Seriously.. Maybe time to open it up.

 

Im takin my cover off this afternoon man

-matt

 

Damn mecca, I didnt know you had 160+k on your engine! WHat are you gonna do? Rip everything appart and try to find the screw/make sure nothings damaged? And put red loctite on all those little suckers.

 

You were doing 145+ mph when the damn thing let lose and you drove it for alot of miles after the fact...I would think it pretty much ruined your engine

If the fact was that you started it one morning and it was making the noise, then i would say possibly you could be ok..but you were doin 145+ tacked out with the valves most likely OPEN

-matt

 

sucks

Good thing our engines dont cost too much money.

 

i pull my cover off every month and check and make sure the screws dont come loose

 

wow that sux man

 

Sorry to hear about what happened.

Your Max almost sounds like a tractor. Hopefully not much damage has been done. Keep us updated.

 

damn... that's definitely not good... I hope everything is gonna be ok with it, good luck!

 

This has always been a primary concern for me. If that screw gets digested into the intake port, your valves, piston, cylinder walls, or head is done. You might as well yank the motor and replace it with a used one. There isn't much sense in wasting $1500-2000 in engine work when you could spend $1500 and swap in a much lower mileage engine with no fear of a mechanic putting it together wrong.

I too used to locktite (red) on my screws and I check them periodically, however that doesn't mean they won't come loose. On the exposed portion of the screw thread (underside of the butterfly), I put a dab of heavy duty silcone just so the if the screw break loose, it can't back out.

If I get a "fun" car like a Mustang, I will be selling my MEVI because it's not worth the hassle sometimes (flakey rpm switches, potential vacuum tank problems, loose butterfly screws, etc). I will extrude hone my stock intake manifold and get 90% of the MEVI 1/4 mile gains with no worries.

 

Hey Mec, like I said I think that screw bent your valve on its way in the combustion chamber by the way the car sounds. Depending on what kind of metal that screw is made out of, it either vaporized in the combustion cycle or spit itself out the exhaust ports (don't think its in there anymore by this point). Let me know what you need help with and I'll walk you through it or get my hands on it.

~Keith

 

thanks guys for your sympathy.

As for my plans, i plan to go boosted again sooner or later and it makes no sense fixing this 160k+ mile engine up when i can get something of lower mileage for about same price, so yes i'm getting a new used engine.

As far as how this all happened, i was doing a little speed on the highway, maybe in the 80's - high 90's tops (this is after getting all exhaust leak fixed) and friends behind me say they saw fire coming out my exhaust. I also hear massive pop sounds as if heavy amount of gas was being pushed into the car. (still have to get tuned and i have SAFC set to Jay's 10 psi w/ mevi setup). I thought i was just running really rich so i didnt do anything about it and on my way home was when i did 145. I heard a different exhaust tone ever since the fire exhaust incident but never thought of engine issues. The car was loud that night but not rattling or anything, just sounded like exhaust leak. I dropped my friend off to school that morning and didnt really go at it cause i didnt know what was going on wit my car. As I make it home, about 5 blocks away from my house, my car just starts sounding like sh*T. Rattles, even my shifter was vibrating. it sounded similar to when i blew my tranny but with a much heavier tone. Finally got car home and thought low oil caused the issue but thanks to ian telling me to check butterfly screws this morning, i found out what was causing the issues.

I did use loctite (blue loctite i believe) but i'm a rare incident. Not too many people are FI taking the car past the 140 mark, sorry if i caused a major worry...i had to bite the bullet... It sucks. I'll be driving it one last time when i make my trip to get the engine swapped.

 

So, are all of the issues with the butterfly screws coming loose only a result from the Variable intake? Ot do you think it could happen to someone without MEVI? (I know it sounds like a dumb question, but just making sure.)

 

People without the MEVI dont have the butterflies at all....

:

I should ban you for that question.

 

i honestly have no idea

LMAO @ whoever changed the title of the thread

nice choice of words by me ehh?

 

Sucks Mecca, now you see the main reason I never got the mevi. Hope your back on the road soon gotta rep Maplewood, that town is beat. :-p

 

Just get a torch and a wire hanger. Melt some of the hanger on top of the screws. Cost 10 cents for the wire hanger.

 

holy crap! poor max! good luck on however you decide to fix your Max

 

vaporized? don't think so this is what may happen specially at 145mph with valves opening and closing very very fast

1- screw got in when exhaust valves were open thus it was spelled out of engine with minimal damage
2- screw got in while valevs were close thus it may have some damage on cylinder walls but again minimal
3 screw got in and got stuck between valves and where valves seats(ports) and it got stuck so valve can't no longer close all the way and this is whats causing or may have caused the erratic drive btw haven't see the video (56k at home) but again if the screw got in and out in just 1 cycle minimal damage was done but if it got stuck thats not good at all

 

yea i was there that day when maccas car became a flame spittin monster. i hope everything works out

 

so that means that valve got stuck halfway when combustion occurs so i bet he needs a new valve and maybe a new head

 

Replace the engine...
On an engine with 160K, its worth gettin an engine for $500 with 20-30K miles on it, and even spending the money to have it put in (about $800 tops) then to di*k around with replacing stuff, and paying for labor and hopeing metal didnt chip off and cause other damage on another part of the engine that wont show its ugly head till later on

-matt

 

^^^^ i agree, but i'm looking for more around 70k miles

 

I got a 97 maxima motor with 74K miles and a 1 year part and labor warrenty for $400.

