*help* Broken mounting bolt, lower plenum! Where to replace?
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*help* Broken mounting bolt, lower plenum! Where to replace?
So, installing the Motordyne Thermal gasket set and plenum spacer, I just broke one of the long bolts that mount the lower plenum to the head. I wasn't overtightening, first off ... maybe it went in strange, but I was on the step where you tighten them to 110 in/lb, and it just CRACKED!
Where can I get a replacement bolt ASAP?! Can anyone tell me what size, or spec to look for?!? I am screwed, as I need this car tomorrow.
Where can I get a replacement bolt ASAP?! Can anyone tell me what size, or spec to look for?!? I am screwed, as I need this car tomorrow.
#2
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Originally Posted by neur0sis
So, installing the Motordyne Thermal gasket set and plenum spacer, I just broke one of the long bolts that mount the lower plenum to the head. I wasn't overtightening, first off ... maybe it went in strange, but I was on the step where you tighten them to 110 in/lb, and it just CRACKED!
Where can I get a replacement bolt ASAP?! Can anyone tell me what size, or spec to look for?!? I am screwed, as I need this car tomorrow.
Where can I get a replacement bolt ASAP?! Can anyone tell me what size, or spec to look for?!? I am screwed, as I need this car tomorrow.
After reinstalling all but the one bolt I drove around for a couple days and it wasn't a problem. You could probably do the same so you can drive it to sears and get a bolt extraction kit.
PMed.
Tony
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Originally Posted by Hydrazine
You can drive the car without one of the bolts. (I know. Some time back I did the same thing when untightening the stock bolt the first time. The aluminum was still quite warm when I did it so it was my fault.)
After reinstalling all but the one bolt I drove around for a couple days and it wasn't a problem. You could probably do the same so you can drive it to sears and get a bolt extraction kit.
PMed.
Tony
After reinstalling all but the one bolt I drove around for a couple days and it wasn't a problem. You could probably do the same so you can drive it to sears and get a bolt extraction kit.
PMed.
Tony
You said it was an M6 bolt, with a 1mm thread pitch. Do you know what length? I'm going to bring it with me, to compare, when I go to the hardware store.
Thanks for the lightning fast response!!
I'll post back here what I come up with...
#4
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If you can get it from Infiniti or Nissan I recommend thiers. M6 bolts are quite uncommon in hardware stores. And they are much more difficult to find in the automotive grade high strength alloy 10.9.
And although you can use 8.0 or similar, 10.9's are much prefered in that location.
Also, let your engine cool down real good before doing the work. The aluminum is less sticky at lower temps.
Tony
And although you can use 8.0 or similar, 10.9's are much prefered in that location.
Also, let your engine cool down real good before doing the work. The aluminum is less sticky at lower temps.
Tony
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Found some bolts that were M6 x 1.00 at a 10.2 strength. Should work OK.
Strangly enough, my engine was bone cold. It had been sitting overnight in the garage, for at least 14 hours.
Strangly enough, my engine was bone cold. It had been sitting overnight in the garage, for at least 14 hours.
#7
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Originally Posted by neur0sis
Found some bolts that were M6 x 1.00 at a 10.2 strength. Should work OK.
Strangly enough, my engine was bone cold. It had been sitting overnight in the garage, for at least 14 hours.
Strangly enough, my engine was bone cold. It had been sitting overnight in the garage, for at least 14 hours.
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Tony - Mine broke on the way IN. Since I was turning the tq wrench so slowly, I felt it as soon as it broke, and slowly backed it out.
The bolt was cracked right in the center of the threads, and was almost broken completly off. None of it was left in the lower plenum, thank god!
The replacement bolt I got worked like a charm. Perfect fit, and no more snapped bolts! Everything is back together, and I didn't even have any air leaks!
The spacer is awesome... I definatly feel some more "pep" in the acceleration. After I do a few more mods this month, its going back on the dyno, to compare to my baseline... we'll see!
The bolt was cracked right in the center of the threads, and was almost broken completly off. None of it was left in the lower plenum, thank god!
The replacement bolt I got worked like a charm. Perfect fit, and no more snapped bolts! Everything is back together, and I didn't even have any air leaks!
