I installed the thermal iso gasket today, then was tightening the 6 bolts on the lower plenum using a torque wrench when one of them snapped

I then decided i'm just going to tighten all the other bolts by hand and put it back together. I'm on the final stages of getting it all together, just waiting for the silicone to dry a bit on the coolant control valve before hooking it all up.

It seemed like the center plate held by the 6 other bolts was pretty secure, but I'm not sure if that single hole will cause any problems? The lower part of the bolt snapped off, and I think the threads are stripped. I think you're supposed to drill out the bolt then re-thread it, but I don't have the right bit to re-thread it. I also don't want to mess up doing something like that, but will if I have to.

Does anyone know if this will cause a problem? Or am I safe to run it with that single bolt missing and a hole there?

 

It may be safe to run the car, as long as nothing is leaking. I would start the car, check for leaks, and if none are present, dont touch it.

Taking out that bolt is gonna be a PITA. Remove the upper plenum, remove the lower plenum, then block off all the cylinder ports, attempt to remove the bolt, without ruining the original hole for the stud, then re-tap it. YA right, I wouldnt even want to deal with all that, if not necesary. Others will disagree with my statement, but just because its broke, you dont always have to fix it.

 

Well I just started it up and no check engine light and everything sounded fine. What sort of leak might it cause? Any liquids that might run through there that can cause a problem?

Yeah doing all that work for that single bolt really will be a PITA. I am going to go for a drive and see if anything pops up. Anyone else have a similar issue?

 

I saw this happen on two bolts on a lower plenum. I wasn't the one that snapped off the bolts, but we were able to back them out and buy new bolts from a local shop.

Personally, I wouldn't drive my car around with a snapped off bolt in there...

 

how were you able to back them out? This info would be greatly appreciated!

 

They sell cool bolt removers at sears. Just ask someone there and you'll see it.

If you started the car, and it idled normal, then you should be fine. Its not like that bolt is gonna fall in the motor or mess anything up really, not a big issue in my opinon.

 

if it leaks - you'll know it is from the high pitched crazy loud sound. You can plug the leak with silicon

 

Agree.

 

I have one snapped bolt, I got really pissed that it happened too, the very first one on mine is missing its head part. So far ive only driven it 500 miles without any problems or leaks. I did make sure the others were a little more tighter to compensate for the missing one.

 

I have done this install also but didn't encounter any problems on my 03 but then again I hand tightened to recommended specs from the instructions Should be fine though as long as there are no leaks.

 

When re-installing my manifold i almost stripped one of the holes, but i was able to back out the bolt and re-tread it by threading the bolt threw the bottom, but i was getting ready to by a thread repair kit and by a new bolt.

i wouldn't be ok with having a broken bolt, i would take it off and put a good layer of silicon along with the gasket, if your worried about leaks and don't want to go through the trouble of everything else.

 

when a small dia. bolt like that snaps, it is usually due to over torqueing. once you get a feel for it, you can tell when you are twisting the bolt or just the shank, and never snap another one.
the threaded end that broke off should be very easy to pull out. yes, you want to have all those bolts in there. it may idle fine, but around a turn at part throttle you would never notice the leak. broken bolts on a motor are a huge no no. when a bolt breaks, the project stops till you fix it!! bottom line.

 

god just make sure you don tlose the bolt or any part of it. a couple months ago a guy on here did that (bolt might have gone into plenum or maybe other part of engine) and he had to replace his whole engine

 

replace the broken bolt, if it runs fine drive it to a local mechanic and they will get it out for you.

 

I drove the car around yesterday and nothing out of the ordinary, however I did pick up a bolt remover bit and I'm going to drop by the nissan dealership to pick up an extra bolt to put back in.

Driving the car without the strut tower brace feels completely different. Figured if I was going to open up the engine anyways might as well leave it off for now.

 

guy, same thing happened to me tonight....

did the nissan dealership end up fixing it all up for you?

 

Actually all I had to do was take apart everything again which was pretty quick since I knew all the little hoses and such that I needed to get off first. Took off the lower plenum and the lower half of the bolt was just sitting there so I just took a pair of pliers and twisted it out. I actually couldn't find a dealer that had the bolt in stock and didn't really have time to wait 3 days so I just got a lower strength one from Ace hardware. The other bolts had kept it from leaking so I doubt there will be enough force on that single bolt to snap it. If I ever go FI or do some major mods then I will replace it with the proper bolt.

Sear's bolt extractor kit looks like it would work pretty easy, but it was $30 and I'm glad I was able to return it. I wasn't about to go to the dealership with something like this since there wasn't any leak and I could probably fix it myself. Now if I stripped the threads then yeah I probably would take it to the dealership... though I don't know how they'd take it. The bolt is M6x1.0 70mm by the way.

 

Good stuff on that bolt. Glad you ended up getting that sorted out. Its not like your car was giving you any trouble though, with the broken bolt, right?

 

hey guy, so after you replaced the bolt everything started up fine?

did you install mrev alone... or mrev+spacer? in your thread you didn't say what you were installing?

I got my broken bolt out the same way... using a pair of pliers... but man o man was that scary when it snapped. I heard of guys snapping the bolt at 90in-lb of torque. What did you end up torqueing those 6 bolts to?

 

Yeah everything started up fine. I was able to run with just the 5 bolts, but figured I should get all 6 bolts in there. I was installing the ISO thermal spacer, so had to take the lower plenum off to get the gasket on there.

Figured while I was in there I would shave off a few millimeters on the front two intake runners and polish it smooth. Also polished the inside of the intake runners from the bottom, not the whole inside though. Haven't really noticed too much of a difference.

I just retightened them by hand, then when they were pretty snug, I used a torque wrench to turn them 1/4 turn. Has worked pretty well so far for all the bolts i've had to do.