 

i found a maxima motor with 67k miles for 500 shipped well i dont have to pay for shipping cause of location....

 

Damn mecca, so sorry to hear about this and I understand your pain. My engine ate a VI screw a few months ago, despite using locktite during installation (don't remember the color) This time around I had them tack welded just for peace of mind. Good luck with the new engine.

 

geez, hopefully that missing screw wont break anything major. good luck finding it, which it will be a ***** to find.

 

not even gonna bother trying to find it....just slap on new engine and forget about my f'ed up past.

 

You're putting the blower on the new motor right? Are you going to go without the VI with this new motor? As much as people say the MEVI is awesome, (great high-end, expecially with ECU) - there are so many issues, some people have trouble getting theirs to work right, and right here your mevi is the cause for a new engine, not to mention some people reported major HP loss in the low end and minimal gains in the high end . . . it just doesn't seem worth it to me.


Mecca, if you get the car running by next friday, we're (me, will, jeff, sakao + few other people that go to spring valley) planning on goin to E-town and get a few runs in.

 

no more mevi and no more SC, actually using money to get new motor and swap, but i'll be back, one of these days, once u go boost......

 

Your third senerio is also possible and one that I overlooked. This seems to be most likely what happened given the frequency the valves were moving at that speed; I was unaware of all the factors when he called me and told me what happened. I agree with what you said here, good observation man.

On a side note, knowing metalurgy and thermodynamics, if the screw was made out of brass, the intense energy from heat inside the combustion chamber (which would then flow into the closed system representing the screw assuming it made it into the combustion chamber) could have caused the brass to melt or possibly vaporize given the characteristics of this metal. This of course depends on how long the screw was inside the cylinder for, if it made it in, where it was inside the cylinder, etc., etc.. If it was steel, then it would survive.

So when's that motor arriving at ur place Mec?

 

after talking with a few friends from another forum they agree that the screw may not reach combustion chamber at all dut to size most likely it got stuck withing the valve shaft area

but like you said before it this screw is made out of brass with all that heat and the valve hammering it may got destroyed in pieces small enough to got it combustion chamber and then spelled out of engine by exhaust gases anyhow i'm almost sure that valve needs replacement and head may need some job too hopefully thats

any updates did you takes heads out of engine?

 

cars been sitting since the video, i'm only gonna make one more trip to friends house who will do install in exchange for some car parts and beer . I didnt want to take a chance of driving car and having it break down before i make it to the engine's final destination. Thanks for all the support guys.

 

if you do get the money would you get another mevi though?

 

Actually 99 have thos butterflies in the lower intake manifold stock. Some or all not sure

 

mevi does a lot for boosted cars so its debatable and i do plan to boost again...i guess i will but will do some serious welding or whatever so i never run into this problem again.

 

Krismax, are you serious? I'm asking, not questioning. I'm not picking up any sarcasm here but I have never heard this info before.

Mecca, sorry for your problem. This thread really makes me wonder if MEVI is worth it. I guess I need to make a chart.

Pros: Nice gains up top, great refined sound up top, .2 Sec/2MPH faster in 1/4.

Cons: Possibility of killing engine, loss of low end, running issues related with complications of the swap.

Hmm... A tough decision.

Judging from the look of that screw and the rest of screws Nissan uses I would guess it isn't brass. A lot of parts that color are simply dipped in a solution to help it resist corrosion. Someone got one lying around? Try to pick it up with a magnet.

 

from the beginning it was kind of known to not get mevi unless u drive on highway 24/7 or your boosted. You actually go slower with mevi unless u get ecu. The time the mevi helps u isnt long enough unless u have the ecu. But it does wonders for boost. It REALLY feels much better than Vtec.

Best feeling in the world..... 85 mph down shift into 3rd gear... = FLAWLESS

this is what makes me think of getting mevi again especially since i plan to get boosted again....

 

That is exactly where you know you've got the MEVI. Punch it from a roll at 4500rpm in 3rd and the car just keeps pulling and pulling. This thing doesn't throw you back any harder in the seat than the stock manifold, but gone is lack of power above ~5600rpms.

 

And the 00 lower IM had them also,i took them out completly and welded the holes shut . They look exactly like the ones in the MEVI and they have the two little screws in each buttfly also.