The spacer is awesome... I definatly feel some more "pep" in the acceleration. After I do a few more mods this month, its going back on the dyno, to compare to my baseline... we'll see!
#9
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For good pre/post testing it is best to do the install on the dyno of course, but this understandably impractical for most. The next best thing to do is slam the accelerator from 1500 RPM to redline several times shortly before going into the shop. This will put your ECU into performance mode. Then once you get on the dyno do a ECU reset.
This will help keep your ECU from going into granny mode. If you can keep the ECU in the same mode every time when you dyno you will get the best benchmarked results.
Tony
This will help keep your ECU from going into granny mode. If you can keep the ECU in the same mode every time when you dyno you will get the best benchmarked results.
Tony
Last edited by Hydrazine; 10-09-2005 at 10:25 PM.
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I wish there were a better way to reset the ECU. It took me almost 20 mins to get it done ONCE tonight! Someone needs to invent a switch that resets the damn thing!
Thanks again for all your help Tony!
Thanks again for all your help Tony!
#12
I did the same but my bit is left into the lower plenum. I went ahead and put it back together because I need the car. Its the left middle screw. what kind of bit extractor do i need cause it is deep in the bottom of the lower plenum. Is it ok to drive like this for now??
Last edited by Ace2347; 02-15-2016 at 08:36 AM.
#13
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You will probably suffer major vacuum loss, and drivabilty as well. Do a google images search on the type of extractor you think you might need, then clic over to the "shopping" tab.
Courtesy Nissan might be of help w replacement bolts.
972.231.2600
Courtesy Nissan might be of help w replacement bolts.
972.231.2600
#15
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please dont post the same thing multiple times....
https://my350z.com/forum/intake-exha...t-snapped.html
https://my350z.com/forum/intake-exha...t-snapped.html
#16
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VQ35DE Lower Plenum Bolt Nissan Part Number: 081B6-6701A
One of my lower plenum bolts broke too when I opened it up. I replaced it with with a 8.8 strength M6 x 75mm and used extra washers so the threads would tighten down as opposed to getting stopped by the unthreaded portion. Worked fine.
Now with plenum open again, and old OEM bolts being stretched/weak in the middle, I ordered some from a local Nissan dealer at $3.99 a piece, for next-day pickup.
Also found them on CZP for a better price $1.62. Would buy from here if not in a rush. Hope it helps someone!
One of my lower plenum bolts broke too when I opened it up. I replaced it with with a 8.8 strength M6 x 75mm and used extra washers so the threads would tighten down as opposed to getting stopped by the unthreaded portion. Worked fine.
Now with plenum open again, and old OEM bolts being stretched/weak in the middle, I ordered some from a local Nissan dealer at $3.99 a piece, for next-day pickup.
Also found them on CZP for a better price $1.62. Would buy from here if not in a rush. Hope it helps someone!
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Loud pop when installing plenum screws
I heard a loud pop when installing the center two (top and bottom) plenum screws. I fear I have overtorqued them, but neither broke off into the plenum, however, they no longer tighten like the other 4 screws. I am sort of scared that I've broken something! I've shut the hood for tonight and left it alone until further help form the community.
Any input is very much appreciated, and Thank-you in advance
Any input is very much appreciated, and Thank-you in advance
#18
Where did you get your bolts I have the same problem unfortunately
Tony - Mine broke on the way IN. Since I was turning the tq wrench so slowly, I felt it as soon as it broke, and slowly backed it out.
The bolt was cracked right in the center of the threads, and was almost broken completly off. None of it was left in the lower plenum, thank god!
The replacement bolt I got worked like a charm. Perfect fit, and no more snapped bolts! Everything is back together, and I didn't even have any air leaks!
The spacer is awesome... I definatly feel some more "pep" in the acceleration. After I do a few more mods this month, its going back on the dyno, to compare to my baseline... we'll see!
The bolt was cracked right in the center of the threads, and was almost broken completly off. None of it was left in the lower plenum, thank god!
The replacement bolt I got worked like a charm. Perfect fit, and no more snapped bolts! Everything is back together, and I didn't even have any air leaks!
The spacer is awesome... I definatly feel some more "pep" in the acceleration. After I do a few more mods this month, its going back on the dyno, to compare to my baseline... we'll see!
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