260k LS3 - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

Crand · 01-26-2023, 08:15 AM

One day about a month ago, I went to start my car and heard some things happening which I'd never heard before but knew were absolutely not good, and I immediately turned the key back to off. I parked to the car and started purchasing parts. Just last night I finally got deep enough into the engine to find the cause of my concern. I've attached a photo of the culprit. Headed to a machine shop with the block and heads today to find out if they can be rebuilt, which I really hope they can because I've had a LS3 on order with summit since October and the estimated ship date isn't till June. If I can fix this before the new engine ships, I'll cancel that order.

The strangest thing about this problem is that I have never had an issue with the cooling system in the car. Never had a leak, there's never been any sort of grime in the system, when I took it apart the coolant was still crystal clear and the radiator's fins were like brand new. So without overheating I don't know how this happens but there it is. I think I was extremely lucky that this happened when I was trying to start the car instead of while it was under power because there's just a tiny nick on the piston but as far as I can tell absolutely no damage other than what you see here. After the machine shop gets into it, I'll know more but so far it looks like I might have narrowly gotten away with it.

1JEWLDSSRS · 01-26-2023, 10:49 AM

Dang man, I have never seen a valve seat come lose like that before! You may have gotten lucky on that one. Since these heads are aluminum and the seats are pressed in, I would have the machine shop check EVERY one of them, possibly replace them all as well so this doesn't happen again down the road. Also have them check the valve head and stem to make sure there is no damage to it so it will still seat properly in the new seats. You might want to do a complete valve job as well if you plan on keeping the car. Good luck sir.

gtstorey · 01-26-2023, 11:02 AM

I would probably spend the $2000 to get new heads.

Aqua Blue RS/SS · 01-26-2023, 03:15 PM

Quote:

Originally Posted by 1JEWLDSSRS

Dang man, I have never seen a valve seat come lose like that before! You may have gotten lucky on that one. Since these heads are aluminum and the seats are pressed in, I would have the machine shop check EVERY one of them, possibly replace them all as well so this doesn't happen again down the road. Also have them check the valve head and stem to make sure there is no damage to it so it will still seat properly in the new seats. You might want to do a complete valve job as well if you plan on keeping the car. Good luck sir.

Yep… With any good machine shop that is common place. You don’t set the machines up to do just on valve and put it back together. If that is a competent shop it’ll get a full rebuild and nothing else.

A new set of heads isn’t a bad Avenue either.

Crand · 01-30-2023, 10:06 PM

I'm having the good head rebuilt and replacing the one that dropped the seat. Doing this on a budget so can't do everything I'd like to do or the way I'd like to do it. Dropping a seat without taking the rest of the engine with it is something I consider lucky but this also happened in such a way I believe I asked for it. I drove the car about an hour across town, parked at a gas station for a fountain soda, and then started the car again while she was still hot and it was between there and my destination which was just 2 minutes away that I heard the valve hitting the piston. I've heard stories of this happening before, because engines that are designed like this only flow water through the heads and block while the engine is running, heat can soak into the heads after shutdown, and then if you start up the engine again really quick, you can drop a seat because of the different expansion rates of the metals. So what I'm going to start looking for now is an electronic water pump so I can keep water flowing through the engine and heads after I turn the engine off until it reaches my desired temperature. I think this will increase the life of aluminum heads. The car definitely didn't overheat before this, but the fact that the engine was hot from driving across town, and then I shut down and start it up right away, definitely had something to do with it because there's plenty of examples of this exact scenario happening. I just got lucky that it was idle when I heard the noise and I immediately killed the engine. Should have the engine and head back from the machine shop in a week or two, then I'll rebuild it and see how she goes!

acammer · 01-31-2023, 05:34 AM

Got lucky on that deal that it let go under the conditions that it did. Go pick up a lotto ticket!

