost #1 crank"?

He said the #1 Rod failed as he heard knocking….

It’s possible. You have to inspect and measure every item that you plan to reuse. You also have to investigate to make sure the mechanic didn’t cause the problem or overlook the reason why the engine locked up or the crank failed.

Given this is the mechanics second blown rebuild in two years. I’m not sure if it’s worth him reworking the crank to only have it fail again and essentially be back to square one.

Still not clear.

Did the #1 rod bearing fail, causing rod knock? That usually doesn't cause the engine to "lock up." That's due to oil starvation.

Or did the #1 rod break, whacking around inside the case? That will lock up the engine, but also bash the hell out of the case, piston, cylinder, etc. Very different things.

I’m not sure if the engine locked up. He just told me it was knocking when he started it up and he believed the number one rod failed.

Simple answer is to do a complete rebuild. That doesn't mean "replace" everything. It never does.
What you need to do is disassemble the engine and measure everything. If the rebuild was correct, the new parts are still new. If the assemblies were rebuilt properly then those assembly should measure in spec. A low mileage explosion is about isolating the issue that caused the damage and assessing the extent of the damage.
Things like valve and valve guilds should measure in spec. The oil pump, intermediate shaft , gears, chain and sprockets will still be in spec. The big ticket will be crank and Ps & Cs. My guess in the case of a failed #1 rods bearing is misfit or crank contamination. Every crank should have plugs pulled and cleaned after being repaired.
Every crank we get back from the crank shop has a tag that states, "crank cleanliness is the mechanic's responsibly."

The mechanic, if you want to call him that, claims a virgin crank would fix the issue. Two other shops I talked w/ basically quoted me 30-50k to resolve.

Failure analysis first. Then decide what to do. Take Henry's advice and plan to disassemble and measure everything.

Being optimistic that the engine was rebuilt with the proper/mandatory new parts, numbers like 30-50K are way out of wack.
Could you find that the requisite new parts weren't used, of course the price will be higher. Sometimes prices reflect the fact that a shop isn't really accustom to air-cooled rebuilds.

What Bloomington are you in?

Formerly Indiana, now near Chicago

Always sorry to hear these stories, guy just wants to drive his car. Hopefully some Chicago Pelican will throw you a lifeline and help you tear down and see what’s what. A reputable builder would fix the problem or at least give you refund after 100 miles.

Thank you. The mechanic, who was reputable at one time, continues to want to remedy the issue. The issue is I have no confidence in him as this was the second time he blew out the rebuild. The first time was a year to the date and it took a full year to manage. He’s had the vehicle for 2 years now and had the audacity to ask for more money to keep his shop a float.

Maybe the builder could source the necessary parts for the rebuild and you can have someone else assemble the parts. Not an ideal situation but maybe worth the conversation.

Sorry to hear this. Sounds like this guy blew it, twice (quite literally). This is a tough situation, but as you seem to suggest, I'd be asking whether you really want to let him do it a third time. Especially if he is asking for more money.

I gave him a months time line. He said there wasn’t a complete break where the rod was boaring through the engine causing excessive damage. He is going to put a replacement crank in the vehicle and I didn’t give him a dime.

DANGER. If he needs money to keep his shop afloat, how is he going to get a new/replacement crank on his dime? You could end up with your car stuck in his shop under bankruptcy for many more months. If I were to continue to do business with him, I would insist that he acquire the crank, bearings, and the usual gaskets, etc., BEFORE delivering the car to him, then take the car back to your house while he reworks the engine, then deliver it back to him when it is ready to install.

Other option: remove the engine yourself, disassemble it and inspect for damage, then he acquires replacement parts, then you give him the engine and he rebuilds it. Only when complete do you take the car back to have it installed. Keep everything on a tight leash.

He is floating the cash for the new crank, so he says. The car was set to be transported from Indiana to Illinois today but he called me yesterday to inform me the crank failed. I never had the car back in my possession. The vehicle failed after 150+ miles on it during the “break/in” phase. He also claims he could get a used crank and have the engine repaired, given there was very little metal shards present as the rod didn’t break and damage the case, ect. In 30 days.

I cant get the car into another shop for 30 days, so I’m going to see what he could do. Mind you I expect much of the same, blaming everyone else, oil companies, crank machinist's, ect. Although, if he makes this happen, I’ll only be out the balance vs. starting over in a new shop. My confidence level is low but I suppose I don’t have much of a choice.