Surviving 67

About a month ago I started this thread: http://forums.corvetteforum.com/c6-z...aded-tick.html If you read it you will be up speed on what I thought was the dreaded tick.

The dealership that has my car called me last week to tell me that they had pulled my rocker arms and they were in good condition. Next thing they did was pull the spark plug, fill the cylinders with air, pull the valve springs, attach a dial indicator to the head while the head is still on the car and measure the movement of the valve in the guide.

The dealership told me that the spec was .002 and mine were all at or above .008. They sent this information to the engineer at GM and they are sending a new set of heads for my car.

Several interesting things come to mind in response to the LS7 guide wear sticky. First the build date on my engine is May 3, 2011. The second thing is that the dealership was able to measure the valve guide/valve play without removing the heads and there was a spec out there for this. Lastly my car has less than 4500 miles on it and most of those miles are freeway miles which leads me to believe that it must have left the factory that way.

My car hasn't used any oil and it doesn't smoke at all, other than the tapping noise that many people seem to think is normal I would have never know there was an issue.

I have also been talking to another member on this board that has a replacement engine in his car. His was assembled the day before mine on the same line as mine. He has about the same miles as I have on mine but a fair share of his miles are track miles and he said his sounds normal and doesn't use any oil, go figure.

The reason I posted this is so that members know that apparently there is an accepted way to measure the guide wear without removing the heads and maybe it will help others who are on the fence about whether the noise they are hearing is normal or not.

Bill

Go X-15 Go

Thanks for posting this.

Turbosixx

I think if more warrantied cars bring them in for valve train noise, GM would get the picture.
Thanks for posting this as well.

kenw

Thank you this is good information.

erick_e

This needs to be merged into the "official" thread.

Because GM's statement that the problem has been "contained as of Feb '11 with 100% inspection of all heads" cannot be correct if your guides are worn.

RedZ4me

First I'll say, it's great you are trying to help others,

but 2nd, .......I need to say this, I have little confidence in most dealers and their techs, granted, some are good and
3rd - .002 to .008 is six thousands out! that so, so small of a tolerance, any tighter the valve stem would seize in the guide, as heat makes metals expand..........hence the reason of valve guide seals to control oil..........some tolerance just needs to be there.

I'm not doubting your clearance issues but am doubting the dealers numbers. I say this as I know many at dealers and worked at one myself, got to know many of the techs, fact is most today don't repair, they just replace parts, especially since warranty is paying.

My guess? dealer doesn't really know so just going to throw on new heads.

** I did re-listen to you video, and the sounds around 2:20-2:35 bother me **

OH THREE Z

Thank you for posting this. It confirms my suspicion that this problem has not been remedied in post 01/2011 builds.

I guess that I don't see any real benefit in swapping to a new set of heads when there is the likelihood that they are as flawed as the set coming off.

My car is going in next week for a couple unrelated issues. I will mention this to my guy and report back. Btw, mine is a 12 with 5800 miles and just recently started to tic at 1600-1900 rpm.

This sucks

'06 Quicksilver Z06

Bill, after speaking with you, I am glad that you went ahead and thought it through and decided to go ahead and post this information up for the benefit of the forum.

So has GM fixed your car yet?

gatti-man

Just keep after it. Get your car checked and get it in writing that way if you ever have trouble you can take this info against GM. It's what I am doing.

Gary '09 C6

thanks

Surviving 67

[QUOTE=RedZ4me;1582103652]First I'll say, it's great you are trying to help others,

but 2nd, .......I need to say this, I have little confidence in most dealers and their techs, granted, some are good and
3rd - .002 to .008 is six thousands out! that so, so small of a tolerance, any tighter the valve stem would seize in the guide, as heat makes metals expand..........hence the reason of valve guide seals to control oil..........some tolerance just needs to be there.

I'm not doubting your clearance issues but am doubting the dealers numbers. I say this as I know many at dealers and worked at one myself, got to know many of the techs, fact is most today don't repair, they just replace parts, especially since warranty is paying.

My guess? dealer doesn't really know so just going to throw on new heads.

QUOTE]

I understand what you're saying but to this I will say that the dealership had to talk to the GM engineer before they would disassemble my engine. Then when they discovered the tolerances they had to call the GM engineer again to find out what the next step was. That was when the GM engineer advised them to replace the heads. If what you're saying is true then does that mean GM will just give anyone a new set of heads? I think we know the answer to that question.

Ricky, not yet they are still waiting on the new heads to arrive from GM. Both the GM rep and the dealership are in constant contact with me about what is going on, the rep calls me every couple of days to advise me what is going on.

RedZ4me

^^^

Do they give anyone new heads? , no........but will to many that have warranty........they make alot of $$ on warranty work.......trust me on this one. good luck and keep us posted

FrankTank

This makes me think the guides were out of spec when the car was built . Also , if I were you I would have the guides on the new heads measured before even putting them on the car ...

'06 Quicksilver Z06

The fact that this car is a May 2011 build date, when this matter was supposed to be contained in what was it????, February of 2011???, would leave me wondering too.

It tells me that it goes beyond February of 2011, and I don't think there is a rational thinking person in here who, at this point, believes that it didn't start until 2009.

But if they are saying that .0020 is the spec and his were all at, or above .0080, then that is a long way out of spec.

And like you, I don't believe that they "wore" out of spec in that few of miles. This implies that the heads were built with bad guides in them from the beginning, and thus there were still some bad guides out there when this motor was built......unless they put a set of "old" pre February 2011 built, non examined, heads onto his engine which was completed in May 2011.

If that's the case, then you wonder how many other sets of bad heads have gone onto engines built after February 2011.

But whatever is the case, a set of heads likely with bad guides, as he likely did not wear his guides out in 4500 miles, ended up on his motor which was built in May of 2011.


I guess Bill's got past the 100% inspection of all heads and "broke containment".

Either that or Stevie Wonder was doing the inspections.

Dirty Howie

Bill

Glad you finally posted up your important information. As you know my motor is also a May 2011


DH

Surviving 67

Howie, if you don't mind what are the 2, 3, 4 & 5 numbers on the sticker that is on your heads? I'm curious how close the assembly date is to mine and the other one I know about.

Dirty Howie

I don't mind but am too lazy to get out of bed and go in the garage.

I think I posted the whole number not too long ago when asking what the build date is. I will look for you .......


EDIT: I found my post ............ 10H61 321291102


DH

Surviving 67

Yours was built on the same line as mine, line #2 and 6 days after mine. I now know of 3 that were assembled within a week of each other. If yours and the other check out as fine then we truly know it is random.

MarkRx

who built the motor?

MTIRC6Z

This is a VERY good suggestion...personally I'd not only measure the guides before they went on the engine (the way WCCH does) but then do it again the way GM says to do it when the heads are ON the engine. This would be a great way to verify if the on engine measurement technique is reasonably accurate.

Of course measuring the guides on your old heads AFTER they came off the engine would be another way to verify the GM on engine technique, but I have no doubt NONE of this will be done because nobody really cares enough

Regardless billyjo, thanks for taking the time to share your experience with us.

Cheers, Paul.