I'm heading out on this rainy morning to go golfing. About 1 mile away from the course my car starts to sound REALLY strange. Kind a smacking/flapping sound. I assume I'm loosing the SC belt. I put it into 5th gear and cruise the last mile at about 30mph into the parking lot (<1000RPM).

Get out of the car (still idling) and go take a listen under the hood. Its not the SC or belt, but rather the sound is coming from the valve/intake mainfold area.

Shut the car off. Just for the hell of it I take the cover off the MEVI (always keep a socket set in the car) and was shocked at what I found. 3 of the butterfly valves have come off! One of them is on top of the manifold, but 2 are *missing*. Also out of the 7 screws that came out, 3 are unaccounted for!

Now, I'm about to go outside to tear this bish apart. I assume the butterfly's couldn't get past the intake valves, but could they bend the valves?

I also assume that the screws did. Don't know how I'm going to handle this. They could have fryed in the combustion chamber (they're brass, aren't they), they could have gotten right out the exhaust valves, or they could be in there.

So, my plan for the moment is to take the MEVI and lower intake mainfold off, and re-assess from there.

Pictures coming.

I'd love some good advice right now.

 

Hopefully you recover the bufferflies and the screws just passed thru.

Use LOCTITE on the screws!

Do a compression check and leakdown test afterwards.

Goodluck...

 

Good news is the butterfly's didn't (couldn't) get to the point of making contact with the valves.

I'm about to take the lower mainfold off...no sign of the screws yet though.

Yeah...I didn't think of loctite.

 

yeah loctite saves your *** for lotsa stuff... hopefully your engine aint busted cuz of it man...

 

(Note all of these pictures are about 250KB)

This is what the MEVI looked like once I took the cover off:
http://www.ericj.org/maxima/img/mevi...m/IMAGE001.JPG

Notice there are 5 of the 7 missing screws on top of the mainfold...so I was wrong, I'm just missing 2:
http://www.ericj.org/maxima/img/mevi...m/IMAGE002.JPG

Butterfly valve through lower IM:
http://www.ericj.org/maxima/img/mevi...m/IMAGE003.JPG

No lower IM, you can clearly see a butterfly in the intake path for cylinder 3 (or is that 4):
http://www.ericj.org/maxima/img/mevi...m/IMAGE006.JPG

Both the missing valves:
http://www.ericj.org/maxima/img/mevi...m/IMAGE007.JPG

You can see the divider between the valves is what prevented the butterfly's from making contact with the intake valves:
http://www.ericj.org/maxima/img/mevi...m/IMAGE009.JPG

Current state of my car :
http://www.ericj.org/maxima/img/mevi...m/IMAGE012.JPG

At this point I'm still missing 2 screws, and there is no sign of them. I have to assume that they made their way into the combustion chamber. If they did get out the exhaust valves, they'd be long gone as I don't have a cat, so there isn't anything in the exhaust system to "block them in".

So, I'm looking for some advice. Do I re-assemble the car with the USIM, or do I venture into taking the heads off (which I've never done, nor do I know if I have the equiptment right now, but I'm not necessarly in a hurry to get this done).

Could I crank the car like it currently is and listen for strange "rattling" noises through the intake valves?

Advice?

 

Any reason I can't do a compression test with the car in its current condition? (No IM, no fuel system, no MAF, etc?)

 

Yet another update....pulled all the plugs, and they all look perfectly normal.

 

well those screws are quite small, you'll be lucky if they passed through without scoring or scratching anything

let us know how the compression check goes... kinda scary ehehe


good luck

 

Well, time for a new motor!

Compression is 170 on all cylinders (which was normal for this engine), but 100 on cylinder 3 (or 4, don't remember the numbering...its the middle cylinder on the right hand bank).

Putting the car back together now. Its should run, albeit not well. I need it to hold together for a few weeks until I get a new motor ordered installed...

Its obvious from watching that the loss of compression is occuring at the intake valves. I'd consider just installing new heads, but quite honestly I don't know if its worth it. For the price motors go for, I'd almost think its more economical to just go that route...

Again, open to advice.

 

Geez Eric that is just about as bad as it gets. After all your hard work on the install then boom. I feel for you its hard to swallow when everything is going well.

Its so easy for some stupid thing like that to happen. Like anything else hindsight would have caused you to do it a little different, unfortunately we don't have hindsight when we need it.

