Recent Topics
F1 - 2018 Russian Grand Prix
by gofast182. 09/26/18 06:11 AM
Pets Puking in Middle of the Night :~/
by LoneRanger. 09/26/18 05:16 AM
Is there a new (2018) list of GM Dexron VI licensees?
by garageman402. 09/26/18 01:20 AM
Thoughts on new AMAZON branded oil...?
by PantherFan88. 09/25/18 10:47 PM
Clutch kit?
by andrewp1998. 09/25/18 10:34 PM
Galaxy S8+ weird app when clearing storage
by KrisZ. 09/25/18 10:18 PM
Brake bleeder - cfm ?
by hallstevenson. 09/25/18 09:43 PM
18' Corolla vs 18' Elantra
by wolf_06. 09/25/18 09:41 PM
Using Tc-w3 bad for my car?
by Floydian. 09/25/18 09:25 PM
I'm going to start using type F in my gm autos
by turtlevette. 09/25/18 09:17 PM
Cleaning deceased MIL condo and found $15K cash
by Mr Nice. 09/25/18 09:12 PM
Gluten
by StevieC. 09/25/18 07:55 PM
Amazon Prime delivering inside your house
by StevieC. 09/25/18 07:49 PM
2018 MB C300 M1 0W-40 3,475 Miles
by 2015_PSD. 09/25/18 06:44 PM
02-05 Silverado frame rot
by Oildudeny. 09/25/18 06:38 PM
Aftermarket Back Up Camera
by lancerplayer. 09/25/18 06:20 PM
Service champ filter CUT OPEN
by 53' Stude. 09/25/18 05:05 PM
Pressure washer pump life just 23 hours?
by HawkeyeScott. 09/25/18 05:01 PM
Newest Members
Everzooom, donnyw, Dfeeds, JJ_RA, Captjayd
66077 Registered Users
Who's Online Now
74 registered members (AndyB, Astro14, 2015_PSD, 2K2AcuraTL, advocate, ABomb369, 5 invisible), 928 guests, and 46 spiders.
Key: Admin, Global Mod, Mod
Forum Statistics
Forums67
Topics291,028
Posts4,854,768
Members66,077
Most Online3,590
Jan 24th, 2017
Donate to BITOG
Previous Thread
Next Thread
Print Thread
Hop To
5.3 LS 300k Busted Piston #4473141
07/28/17 03:18 PM
07/28/17 03:18 PM
Joined: Dec 2006
Posts: 623
Lynchburg, Va
JasonC Online content OP
JasonC  Online Content OP
Joined: Dec 2006
Posts: 623
Lynchburg, Va
Here is a pic from a 2003 Silverado 5.3 with 300k. It broke a valve which caused it to punch a hole in the Piston and trashed the combustion chamber. This truck was bought in 2006 with only 40k and it has always used M1 5w30. I'm impressed with how clean the tops of the pistons are. The rest if the bottom end was just as clean. We believe that a clogged cat is what caused the pressure buildup and broke the valve.


Last edited by JasonC; 07/28/17 03:20 PM.

2012 Buick Verano 2.4
2006 Ford Mustang GT Convertible
Re: 5.3 LS 300k Busted Piston [Re: JasonC] #4473144
07/28/17 03:25 PM
07/28/17 03:25 PM
Joined: Nov 2008
Posts: 3,157
Oshawa, Ontario Canada
JC1 Offline
JC1  Offline
Joined: Nov 2008
Posts: 3,157
Oshawa, Ontario Canada
Your pic is on photobucket. They are blocking links to other websites.


2015 Grand Caravan SXT Plus 5w-20 PPPP/Fram Ultra Filter
1997 Honda Civic CX 5w-30 Shell Conventional/Fram Ultra Filter
Re: 5.3 LS 300k Busted Piston [Re: JasonC] #4473145
07/28/17 03:26 PM
07/28/17 03:26 PM
Joined: Jan 2011
Posts: 2,944
PV Az
AZjeff Offline
AZjeff  Offline
Joined: Jan 2011
Posts: 2,944
PV Az
never mind

Last edited by AZjeff; 07/28/17 03:27 PM.

86 Samurai 1.3 leftovers
14 RAV4 2.5 5W-20 PP
16 Silverado 1500 4.3, DI, AFM 5W-30 PP

The most important thing to do in your life is to not interfere with someone else's life. - Frank Zappa

Re: 5.3 LS 300k Busted Piston [Re: JasonC] #4473150
07/28/17 03:30 PM
07/28/17 03:30 PM
Joined: Dec 2016
Posts: 6,270
Waco, TX
Linctex Offline
Linctex  Offline
Joined: Dec 2016
Posts: 6,270
Waco, TX
Originally Posted By: JasonC
We believe that a clogged cat is what caused the pressure buildup and broke the valve.


????

I kind of doubt that. I've floated many exhaust valves due to excessively high back-pressure on turbocharged race engines, and never had a failure like THAT! ("Float" is really only about .010"-.020" off the seat, any way)

clogged converter = engine has no power or quits, not broken valves.

This was a metallurgical flaw.


"The evidence demands a verdict".
(Re:VOA)"it's nearly impossible to actually know the particular additives that are in there at what concentrations."
Re: 5.3 LS 300k Busted Piston [Re: JasonC] #4473172
07/28/17 04:09 PM
07/28/17 04:09 PM
Joined: Aug 2011
Posts: 9,560
Boston, MA
HerrStig Offline
HerrStig  Offline
Joined: Aug 2011
Posts: 9,560
Boston, MA
So check the cat. I doubt it's the cause, though, more like a bad valve.

