SCREWED! The Tale of my "Rebuild" (long winded, sorry slow day at work)

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11 June 2009
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Location
East Orlando
Good day one and all! I believe this is my first real thread i am starting and am doing so with hopes of sparing someone my experience...

...one beautiful sunday afternoon, 11/13/11 to be exact, i was driving home from the Winter Park Concourse de Elegance, reminising on the cars at that show and at the Simply Clean 3 event the day before when my car cut off when I came to a stop at a red light :frown:

After the second or two it tooked to process baby (thats my cars name) had shut of i turned the key to the ignition on switch didnt observe anything awkward and proceeded to turn her over. What happend next i can only describe as how id probly feel if my wife told me she was pregnant :tongue: CLANK CLANK CLANK CLANK the engine was knocking!?!?!?!?!?

I decided to limp into the plaza pass the intersection and await further review. A family friend / mechanic came by and after playing 21 questions w.me ask me to turn her on and then quickly had me cut the engine seeing that it seemed to be knocking. :eek:

After 2 tow trucks failed to show i had a 3rd tow to his shop he was kind enough to give me the keys to. Monday morning we went thru the routine and checklist / process of elimination.... consulting with Nabil @ First Class Automotive (THANK YOU SIR YOU ARE A TREMENDOUS HELP ASSET and MORE TO MYSELF THIS COMMUNITY :smile:)

The process of elimination took us from the bottom (oil pan off, checking the crank, rods, etc.) finding nothing but a clean block and nifty writtings on the rod bearings. To the top removing the cam holder thingies to find nothing again. :frown:

After replacing the rod / main bearing (since i was in there right :wink:) we turned the engine on and we had it again CLANK CLANK CLA..... then, it was gone. VERY confusing but we were able to keep the motor running long enough to go thru a few other processes one of which compression test on the cylinder to which we found #2 had VERY little, the same cylinder my buddy had been pointing to all along but wasnt able to find any evidence or cause (i am excluding the details on various test done initially suggest by him and Nabile, oil pressure etc etc).

So with no compression into the motor we went. I pulled the motor from the car and we went into seperating the heads and at long last there it was.... after many trips to Nabils shop and guesses we finally found where the problem was. The number 2 piston was pitted at the top on both ends.

piston-1.jpg


We thought that the valves may of been hitting but when we looked at the bottom of the head the valves seemed find but the bottom of the head had the same pitting. My buddy advised he has seem that often in ford focuses the loose the valve seat into the cylinder, so we had the cause, we thought....

After checking the headers and cat for the piece of metal and coming up empty handed i dove into the intake manifold. I can not describe the feeling of disappointment and anger :mad:/:frown: when i open up the plenum and saw this:

vvis.jpg


The FAWKING vvis butterfly valve screws came loose!>!$%^@#%^(*!!!!!!

Two screws GONE!?!?!?! The other two holding the loose plates on loose themselves ready to give as well. I flipped intake over and out falls one of the screws intact... the other screw you ask, in two seperate... flattend pieces.

This scenario is referenced in these two threads but i had never noticed or come accross them:

sos<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /><o:p></o:p>
http://nsxprime.com/forum/showthread.php?t=154928&highlight=vvis

daves_x<o:p></o:p>
http://nsxprime.com/forum/showthread.php?t=112761&highlight=vvis

So hopefully my thread will be seen by someone before its too late and someone else and their motor get screwed... (insert rimshot here) :rolleyes:

Anyone with the know how definetly get in there and put loctite, superglue, gorilla glue ANYTHING to prevent this or.... have them remove them completely, maybe Nabil can do a group rate lol. I for one just removed the plates and will deal with the possible power loss in the midrange until im sc'd :biggrin:

*When this happened i was at 107k miles, my car is daily drivin with the random spirited runs with the local group sporadically thru the year. Whether you 110% with maintanence or never change your oil this scenario is possible i would say*

*UPDATE* Also not that i was surprised to hear this, the machine shop let me know that a intake valve was indeed bent as well *UPDATE*

Sigh...x
<o:p></o:p>
 
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Sorry to hear about your misfortunes, but with every motor failure one can take solace in the opportunity to BORE AND STROKE!


Hope to see you and your car up and running soon!
 
I'sorry to hear about your troubles with your NSX. Can you provide some mer details about your Car...like
- Mileage
-Type of use
- Any Engine Mods
- Know maintenance history
- Last three Digits of your VIN
ETC....

The reason I'm asking, because I also have a 1997 NSX and would like to have these screws checked and secured on my car.


Thanks, Bram
 
I hate to hear about your misfortune. This sh!t just shouldn't happen. Obviously it's a manufacturing defect. I wonder if Honda would be of any assistance with this? Just when I think I have my car all sorted out, here comes something else to worry about (should I take it apart and remove this - or leave it in and risk it?). If this car wasn't so damn fun to drive I'd dump it - but then again - I'd have to get something else, and I'm sure just about anything else would be worse.
Driven to madness -
 
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I'm so sorry to hear of your misfortune. It's quite sad and unfortunate.

If you're FI, there's no reason to have the VViS. For everyone else, I don't think anyone would think otherwise if you just did the VViS eliminator kit. Even if you locktite the screws the risk is still there though somewhat lessened I suppose.
 
