Ls6 deal (maybe)

[ztk123]

A few months back I posted about purchasing a 52k 5.3 that turned out to be a 4.8. After all the disappointment, I had just about made my mind up to go ahead with the 4.8 after installing a new camshaft. I have been looking for an LS6 intake (knowing I would lose torque, but like the look). When doing my nightly craigslist search I ran across an ad for an 04 LS6 CTS V engine. It had only been listed for a couple of hours. After making contact with the seller I learned he just replaced the engine due to an unfortunate incident. He told me while texting and driving he ran up on a curb at 35 mph and caused significant undercarriage damage to the car. The oil pan was not ruptured but after restarting the car heard a ticking sound. He took it to 2 local Chevrolet dealers and each of them recommended a rebuild or replacement. After receiving an insurance check for $5000 he had the engine replaced with a Corvette LS6. So I purchased the engine from intake to batwing oil pan including front accessories and even red Corvette covers for $750 (he didn't use the vette pan and covers). I listened to a video and there is a ticking sound. So far I have pulled the valve covers valvetrain looks okay, all the cylinder walls and crank look good from below. I guess I will tear it down soon and try to figure out where the noise is coming from. All in all I think it was a pretty good deal! Any advice is welcome.
Thanks, Mike

[BR3W CITY]

Post a video of the noise if you have it. I wonder if it just damaged the timing gear or stuck a lifter or something. You wouldn't be able to tell with the engine in the car, but it might still run even with that.

Got a boroscope?

[GMC-YA68]

could it be something as simple as the exhaust manifold got cracked?

[ztk123]

Trying to upload the video from my iPhone, but it says invalid file extension.
Any suggestions? Thanks, Mike

[BR3W CITY]

Its probably a 3gp file or something like that, which needs to be converted. If you can't do that, send me the file I can recompress it.

[ztk123]

Update, I took the heads off in hope of a bad lifter but all of them looked great. Didn't see any obvious internal problems either. BR3W CITY if you want to pm me an email address I will send you the video I have. If anybody else has any ideas before I take it to the machine shop let me know.
Thanks,
Mike

[Super73]

I am thinking it was something as simple as an exhaust leak and the dealers were taking advantage of the previous owner. I did sales at a dealer for <3 month and was amazed how bad a lot of the customer would get screwed on things. The ethics got to me and had to leave.

[BR3W CITY]

I'm starting to consider a flywheel bolt.

You Tube

[DirtyLarry]

Wonder if anybody pulled off the accessory belt(s) and listened to it run then? From the video it doesn’t sound internal catastrophic like a rod knock or anything deep. Like BR3W CITY says…sounds like something external rotational like a flywheel bolt, broken flywheel but even at that....I don’t see how a flywheel or flywheel bolt would get whacky in a hard curb shot accident as described but I could see how something in the accessory drive belt system could. I’ve heard some broken belt tensioners sound like pistons were swapping holes before. I've also seen starter drives bounce around between the starter motor and flywheel as the engine was running and make some crazy noises similar to this. The odd thing was the engine started just fine with no abnormal noises. That was on older 3.4L V6's but ya never know. I bet this is something simple whatever it is

[BR3W CITY]

^^The OP also added this in his email to me. The clutch and flywheel had been recently replaced by the previous owner. I'm gonna put the email here so everyone is up to speed.

The engine was revved from idle up to about 5000rpm. One other thing I didn't mention is that this came out of a t56 car. The guy told me that the clutch, flywheel and pressure plate was also replaced. The day I picked the motor up he said that he still had some sorta vibration in the drive line with the new motor and other parts replaced. Not sure if it could be related to the noise. I didn't find anything inside yet. Turned it over several times by hand, the timing chain does make a little noise but nothing obvious with it either

[DirtyLarry]

It would sure be interesting to see what that old clutch and pressure plate looked like when they came out. Too bad it isn’t as simple as the old days to just fire the engine up on the stand with a Gatorade bottle of gas and a pair of jumper cables. I bet there isn’t anything wrong with this engine but it is awfully scary to invest in a harness and all the install bits to toss it into an old truck only to find out there is something catastrophic wrong. Should have offered him $751 and took the whole car. It was just a ghetto cruiser Cadillac

[ztk123]

Many thanks to BR3W CITY for uploading the video! I appreciate all the feedback from you other guys as well. Internally everything looks fine. He had all the service info from the dealership that had regularly changed the oil with Mobil 1. I haven't found any shavings nor does the appear to be any rod problems. I rotated it by hand several times. Cylinders. valve train and inside of the engine look really clean. DirtyLarry, I already have a harness and a 4.8 in my blazer, plumbed and wired. I was just gonna try to find out the possible problems before pulling the other engine out. Wouldn't be out a lot of additional $ at this point just time and effort changing them out. I just couldn't pass up an LS6 for $750, figured at worst I could keep the intake and other stuff I wanted and still come out ahead. Hopefully I will be able to use the entire motor. Would turn out to be a great deal if I was able to get a 400hp all aluminum LS for that price.
Mike