01-26-2023, 08:15 AM	#1
Crand Drives: away the ladies :( Join Date: Aug 2012 Location: Phoenix, AZ Posts: 235	260k LS3 One day about a month ago, I went to start my car and heard some things happening which I'd never heard before but knew were absolutely not good, and I immediately turned the key back to off. I parked to the car and started purchasing parts. Just last night I finally got deep enough into the engine to find the cause of my concern. I've attached a photo of the culprit. Headed to a machine shop with the block and heads today to find out if they can be rebuilt, which I really hope they can because I've had a LS3 on order with summit since October and the estimated ship date isn't till June. If I can fix this before the new engine ships, I'll cancel that order. The strangest thing about this problem is that I have never had an issue with the cooling system in the car. Never had a leak, there's never been any sort of grime in the system, when I took it apart the coolant was still crystal clear and the radiator's fins were like brand new. So without overheating I don't know how this happens but there it is. I think I was extremely lucky that this happened when I was trying to start the car instead of while it was under power because there's just a tiny nick on the piston but as far as I can tell absolutely no damage other than what you see here. After the machine shop gets into it, I'll know more but so far it looks like I might have narrowly gotten away with it. Attached Images

01-26-2023, 10:49 AM	#2
1JEWLDSSRS Drives: 2011 SS-RS Join Date: May 2011 Location: FLORIDA Posts: 11,485	Dang man, I have never seen a valve seat come lose like that before! You may have gotten lucky on that one. Since these heads are aluminum and the seats are pressed in, I would have the machine shop check EVERY one of them, possibly replace them all as well so this doesn't happen again down the road. Also have them check the valve head and stem to make sure there is no damage to it so it will still seat properly in the new seats. You might want to do a complete valve job as well if you plan on keeping the car. Good luck sir. __________________ TSP STAGE 3 CAM,231/246 @112 LSA 614/641 LIFT, CIRCLE D 5C-4200-4500 CONVERTER,LOD INTAKE.CORSA EXHAUST. DSS 1 PC DS. PEGASUS SOLID CRADLE MOUNTS. 486RWHP/475RWTQ.LOTS MORE.

01-31-2023, 05:34 AM	#6
acammer GPI Sales Consultant Drives: 2011 Camaro 2SS SGM Join Date: Jul 2016 Location: Weedsport, NY Posts: 2,820 View My Garage	Got lucky on that deal that it let go under the conditions that it did. Go pick up a lotto ticket! __________________ GPI Max Package 2.0: Brodix BR7 heads/GPI porting, MAX3 cam, ST2116LSR, BSR Max Lift rockers, LS7 LSXR with 103mm TB, Vararam OTR, Mcleod RXT, G-Force/Strange 9" IRS setup with 4.63 gear. 551whp, 11.1@124mph. *Got a question about a GPI product? Feel free to shoot me a message!*

01-26-2023, 11:02 AM	#3
gtstorey Drives: 2010 Camaro SS2,L99, LSA SC Join Date: Aug 2017 Location: Huntsville, AL Posts: 2,178	I would probably spend the $2000 to get new heads.

01-30-2023, 10:06 PM	#5
Crand Drives: away the ladies :( Join Date: Aug 2012 Location: Phoenix, AZ Posts: 235	I'm having the good head rebuilt and replacing the one that dropped the seat. Doing this on a budget so can't do everything I'd like to do or the way I'd like to do it. Dropping a seat without taking the rest of the engine with it is something I consider lucky but this also happened in such a way I believe I asked for it. I drove the car about an hour across town, parked at a gas station for a fountain soda, and then started the car again while she was still hot and it was between there and my destination which was just 2 minutes away that I heard the valve hitting the piston. I've heard stories of this happening before, because engines that are designed like this only flow water through the heads and block while the engine is running, heat can soak into the heads after shutdown, and then if you start up the engine again really quick, you can drop a seat because of the different expansion rates of the metals. So what I'm going to start looking for now is an electronic water pump so I can keep water flowing through the engine and heads after I turn the engine off until it reaches my desired temperature. I think this will increase the life of aluminum heads. The car definitely didn't overheat before this, but the fact that the engine was hot from driving across town, and then I shut down and start it up right away, definitely had something to do with it because there's plenty of examples of this exact scenario happening. I just got lucky that it was idle when I heard the noise and I immediately killed the engine. Should have the engine and head back from the machine shop in a week or two, then I'll rebuild it and see how she goes!