DOUG @ ECS

We have been replacing so many LS7 heads lately here that we decided to put a video together of what the damage actually looks like for you guys to see first hand who do not do this stuff regularly.

It seems that almost every LS7 coming in here with 20k or more on the odometer (06-07 especially) has excessive wear and often the owner does not know it. The cars are getting dropped off for a supercharger or cam etc, but we have to start with repairing the heads first. To the point that we have a half dozen rotating LS7 heads in the works at all times now to shorten the wait for the customers.

It has come to the point where we can tell just by listening to the car, if you hold the RPM up to roughly 2k you can hear the play in the drive train. A handful of the owners just thought it's how the engine sounds since they bought the car second hand and are amazed how much quieter it is after repairing the cylinder heads. I do not have a video of that sorry, but here is a video of what the wear looks like itself.

Achilles97

Wow. Thanks for the video.

I do hear a bit of noise at 2k rpm. I think I need to just get my valves checked.

Property1

Do you have a video of what it sounds like at 2000 RPM if there is an issue? I have the stereotypical sewing machine noise at 2000 RPM in my car, but I have no idea if that is normal or if it's what you are referring to.

'06 Quicksilver Z06

Excellent information and a great help to the forum.

DOUG @ ECS

I do not have a video of that sorry, I also do not think I have the proper audio equipment to capture it properly, but I will try and take a video of the next car.

valet_devil

How did you "repair" this in the shop? Bronze guides and SS valves? What do you charge for your service?

DOUG @ ECS

We used to do all our own cylinder head repair work-porting etc and have the equipment, but now we core them out to WCCH. It's just more stream line for the customer that way.

Property1

Thanks for the response! Could you give your best guess as to what it sounds like? I get a sewing machine noise between 1500 and 2500 RPMs (after that, the engine noise drowns it out). I'm guessing this is not the noise you are referring to.

LanceFitzgiben

Holy cow that stem was moving on the head that was out of the car! Anyone who thinks this isn't an issue is blind to reality.

DOUG @ ECS

Thats about right yes. I would have your heads checked asap. To give a bad example, we had a customer who was already scheduled for this repair just waiting to get in drop a valve last week and grenaded the entire engine. Day late-dollar short...


edit, just to clarify- that IS the noise I'm referring too.

vray

Reality sucks!

ipmtim

So your saying bronze guides and SS exhaust valves?
Tim

DOUG @ ECS

Correct, ported or unported also depending on customer preference.

'06 Quicksilver Z06

Damn shame.

Too many people out there who think this can't happen to them.

It's a very real problem, and one which when you get down to it, is an easy one to fix so that you can drive the car without having to worry about it.

That poor guy was probably out of warranty too, because you say that he was scheduled to have the work done on his heads.

Now he needs a motor.

Of course there will be those who will say that it's all scare tactics. But for many it's yet another warning to be aggressive and proactive when it comes to addressing this issue, or end up regretting it.

Property1

Thanks. I'm going to get it checked out. I have always been under the impression (from this forum) that the sewing machine noise around 2000 RPM on these LS7 engines is completely normal, but I guess not.

Vette @ 71

How many out of tolerance cars have you seen without the sound in the drivetrain?

Jawnathin

Can you share details on how you determined the the 'sewing machine' noise at 2k RPM is a sign of a pending valve train failure and is not just how these LS motors sound?

FWIW, my car with stock heads had the noise. My car with the fixed WCCH2 heads makes the noise. LS7 Drew's car before and after his PRC265 heads made the noise. And there are a few others that still have that noise after the heads have been replaced. There are other LS-based cars with the same noise. I believe my brother's LS6 has a similar noise.

While I do suggest that folks who are worried about a drop should investigate their options, I'm not so sure that the 'tick' is a sign of an issue.

Turbooo2u

This really makes it tough as to what we should think/do about this problem. Another recent post shows many people with some significant mileage with no problems, with some speculating that this is only a 2% problem. So what is it, 2%, 20% or more??

'06 Quicksilver Z06

2% would represent a little less than 600 cars.

That's optimistic.

Svre46

I agree. ^^^ My car had a faint hint of sewing machine noise before having my heads done. Always thought it was normal. Now that they have stainless valves, dual springs and bronze guides it is still there. Car seems quieter overall...especially at idle.. but you can still hear that noise @1.5k-2k regardless. I have only have put on 100 miles since then. I’m doing a cam now so I will double check everything again while the covers are off. I am not worried one bit. Some people's hearing is better than others.