[Spaceme1117]

So I just purchased a used 2017 Camaro SS.

Since the LT1 is a direct injected engine, how are people cleaning their intake valves?

Is this even much of a problem on these engines?

The car I purchased has 37000 miles on it and I know that some DI cars with that mileage have intake valves that are just horribly caked with carbon buildup.

Forgive my ignorance on this.

[m6-lt1]

The best way to clean them is to pop the intake manifold off and manually clean the 8 intake valves with the specific cleaner and tools they make for it. On these vehicles the intake manifold can be taken off and put back on in an hour by people with competent mechanical skills. You’ll be able to clean 7 of the 8 valves right away after popping off the intake and determining which valve looks open. To clean the open valve you will have to attach a long bar to the crank pulley and turn it (IN THE CORRECT DIRECTION!!!) in order to close the final valve and clean that one too. Once finished you pop the manifold back on and you’re done.

Now having said all that, these engines don’t seem to suffer from super caked up intake valves like their German counter parts do. I’ve seen examples of people going 100k + miles and the valves are only mildly caked up. In fact the examples I’ve seen posted on here both at low miles and high miles look nearly identical. I truly don’t believe this is an issue on the GM LT engines. And if they are, this is one of the more simple engines to clean them on.

[Spaceme1117]

Originally Posted by m6-lt1

The best way to clean them is to pop the intake manifold off and manually clean the 8 intake valves with the specific cleaner and tools they make for it. On these vehicles the intake manifold can be taken off and put back on in an hour by people with competent mechanical skills. You’ll be able to clean 7 of the 8 valves right away after popping off the intake and determining which valve looks open. To clean the open valve you will have to attach a long bar to the crank pulley and turn it (IN THE CORRECT DIRECTION!!!) in order to close the final valve and clean that one too. Once finished you pop the manifold back on and you’re done.

Now having said all that, these engines don’t seem to suffer from super caked up intake valves like their German counter parts do. I’ve seen examples of people going 100k + miles and the valves are only mildly caked up. In fact the examples I’ve seen posted on here both at low miles and high miles look nearly identical. I truly don’t believe this is an issue on the GM LT engines. And if they are, this is one of the more simple engines to clean them on.

Okay. Thanks.

I have done an intake valve cleaning on two different Audi's just as you described.

Removed intake manifold to get to the valves and then used a combination of carbon cleaner, wire brushes, and picks to manually clean the valves that are closed. Rotate engine and clean other valves

One of those Audi's was a 2008 with the 5.2 liter V10. Total of 20 intake valves so it took a while. (On a side note, that engine is a mechanical marvel/nightmare of complexity; 2 intake valves + 3 exhaust valves per cylinder, total 50 valves, 4 cams, 10 oxygen sensors, 4 timing chains, etc.)

For now, I will likely just run some CRC DI cleaner and call it good. Maybe I will pull the intake manifold when I get near 50K miles and inspect things.

[Jeb114]

[m6-lt1]

Originally Posted by Spaceme1117

For now, I will likely just run some CRC DI cleaner and call it a day.

I haven’t experienced this but I read on these forums not to do that. That method can result in large chunks of carbon falling off into the cylinder bore and damaging the walls. Not sure if it’s true or not, just letting you know what I read. I’ll admit there is a chance the cleaner makes the deposits soft when they fall off in order to not cause any damage however I haven’t seen anyone test out this theory yet so I can’t say it’s true or not. I would just do nothing, or pull the intake to clean it. For now, I myself have done nothing based on pictures I’ve seen of people’s intake valves after 100k. Just an FYI, the LT1 is basically the same as the truck motors minus both intake and exhaust manifolds. There are thousands of truck motors on the road with high miles and I haven’t seen any of them have excessive valve coming issues. You can add a catch can if you want however NO catch can will catch 100% of the oil going to the valves.

[Tim M]

Here is my 27,000 mile valve condition...and without a 'catch can':



Definitely not anything to lose sleep over...forum blows this stuff out of proportion.

[Gunkk]

Originally Posted by Spaceme1117

Is this even much of a problem on these engines?

No. Don't waste a dime of your money or a lose wink of sleep over this.

GM LT1 and LT4 engines made during and after the 2015 model year do not have the carbon build up issues that plagued many early 2010's GDI cars (BMW, Hyundai, etc.).

There has been quite a bit of of Arguing_On_the_Internet(TM) about this subject recently on these forums in various catch can threads, but actual photographic evidence of extreme buildup to the point of measurably affecting performance and requiring walnut blasting to correct on stock LT1s and LT4s is very very rare to the point of not existing.

And even in the very few pictures anyone has posted of buildup on stock cars it's nothing close to the horror stories you see and hear.

One of the very few rare pics of a stock SS with reasonable miles is from our very own forum member EDFHOBBIES's wife's SS at 40k miles:
https://www.camaro6.com/forums/showp...9&postcount=42

Pretty much the same as Tim M's above.

[Jcwoodhit]

Originally Posted by m6-lt1

The best way to clean them is to pop the intake manifold off and manually clean the 8 intake valves with the specific cleaner and tools they make for it. On these vehicles the intake manifold can be taken off and put back on in an hour by people with competent mechanical skills. You’ll be able to clean 7 of the 8 valves right away after popping off the intake and determining which valve looks open. To clean the open valve you will have to attach a long bar to the crank pulley and turn it (IN THE CORRECT DIRECTION!!!) in order to close the final valve and clean that one too. Once finished you pop the manifold back on and you’re done.