Re: 5.3 LS 300k Busted Piston [Re: JasonC] #4473207
07/28/17 05:01 PM
07/28/17 05:01 PM
Joined: Jun 2003
Posts: 17,379
Deplorable in apple valley, ca
Chris142 Online content
Chris142  Online Content
Joined: Jun 2003
Posts: 17,379
Deplorable in apple valley, ca
Valve guides got loose and let the valve bend when it seated and it eventully broke off.


02 Wrangler durablend 10w40
87 F250 traveler 15w40
04 Tahoe super-s 10w30
Z400 castrol T 10w40
Can am maveric edge 5w40
57 case tractor 15w40
Re: 5.3 LS 300k Busted Piston [Re: Chris142] #4473274
07/28/17 06:41 PM
07/28/17 06:41 PM
Joined: Dec 2006
Posts: 623
Lynchburg, Va
JasonC Online content OP
JasonC  Online Content OP
Joined: Dec 2006
Posts: 623
Lynchburg, Va
Originally Posted By: Chris142
Valve guides got loose and let the valve bend when it seated and it eventully broke off.


Incorrect. There was nothing wrong with the guide or the valve spring. The converter was clogged.


2012 Buick Verano 2.4
2006 Ford Mustang GT Convertible
Re: 5.3 LS 300k Busted Piston [Re: Linctex] #4473276
07/28/17 06:42 PM
07/28/17 06:42 PM
Joined: Dec 2006
Posts: 623
Lynchburg, Va
JasonC Online content OP
JasonC  Online Content OP
Joined: Dec 2006
Posts: 623
Lynchburg, Va
Originally Posted By: Linctex
Originally Posted By: JasonC
We believe that a clogged cat is what caused the pressure buildup and broke the valve.


????

I kind of doubt that. I've floated many exhaust valves due to excessively high back-pressure on turbocharged race engines, and never had a failure like THAT! ("Float" is really only about .010"-.020" off the seat, any way)

clogged converter = engine has no power or quits, not broken valves.

This was a metallurgical flaw.



The converter was clogged


2012 Buick Verano 2.4
2006 Ford Mustang GT Convertible
Re: 5.3 LS 300k Busted Piston [Re: JasonC] #4473277
07/28/17 06:43 PM
07/28/17 06:43 PM
Joined: Dec 2006
Posts: 623
Lynchburg, Va
JasonC Online content OP
JasonC  Online Content OP
Joined: Dec 2006
Posts: 623
Lynchburg, Va


2012 Buick Verano 2.4
2006 Ford Mustang GT Convertible
Re: 5.3 LS 300k Busted Piston [Re: JasonC] #4473389
07/28/17 08:52 PM
07/28/17 08:52 PM
Joined: Jun 2009
Posts: 3,699
Chicago, IL
tomcat27 Offline
tomcat27  Offline
Joined: Jun 2009
Posts: 3,699
Chicago, IL
crazy! what are you gonna do with it?


2019 Cherokee, 2015 Rogue, 2014 Sentra, 2001 Camry, 2005 Starcraft, 1998 Dodge B1500
1996 Sebring Jx, 1984 F150, 1970 Cougar, 2013 XT250, 2010 Vstar, 2014 CTX1300
Re: 5.3 LS 300k Busted Piston [Re: JasonC] #4473407
07/28/17 09:13 PM
07/28/17 09:13 PM
Joined: Nov 2008
Posts: 9,048
Phoenix
dishdude Offline
dishdude  Offline
Joined: Nov 2008
Posts: 9,048
Phoenix
Were you redlining it when that happened?


2018 Challenger SRT
Re: 5.3 LS 300k Busted Piston [Re: JasonC] #4473636
07/29/17 06:07 AM
07/29/17 06:07 AM
Joined: Oct 2008
Posts: 19,097
Sunny Florida
SteveSRT8 Offline
SteveSRT8  Offline
Joined: Oct 2008
Posts: 19,097
Sunny Florida
300k with stock parts the valve guides were definitely worn. We have raised and killed dozens of 5.3's and they rarely break. We have had many clogged cats at high miles and yet zero engine failures, even when racing them at far past factory redline.

Sorry, but I don't see a clogged exhaust breaking a valve like that...


"In a democracy, dissent is an act of faith."
J. William Fulbright
Best ET-12.79 @ 111 mph
4340 pounds, Street tires
Just like we go to Publix
Re: 5.3 LS 300k Busted Piston [Re: JasonC] #4473957
07/29/17 02:42 PM
07/29/17 02:42 PM
Joined: May 2012
Posts: 5,397
Fort Lauderdale, FL
DoubleWasp Offline
DoubleWasp  Offline
Joined: May 2012
Posts: 5,397
Fort Lauderdale, FL
I dealt with a clogged cat on my Navigator. It was clogged so bad that I had to disable overdrive and floor the truck to get to 55 mph. Even that never broke a valve.

I suppose anything is possible, but I have much much doubt that a clogged cat was your issue.

I'm betting it was one of the other top causes of valve fracture.


07 Lincoln Navigator M1 0w-40/FU
68 Charger R/T / Supercharged 440 VR1/DBL7349
07 Ram 3500 4x4 / Cummins 6.7 /DBL7349
17 Maserati GranTurismo Cabrio
Re: 5.3 LS 300k Busted Piston [Re: tomcat27] #4475437
07/31/17 10:39 AM
07/31/17 10:39 AM
Joined: Dec 2006
Posts: 623
Lynchburg, Va
JasonC Online content OP
JasonC  Online Content OP
Joined: Dec 2006
Posts: 623
Lynchburg, Va
Originally Posted By: tomcat27
crazy! what are you gonna do with it?
We put some JB Weld on the Piston and slapped it back together. Should be good for another 300k. J/K we have a crate motor going back in.


2012 Buick Verano 2.4
2006 Ford Mustang GT Convertible

BOB IS THE OIL GUY® Powered by UBB.threads™