LS7 valve guide issue? I'm confused about actual cases

[Coolpa]

I have 2013 427 vert w/4500 miles. I have been doing a lot of reading on the subject and I get conflicting info!! 7 out of 1000, 50 out of 1000. "Don't worry it's really very small %"" only between the 2006 to 2011? Darn wish I could get a definitive answer. I am concerned but still don't know weather I should wait 10k then have it checked or what. Frustrating!! I don't know what to think.
Im thinking about calling American Heritage, or Texas Speed, but they want the business so of course
they will say, "you need to bring your heads to us now!" Help!!

 

[Hib Halverson]

A '13 with 4500 miles on the engine is unlikely to have valve guide trouble. If you are worried enough that you want it checked, you need to wait until the engine has more miles on it or you start to notice any symptoms such as high oil consumption or excessive valve noise.

That said, if you are looking for a service facility which has experience with LS7 cylinder head repair the best choice is West Coast Cylinder Heads. They have been doing LS7 valve guide work for years. They are Katech's vendor of choice for LS7 porting work.

Texas Speed would be my second choice.

American Heritage is overrated in my opinion.

 

[Coolpa]

A '13 with 4500 miles on the engine is unlikely to have valve guide trouble. If you are worried enough that you want it checked, you need to wait until the engine has more miles on it or you start to notice any symptoms such as high oil consumption or excessive valve noise.

That said, if you are looking for a service facility which has experience with LS7 cylinder head repair the best choice is West Coast Cylinder Heads. They have been doing LS7 valve guide work for years. They are Katech's vendor of choice for LS7 porting work.

Texas Speed would be my second choice.

American Heritage is overrated in my opinion.

yes thank you so much!! Yes at 10k checking it out

 

[Hib Halverson]

If you decide to have your stem-to-guide clearances checked at 10,000 miles know that, regardless of what you read on various forums, it is very difficult to perform the so-called "wiggle test" in a manner that gets accurate data. If guide wear is a "borderline problem" a "wiggle test" may or may not confirm wear over GM's limit. American Heritage claims on the CF to be able to do it, but when you look at their measuring set-up, they obviously cannot. Accurate wiggle testing is extremely difficult. There is an article about it here

A "wiggle test" can easily determine a problem if guide wear is severe. It also can determine if there is no problem at all. What it can't do is give you a concrete determination if actual guide wear is present, and perhaps outside GM service limits, but not severe.

If you have a guide wear problem which is borderline, the heads will need to be removed and disassembled to determine if the guides are truly wearing outside of specifications.

Again, with a '13 which sees normal street driving, I tend to think you are not in danger.

For more information on LS7s and valve guide wear, see this article here on the CAC.

 

[Coolpa]

If you decide to have your stem-to-guide clearances checked at 10,000 miles know that, regardless of what you read on various forums, it is very difficult to perform the so-called "wiggle test" in a manner that gets accurate data. If guide wear is a "borderline problem" a "wiggle test" may or may not confirm wear over GM's limit. American Heritage claims on the CF to be able to do it, but when you look at their measuring set-up, they obviously cannot. Accurate wiggle testing is extremely difficult. There is an article about it here

A "wiggle test" can easily determine a problem if guide wear is severe. It also can determine if there is no problem at all. What it can't do is give you a concrete determination if actual guide wear is present, and perhaps outside GM service limits, but not severe.

If you have a guide wear problem which is borderline, the heads will need to be removed and disassembled to determine if the guides are truly wearing outside of specifications.

Again, with a '13 which sees normal street driving, I tend to think you are not in danger.

For more information on LS7s and valve guide wear, see this article here on the CAC.

Hi Hib!! Thanks for your comment!! Yes I use it on the street but I don't baby it and it sees high non
Sustained, 1st and 2nd spurts. So what your saying is, is conflicting with, "it's not a question if, it's when". A friend of mine has 41k on his 427 vert, no problems, but I know he babies it. Could you
explain more why you think I'm not in danger. Mileage? Thank you!