Sorry to hear that! I actually discovered the same thing when doing a rebuild on mine recently. There were only 3 or 4 screws out and somehow they were still just sitting there in the intake. At that point I had only had the car for a few weeks, it makes me cringe to think how long it had been like that... My car had about 80k miles at that point. It might be worthwhile for anybody with a decent amount of miles to check this, it could save you a whole lot of trouble down the road. You can always just delete the VVIS, thats what I did:biggrin:
 
Sorry to hear about your car, it's an na2 right. Can someone tell me the benefits and negatives on eliminating the vvis. Also what's the process involved in removing the vvis?

Thank you
 
This post should make every owner that hasn't done it already, pop it open and check every screw or do the delete option.


Curious about prior poster's question...
what are pros/cons with VVIS and without VVIS?
 
VVIS_dyno_chart.jpg


From what i gather the above image shows that na cars (non sc/turbos) loose mid-range power. This is from the sos thread i initially linked. Again just my interpritation i may be way off lol

waiting for the wise ones to chime in :biggrin:
 
I'd also like to know if getting to the VVIS to check/tighten the screws is a DIY project or something a professional should do.
 
I'd also like to know if getting to the VVIS to check/tighten the screws is a DIY project or something a professional should do.

Would you be comfortable removing and refitting the intake manifold?

The Intake Air Bypass(IAB) and internal VVIS plates and damn screws are underneath the intake manifold

good time to refresh the gaskets, clean, and polish stuff while you are in there

The smart guys can chime in on the process and gotchas
 
Which Intake manifold gaskets will need to be replaced? I assume just #5 and #6 ( are #2's are metal so can be reused?)

I do realized some other parts like the EGR / inejectors will be removed and will need new gaskets as well.

Also will red loctite stand up to engine temps or is there a better thread locker for this application? I don't foresee ever wanting to remove the screws/plates.


nsx_IM_gaskets.jpg
 
WOW I think I have something new to worry about thanks alot.. LOL

I would have never thought they would just slowly over time unscrew on their own.

I would think Honda torqued them to spec there for would never happen.

has anyone else heard of this?

next time I take off my intake manifild I will def double check them.

wow Im glad you got her back and running.

did you ever find the other screw?
I bet you its in the cats all banged up just resting waiting to be found.
 
WOW I think I have something new to worry about thanks alot.. LOL

I would have never thought they would just slowly over time unscrew on their own.

I would think Honda torqued them to spec there for would never happen.

has anyone else heard of this?

next time I take off my intake manifild I will def double check them.

wow Im glad you got her back and running.

did you ever find the other screw?
I bet you its in the cats all banged up just resting waiting to be found.

Be a few more days before im back up and running but I'm a lot closer than when i started not know what happened lol. The screws, I found both in the intake manifold, one was intact and the other was flattened so it got sucked in and spit back out =' (

2011-12-08113159.jpg
 
Less than 30 days to diagnose and repair this type of failure is quite prompt.
I would be scared to ask for the bill.
 
Wow! This thread has me worried, I got close to 150k on my '92 and I am seriously considering pulling the Intake manifold to check on those little bastards before its too late!!
Now in trying to think of a logical way that these screws would first come loose im pretty sure engine Vibration and the open and closing motion aids in there backing out. I have a exedy twin disc and it chatters ALOT moving from first gear so That's not ideal. Also if you visit the track alot and your C30a or C32b stays comfortably besides redline for hours a day I would recommend a look see! So add those criteria to the "Pull the Manifold and check it list"
Now other cars with stock clutches and no track time have had them loosen too so don't pop the champagne yet.

As for removing the VVIS completely, its one way to eliminate the possibility, but I think leaving it in place for most NA nsx's is the best way to go.
For everyday driving where your rpm rarely go past 5500rpm the added torque of keeping the VVIS system intact is some what priceless..I think more so for the 3.0 na1 crowd.
I think the real question for Naturally Aspirated NSX owners is how Soon cAn I check the bolts and how can I insure that they never back out again....
My 1.9 cents!
 
Which Intake manifold gaskets will need to be replaced? I assume just #5 and #6 ( are #2's are metal so can be reused?)

I do realized some other parts like the EGR / inejectors will be removed and will need new gaskets as well.

Also will red loctite stand up to engine temps or is there a better thread locker for this application? I don't foresee ever wanting to remove the screws/plates.


nsx_IM_gaskets.jpg

You will need #5, #2(2x), #6

Good time to thoroughly clean the manifold + EGR, Don't forget to loctite those screws as well!
 
I have a spare IM + TB from a 95 on the bench, so I went out to the garage to take a look to see if those two gaskets #5 and #6 are reusable and this is what I found

IMG01414-20111208-1448.jpg


IMG01415-20111208-1448.jpg



One of the other plates was also loose (both screws). The rest were tight. There is one missing screw. Sad part is this IM I'm guessing came off of the motor that's in my car now. I think I would know if it was a problem at this point, but still. :eek:

Anyhow back to the point at hand, the gaskets could probably be reused okay. Mine seemed dry and not hardened / crusty at all (reported 60-70k mi), but I'm going to replace them. I'm probably going to reuse the 2 x #2 gaskets if the ones in my car are in this shape since those are ~$50 a pop and were supposedly changed by the PO.

In response to seeing it with a scope, it's possible from the look of it to come in the TB. It would be slightly tricky to get it to go into the last 2 cavities, but possible. Either way though - loose/missing or not, aren't you going to go and fix this anyways? I honestly wouldn't wait after what I've seen.


[edit] BTW it's a piece of cake to disassemble once the IM is out of the car. So if you're comfortable removing the injectors, you can do this.
 
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Dude, worst nightmare, so sorry :( /// bUt am sure you car is going to be bad as soon soon!
 
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