I almost did it last year at the track. I put my slicks on and hand tightened the nuts then lowered the car. Someone came over and started talking to me, I started doing something else and forgot about the nuts. Got almost all the way to the end of the 1/4 and I heard a noise so I backed off and the wheels started wobbling, I slowed as fast as I dared and just before it stopped the left front came off. Luckily no damage except some scratches on the inside of the wheel and a little somewhat embarassed, but the track guys were great and told me their tales.

Now you can make use of www.car-part.com unless you a good place already in mind.

Anyway sorry to hear bad news, hope you get a good deal on a new mill.

Jim

 

Got the car all put back together with the USIM this time. The car does start, and it does run. However, the slapping/ticking sound hasn't gone away.

Makes sense considering I know at least 1 valve is toasted. My car sounds like my old 91 Stanza did with its shot valve lifters. Its kinda reminds me of a diesl truck.

Any reason I can't keep driving this thing? Its going to take time for the engine to get here and for me to swap it of course...and I don't really care if I don't do further damage to the engine, as long as the SC and tranny stay fine (which I can't envision them being damaged).

What a day. Worst of all, I didn't ever get to play that round of golf.

 

This happened to my friend too, except only with one screw. He is now in the process of rebuilding his motor, glad that it occur cuz now I will pay extra attention to those screws. Sorry to hear about it though, good luck with the new motor.

 

DOH!

 

It's concievable that one or more of the screws is still down in the engine, banging around as it revolves. That or the valves are fuxored and bent and that's what you hear smacking around. Either way it doesn't matter... it's new engine time. When I get my car back I'm checking the tightness of all my screws. Sorry this happened to you it sucks when your car is hurting.

 

DAVEB showed me a pic of a blown VQ35 because of ONE TINY screw that came loose. Sucks that something so small can cause so much damage. Good luck... build a new motor with stronger internals.

 

this is going to sound stupid... but did you guys use lock tight on your screws? I did, but I didn't know if I should or not. Also... is it possible to put a screen in the upper IM to prevent these screws from falling into the lower IM?

 

Go get some coffee

 

Its wierd...

I cranked the car with the fuel system and intake manifolds off, and couldn't hear any strange noises. No smacking, no tapping, just normal cranking.

Put everything back together and the noise comes back.

I drove around a little last night, and noticed that the sound was getting better. Maybe I had 2 screws in there, and 1 found its way out?

Regardless, like you said, its new engine time.


I'll have pics of the damage of course after I swap. I'm going to tear this one apart.

No built engine. Doesn't seem cost effective. I am not going to make that much power with the SC, and if I do blow the next engine, its just another $500+my time. Just doesn't seem worth the killer money for pistons/rods, etc.

However, after I feel comfortable pulling/replacing and taking apart a motor...I may play with a project similar to Mardi's.

 

I used to like you...

Thanks for pointing all that out to me.

I do have a question about how bad is it if you didn't use the plastic bushing on the green rod?

 

EJJ, any updates? I lost two butterflies, but got them back. However, the four screws are lost in the engine. The engine however has stopped making the diesel noise Does that mean it could have passed through?
I will be doing a compression test very soon and checking my plugs

 

So two of you have lost screws that went to your motor. I got to weld the screws to mine then......


"LOCKTITE"

 

sorry to hear, but like you said, maybe this will get you comfortable enough to do some more things on your own

 

Not really. The diesl noise that you're describing went away within a few days. The car runs just fine, although its gradually getting harder to start, and idling worse by the day.

I also smell a lot of fuel when I start it, so I may not even be getting combustion on the f'd cylinder. However, I've been beating on the car (driving hard) a few times, and power feels just fine.

I've got a new engine in the garage, just waiting for the time for me to swap it in.

 

I guess I'll have to start sniffing for fuel and checking the idle, although everything appears normal right now.

Where did you purchase your engine btw? would ebay be a reliable source?

 

www.car-part.com

 

Yup, I found mine from there. I ended up getting it from Saw Mill Salvage near NYC.

 

How much did u pay? I was debating purchasing and rebuilding an LSD tranny for my car and swapping them in one day instead of removing and rebuilding my existing tranny (and having 2 weeks of downtime)... car-parts.com showed them all at $800. Maybe if I was more into modding I would do that for the LSD, but it's my daily driver and I don't really need the LSD. I got a 4x4 Bronco for winter driving.

 

Trannies go for a lot more than engines. I paid $500 shipped for my engine.

 

How many miles on it?