- I know this is an old post, but I was inspecting and cleaning my intake valves today because I'm suspecting a sticking valve due to rough running. I noticed you said all 7 will be closed except for one. Well all mine were closed except 2? Cylinder 3 was fully open, but cylinder 4 was halfway. Is this my culprit you think?

Now having said all that, these engines don’t seem to suffer from super caked up intake valves like their German counter parts do. I’ve seen examples of people going 100k + miles and the valves are only mildly caked up. In fact the examples I’ve seen posted on here both at low miles and high miles look nearly identical. I truly don’t believe this is an issue on the GM LT engines. And if they are, this is one of the more simple engines to clean them on.

I was cleaning my intake valves today (thinking I have a sticky valve due to rough running) all were closed except 2? Cylinder 3 was fully open, and cylinder 4 was halfway open. Think this is my culprit? I noticed you said all but one would be fully closed. Any input would be greatly appreciated!

[bishopts]

I had right at 100k on mine when i pulled my left head off to replace it. The valves weren't carboned at all. One was definitely bent but not dirty lol.

[bishopts]

Originally Posted by Jcwoodhit

I was cleaning my intake valves today (thinking I have a sticky valve due to rough running) all were closed except 2? Cylinder 3 was fully open, and cylinder 4 was halfway open. Think this is my culprit? I noticed you said all but one would be fully closed. Any input would be greatly appreciated!

Read more and watch videos on how camshafts work and firing orders. You're not understanding the mechanics of it.

[wang970305]

you can get a used mishimoto or mighty mouse catch can when someone is selling their car. i empty my catch can every time I change my oil. it would catch some oil but my IM is still relatively oily.

[Rich292]

Definitely do NOT do an intake valve cleaning.

I've looked at a number of forum posts about intake valve deposits on these engines, including the nearly identical truck engines.

Lots of people will tell you that they have oily intakes, that their intake runners are dirty, buildup on the valves, and so on.

The problem is that everyone thinks the intake runners should be completely dry and silver like the day they were made. Yes, they turn black. You might even get a tiny buildup on the valve stem from some oil passing by the valve stem seals.

But here's the important thing: None of it makes any difference and none of it matters. On all these posts, including the photos in this thread, what you see is a microscopically thin black coating on the metal parts. That coating is so thin you can easily see the casting grain of the intake runners through the coating. So that coating is much, much thinner than just the surface roughness of the metal in the heads. That means it is not affecting flow or the operation of the car in any way. Even a little ring of buildup on the intake valve is nothing to worry about. It won't interfere with airflow or have any impact on the power, efficiency, or life of the engine.

Opening up the intake and messing around with the valves could, though. There's always potential for some debris to fall into the engine, or for you to be cleaning without realizing the valve isn't 100% closed and seated. So you are taking a risk with no benefit whatsoever.

Unless your car is experiencing some kind of issue like a check engine light or a noticeable difference in how it drives, I would leave it alone.

[Jcwoodhit]

Originally Posted by Rich292

Definitely do NOT do an intake valve cleaning.

I've looked at a number of forum posts about intake valve deposits on these engines, including the nearly identical truck engines.

Lots of people will tell you that they have oily intakes, that their intake runners are dirty, buildup on the valves, and so on.

The problem is that everyone thinks the intake runners should be completely dry and silver like the day they were made. Yes, they turn black. You might even get a tiny buildup on the valve stem from some oil passing by the valve stem seals.

But here's the important thing: None of it makes any difference and none of it matters. On all these posts, including the photos in this thread, what you see is a microscopically thin black coating on the metal parts. That coating is so thin you can easily see the casting grain of the intake runners through the coating. So that coating is much, much thinner than just the surface roughness of the metal in the heads. That means it is not affecting flow or the operation of the car in any way. Even a little ring of buildup on the intake valve is nothing to worry about. It won't interfere with airflow or have any impact on the power, efficiency, or life of the engine.

Opening up the intake and messing around with the valves could, though. There's always potential for some debris to fall into the engine, or for you to be cleaning without realizing the valve isn't 100% closed and seated. So you are taking a risk with no benefit whatsoever.

Unless your car is experiencing some kind of issue like a check engine light or a noticeable difference in how it drives, I would leave it alone.

this has been going on for a while now, nobody can figure it out. I've replaced everything, and when I say everything I mean EVERYTHING. Bucks at light throttle, bogs at wot, doesn't make the power it should, everything mimics a vacuum leak but there is no vacuum leak. No cel, no mods other than Rotofab intake and yes I switched back to OEM no difference. Crazy negative ltft both banks. I guess I'm just going to have a leak down/compression test because that's the only thing to have done at this point idk

[bishopts]

Originally Posted by Jcwoodhit

this has been going on for a while now, nobody can figure it out. I've replaced everything, and when I say everything I mean EVERYTHING. Bucks at light throttle, bogs at wot, doesn't make the power it should, everything mimics a vacuum leak but there is no vacuum leak. No cel, no mods other than Rotofab intake and yes I switched back to OEM no difference. Crazy negative ltft both banks. I guess I'm just going to have a leak down/compression test because that's the only thing to have done at this point idk

Compression test would definitely get you some useful information on a direction to go.

Look at your fuel pressure and regulator command percentage.
Ive done a good amount of high pressure fuel pumps. Sometimes they run fine and just have rich codes. On those if you change the oil the fuel trims will be good for a little while. The pumps leak fuel into the oil and the pcv pulls the fuel vapors in and ends up running rich.