That knocking sound I encountered a couple of days ago might be more serious than I thought (sounds like metal to metal)

@ the track 2day after 3 runs (the last two taking it to 7000rpm), the car simply shut off on me, leaving me coasting in D after trying to park it. This happened when the car was @ low RPM.

Upon restarting it, the same knocking (again, sounds like metal to metal and fairly prominent/noticable) returns. Dave (black5spdmax) and Frank (max vq) think it may be something to do with the valvetrain. Or could it be the recently installed MEVI with a lacking EGR gasket is causing such a significant vacuum leak that the car runs too lean, hence shutting down, after being pushed WOT many times?

After taking it to 40km/h (just like after the first time I heard this sound a couple of days ago), the car runs normal and fine @ WOT on the hwy. Even took it to 160km/h no problem.

Any ideas to the causes/remedies of this problem? The car is running/sounding perfectly fine now.

 

I hope you didn't lose a butterfly valve and suck a few screws into your engine. There was a post on here not to long ago from somebody who had that happen. I can't remember his name. Search MEVI and see if you can find that post.

 

I thought only the 99SE-Ls had butterfly valves?

But for the original poster, I'd be betting on the valvetrain too. I'd almost be betting on a sticking valve since it doesn't happen all the time, and you hear the metal to metal noise.

 

Drew... he's got MEVI hence he's got butterfly valves.


Is this the same noise as was in the video titled Justin.mov? If so, you're screwed. That motor is toast.

 

yeah that video is justins (shoooter_j's) car.

the thing is the sound happens very rarely
on his drive home, the car was fine.
also, his knock sensor is dead.

btw...about the hardest stopping maxima in your sig...hehe
we had a max owner in toronto with 8 pot WP brakes with 14" rotors...

 

Dang. Aha but what pads did he have

That's weird that the sound is intermittent. Still sounds like something major.

 

Yea its only happened twice recently. Its only when i push the car, but I pushed it to WOT like 4 times 2day, running perfect?!

I'm gonna open up the VI either 2day or tomorrow and see if there are any butterfly valves loose.

 

Daniel: i hope you're not mad i posted this pic

he's selling them in the general forum...trust me, that thing stops on a dime with 5 ppl in the car

J: sorry to ***** up your thread
if you need any help im free after tuesday, just gimme a call.

 

Nice diagnosis of the problem...indeed it was what you said. Butterfly valves (the most right ones) broke off. I was only able to recover the valves, the 4 little screws are a lost cause.

Before jumping to replace/rebuild the motor, would a full engine flush or oil change hopefully flush those screws out?

 

possibly an engine flush...oil has nothing to do with it really...good luck. call some mechanics get there opions too.

 

How did the valves brake ?? its not like there under any stress...Maybe he didnt put the screws in tight enough, like a final tightening that your suppose to do, and when the ratteled loose, the VI opened and the screws went down in the engine...then the plate just sat in there gettin tossed around...because if i recall, the plates cant fit down that hole as long as the bars accross preventing it ??

-matt