Screws came loose inside of intake manifold

[Daves_X]

Good Morning,

I was rebuilding the motor to my car over the weekend and I noticed as I was going to put the intake manifold back on that there was something moving around inside loose. I opened up the intake manifold to find that the flappers on the chamber exchange were falling off. I had two completely off where the screws were floating around inside the intake and the others were coming off and or were loose. My concern is: Is this common, is this something that others should be worried about. What if they got sucked down into the motor it could have caused catostafic damage. :frown: I am attaching a picture to point out what I am talking about.

Thank you for your time

Dave

 

[JeffShoots]

Never heard of this happening but that is your VVS system? It's the variable air track and the flaps redirect the air at low or high revs.

I would hope the factory used a thread locker or something to hold the screws? Are you the first to open this up on your car?

Could another owner have messed this up before you had the car or are you the first owner? A lot of turbo guys gut all that out for more air flow.

 

[Larry Bastanza]

I have seen this before, not sure I would call it "common", but you are not the first.

My $.02

LarryB

 

[scorp965]

This happened on a local car in SoCal, and did cause catastrophic damage.

 

[NSXDreamer2]

On 2nd track day of nsxpo, I noticed my nsx making some weird noise besides the 'normal' tick tick tick....

Shad @ Driving Ambition listened to my motor, and he's the one who told me about this. He just rebuilt an engine from this very failure. I haven't had a chance to pull the nsx out of my garage since then, but I'll keep you guys posted.

 

[JeffShoots]

This happened on a local car in SoCal, and did cause catastrophic damage.

On 2nd track day of nsxpo, I noticed my nsx making some weird noise besides the 'normal' tick tick tick....

Shad @ Driving Ambition listened to my motor, and he's the one who told me about this. He just rebuilt an engine from this very failure. I haven't had a chance to pull the nsx out of my garage since then, but I'll keep you guys posted.

That sucks

NSXDreamer2 your car was the LOUD red with the wing? If so how did you hear anything :biggrin:

 

[NSXDreamer2]

That sucks

NSXDreamer2 your car was the LOUD red with the wing? If so how did you hear anything :biggrin:

I of course couldn't hear anything inside the cockpit, but I have the habit of lifting the engine cover up after every session. (venting the engine heat, checking the oil later, and the cover double up as a visor from sun) and then I noticed that noise.

 

[Big_D]

Thats scary...

I think it would be a good idea to document the mileage of the cars that this happened to so we can get an idea of how common this really is.

 

[UnhuZ]

one more reason to remove them all and smooth the intake manifold interior...a job SOS used to do but don't nowadays.....

i wonder if removing all those littles TBs and related moving mechanical parts, will somehow trigger any CEL...or if the system is purely mechanical and there isn't a sensor to report problems to the ECU, then i just think it would be fine....

 

[goldNSX]

That really sucks! What the exact desciption of the sound it makes?

 

[scorp965]

Thats scary...

I think it would be a good idea to document the mileage of the cars that this happened to so we can get an idea of how common this really is.

It was a 3.2L engine with low miles in the case I mentioned... it was something of a dual purpose track/street car, so probably a fair amount of high-rpm driving, but no other wear to mention. A few other screws were loose, one of them fell off, and was ingested, leading to bent valves, etc.

Perhaps a line worker had too much sake, and forgot the thread lock?

 

[NSXclear]

Dave_X,

I've been trying to get in touch with you. I tried to PM you and email you without any responses.

Can you please send back the tools that I lent you over a year ago, when I offered to let you borrow them to fix your car in San Diego? I would like to have them back, please. You told me that you were going to mail them to me when you moved away without letting me know, but I still have not received them.

Ethan
[email protected]

 

[Big_D]

It was a 3.2L engine with low miles in the case I mentioned... it was something of a dual purpose track/street car, so probably a fair amount of high-rpm driving, but no other wear to mention. A few other screws were loose, one of them fell off, and was ingested, leading to bent valves, etc.

Perhaps a line worker had too much sake, and forgot the thread lock?

Thanks for the info. The more information we can post the better. Hopefully this will be an infrequent occurance.

 

[NSXDreamer2]

False alarm!!! finally taking it off, everything is tight in there... so sorry guys, my previous post weren't constructive at all.

in one way, it's a relief that whole butterfly valves are all tight and solid, in other way, damn, then where is the noise I heard coming from?? hopefully it's just dirty LMA..

btw, one member mentioning taking the whole thing off for FI engines and gaining as much as 20 hp... Is that true? If so, can we just take these off too, even if there's no gain, we don't need to worry about things flying into the cylinder any more...

 

[scorp965]

btw, one member mentioning taking the whole thing off for FI engines and gaining as much as 20 hp... Is that true? If so, can we just take these off too, even if there's no gain, we don't need to worry about things flying into the cylinder any more...

You gain more than 20hp, in my turbo nsx, we gained 32hp, and a nice bump in torque, by simply disabling the system (butterflies still in place)

The problem with the VVIS is its designed to work under vaccum, so in an NA motor, it works as designed, and produces midrange torque - when you put a supercharger, or turbocharger, on the car, the valves lock into an angled position and are an intake restriction. On CTSC cars, the intake manifold is already replaced, so the VVIS has been removed. On GMSC cars, or turbocharged cars, it needs to be disabled, or preferably removed.

You can replace the VVIS system with a blank plate SOS produces (or used to produce), or you can simply remove them, and grind down the sides to smooth everything out.

If you have a CTSC car, this is already done, if you have an NA car, you will lose power by disabling the system.