Dropped valves ?

[2012 ZL1]

Some of the older, but not much older like 2007, pre-2010 LS and vortec motors (including 6.2's) are starting to drop valves and blow bearings. I'm wondering was the design changed for the L99 and LS3.. Has anyone heard of a 2010 SS dropping any valves yet ?

[toesuf94]

This sounds promising...My 6.2 in my Cadillac sounds like a diesel until it is warm...wonder if it is just a precursor to what you are talking about.

[2010 Bumblebee]

I saw 2 last week a 6.2 Cadillac escalade with a dropped valve, and a saab with a vortec 5.3 rapping.

[CC Performance]

It happens.... a lot more than people would think

[HDDAN]

Originally Posted by toesuf94

This sounds promising...My 6.2 in my Cadillac sounds like a diesel until it is warm...wonder if it is just a precursor to what you are talking about.

For what it's worth, I have had two LS1's, a 1998 Z-28 and a 2002 SS and they both sounded like cement mixers until they warmed up. It was the piston skirt design that caused this. They had piston "slap" when cold. I put 30,000 miles on the Z-28 and 65,000 on the SS with no problems. This was just a design characteristic. Don't worry, turn up the stereo until it warms up.

[toesuf94]

Originally Posted by HDDAN

For what it's worth, I have had two LS1's, a 1998 Z-28 and a 2002 SS and they both sounded like cement mixers until they warmed up. It was the piston skirt design that caused this. They had piston "slap" when cold. I put 30,000 miles on the Z-28 and 65,000 on the SS with no problems. This was just a design characteristic. Don't worry, turn up the stereo until it warms up.

That has been my remedy now for two years...just worries me that as soon as this thing is out of warranty...bang...bad news.

But, NO GM has ever made me walk home. NOT one time.

[CC Performance]

Originally Posted by HDDAN

For what it's worth, I have had two LS1's, a 1998 Z-28 and a 2002 SS and they both sounded like cement mixers until they warmed up. It was the piston skirt design that caused this. They had piston "slap" when cold. I put 30,000 miles on the Z-28 and 65,000 on the SS with no problems. This was just a design characteristic. Don't worry, turn up the stereo until it warms up.

You know the interesting thing about piston slap is that if you owned a Vette and complained hard enough they swapped them out.. the fbody guys didn't get that same treatment as far as I know. There is a whole website dedicated to it LOL... it wasn't the design as much as the acceptable tolerance .. maybe that is design.. if they had stricter standards then it would not have happened I guess...

[DLB]

i have a tahoe with the 5.3 and 140k+ miles..... theres is sometimes a noise that comes out but it would have to be really cold or not started in a long time.... goes away once engine is up to temp. being pulling heavy loads with the SUV every summer 5,000lbs+ and they only thing that has broke was a steering pump. a little noise for a chevy engine is always a good sign in my book.

[Fightinfire921]

Originally Posted by DLB

i have a tahoe with the 5.3 and 140k+ miles..... theres is sometimes a noise that comes out but it would have to be really cold or not started in a long time.... goes away once engine is up to temp. being pulling heavy loads with the SUV every summer 5,000lbs+ and they only thing that has broke was a steering pump. a little noise for a chevy engine is always a good sign in my book.

To me noises are signs of bad things to come.

[OUR72GTO]

me too...

Put 252000 KM on my 2000 Silverado 5.3 towing and it had that slap from day one. 2nd owner is very happy and expects 400,000 KM before the valve covers come off.

Brother's 2002 Firehawk has it too with NO PROBLEMS.

[Cam 427]

I have a 2001 GMC 2500 with 6.0 with about 140k. It has some lifter noise when cold but goes away when warmed up, other than that, it runs great.

[2012 ZL1]

Originally Posted by HDDAN

For what it's worth, I have had two LS1's, a 1998 Z-28 and a 2002 SS and they both sounded like cement mixers until they warmed up. It was the piston skirt design that caused this. They had piston "slap" when cold. I put 30,000 miles on the Z-28 and 65,000 on the SS with no problems. This was just a design characteristic. Don't worry, turn up the stereo until it warms up.

Yes they are noisy engines which has nothing to do with actual vavles dropping or bearing spinning. I'm talking about actual occurrences of dropped valves going into the motor and ruining the head and one cylinder. There seems to be a number of, pre 2010 camaro, LS and Vortec doing this lately. Then there are the blown bearings.

Originally Posted by DLB

i have a tahoe with the 5.3 and 140k+ miles..... theres is sometimes a noise that comes out but it would have to be really cold or not started in a long time.... goes away once engine is up to temp. being pulling heavy loads with the SUV every summer 5,000lbs+ and they only thing that has broke was a steering pump. a little noise for a chevy engine is always a good sign in my book.

Same thing, The motors are noisy that's fine.. Piston slap is a know issue, but I'm talking about valve breaking and dropping into the cylinder.. It's been happening on, pre 2010 camaro, 6.2 liter motors and other LS and Vortec motors.. If this were to happen to you wouldn't be guessing what it is , you'd know something is really wrong.

Originally Posted by 2010 Bumblebee

I saw 2 last week a 6.2 Cadillac escalade with a dropped valve, and a saab with a vortec 5.3 rapping.

Originally Posted by CC Performance

It happens.... a lot more than people would think

So here is what I'm curious about; did they change the design in 2010 or could some of us suffer the same fate one day ? This is one of the reasons why I don't alter my camaro in any way..

So, for those who may know, why are the valves dropping? is it a type, brand, design? is there a better type, brand , design to use if one were to have the intake off putting a supercharger on and willing to dig a little deeper into the motor to head the problem off before it happens ??

[HDDAN]

Valves are held in with split keepers and a tapered collet that holds the valve spring. I have not heard of anyone dropping valves. My 2002 SS made drag strip runs with no problem and my 2010 A6 L99 has m.ade a few passes and is fine. These engines have rev limiters to prevent damage. When I tried using. The tapshifter at new england dragway I ran right into it in first and second gears. I wou,ldn't worry about either V-8. Chevy has been making these thinghs sinvce 1955y.

[WHIPPLECHARGED]

The only way for the valve to drop into the cyclinder was if the spring broke allowing the keeper to come apart. That's why it is recomeded to install better valve springs when installing different cams.