Trashed bearings ~

[richard grimsley]

Well, the engine is pulled and two of the main bearings don’t look Good. This engine has no modifications at all made, merely the disassemble of the engine by a certified machanic. Does anyone recommend harassing GM to uphold to the warrenty or would this be a waste of my time and efforts being the engine issues were identified by not one of their GM employees?

[MX621]

I would certainly try, but being the engine was disassembled by someone other then a GM dealer you may have a uphill battle. Have the heads been inspected yet? Very unfortunate situation, I wish You the best!

[richard grimsley]

MX621- thank you sincerely.

The heads have been inspected. This was the purpose for me taking it in to the shop. Once the valves stem liners were identified to have excessive play, I had the heads removed to be repaired, not knowing or even feeling worrisome anything may be wrong with the short-block considering the short amount of mileage that was on it in addition to how cordial I had operated this vehicle. Then... to my astonishment I find the trail of crumbs in the “hand built- of specialty high performance” engine leading me to this.

I am rather discurished considering.

[kramard]

I would absolutely call Chevy and discuss. They probably wouldn’t pay for any of the labor to get to the point that you have but the damage is clear and couldn’t have been caused by the tear down. I probably wouldn’t do much more without getting Chevy involved if you want a chance of getting a new motor or some form of compensation though. Do you mind keeping us posted if you work with Chevy? As a prospective zl1 1le purchaser I’m curious t see how Chevy stands by their product in a case that isn’t so clear cut. I wish you the best! Hopefully it works out for the better!

[_Chigga]

Originally Posted by richard grimsley

Well, the engine is pulled and two of the main bearings don’t look Good. This engine has no modifications at all made, merely the disassemble of the engine by a certified machanic. Does anyone recommend harassing GM to uphold to the warrenty or would this be a waste of my time and efforts being the engine issues were identified by not one of their GM employees?

Wait wait wait, they are voiding your warranty simply just because, your engine was teared apart by a mechanic that doesn't work for GM? yeah I would try my best to let them uphold the warranty. Good luck man your gonna need it!

[j o n]

This has been discussed and happened to z/28 and z06 owners alike....

... Unless ths car/motor is intact and not tampered with is the only way GM will warranty it. Warranty is for sure voided now

[zcarczar]

Originally Posted by richard grimsley

Well, the engine is pulled and two of the main bearings don’t look Good. This engine has no modifications at all made, merely the disassemble of the engine by a certified machanic. Does anyone recommend harassing GM to uphold to the warrenty or would this be a waste of my time and efforts being the engine issues were identified by not one of their GM employees?

GM will flat turn it down, I'm in the dealer world and if we see a vehicle come in with engine problems we have to call the Technical assistance center first to get authorization to work on it. If we have seen evidence of someone being in the engine that wasn't a prior warranty repair the repair is immediately turned down unfortunately.

[JUSTIFIED]

Originally Posted by MX621

I’ve noticed the oil temps on the street only ever get up to 180deg or so. No matter how I drive it. Kinda concerns me a little because it never gets hot enough to boil off any moisture/condensation. My c5z oil temp lived at 210-220 oil temp all the time so it was never a problem.

Odd.... living in TX I often see 215+ in Summertime, but even in cooler weather (65ish) it reaches 200 (unless I granny it). No clue what might be causing it, but that doesn't seem right.

[MX621]

Originally Posted by JUSTIFIED

Odd.... living in TX I often see 215+ in Summertime, but even in cooler weather (65ish) it reaches 200 (unless I granny it). No clue what might be causing it, but that doesn't seem right.

I’ve only put 350 miles on it since buying it in October, and every time I’ve driven it, it’s been no warmer then 45 deg. So that may be part of my issue. My c5z oil got to 210-220deg no matter ambient temps. But that car has no oil cooler also

[j o n]

Decent chat about LS7 failures
https://gwatneyperformance.com/ls7-v...-need-to-know/

[MrRaZ28]

Thanks for that link Jon. Good read!

[MrRaZ28]

Originally Posted by MX621

I’ve only put 350 miles on it since buying it in October, and every time I’ve driven it, it’s been no warmer then 45 deg. So that may be part of my issue. My c5z oil got to 210-220deg no matter ambient temps. But that car has no oil cooler also

My oil only see's higher than 200 when I track the car. Otherwise, it's below 180 usually. Car rarely gets up towards 200, and then only in the deep summer.

[Russell James]

Originally Posted by MX621

I’ve only put 350 miles on it since buying it in October, and every time I’ve driven it, it’s been no warmer then 45 deg. So that may be part of my issue. My c5z oil got to 210-220deg no matter ambient temps. But that car has no oil cooler also

The Z28 will run cooler oil temps street driving than a C5Z because it has much more oil cooling and oil capacity.

I doubt your bearing issue has anything to due with oil temp. A global bearing wear/scoring issue is more likely oil starvation or oil contamination with debris.

I'd tear it down to the bare block. Inspect for anything shedding material. Also cut the filter apart and spread out the media. Either someone did a dry start on that with no oil in it, or something is creating debris that has trashed the bearings (more likely). Inspect con rods closely to make sure they have the correct side clearance and no excessive wear. If something titanium is wearing... Ti debris is uber destructive on bearings.

While rebuilding, I'd send the heads to a place like GPI or West Coast ... a place that specializes in perfecting LS7 heads with the better guides and polishing the valves. If going with an aftermarket cam, don't go crazy with the lift. Over .600" is going to accelerate guide wear. Use the best oil money can buy.

If the block, crank, rods, pistons.... are all good... no reason to buy a shortblock. Blueprint and freshen what you have.

[serviceguy]

I think having excessive valve guide wear at such low miles is also part of the story.
Starvation ?