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I am new to this forum, and this is my first post. I am glad to know everyone, and receive help from the Infiniti gurus.
My car is the 2013 infiniti g37x coupe. Today I removed the engine cover to clean the plenum.
I am pretty sure everyone know that there are 5 screws to hold the engine cover down. The moment I removed the center screw, suddenly I heard the hissing noise came out from that screw hole, and when I touched it, it seems like a vacuum leak, and idle rpm dropped to 500rpm.
I wonder if it is normal that Nissan/infiniti designed their plenum with center screw hole created vacuum?
to note that the moment I put the screw back in, no more hissing noise, and also the idle rpm went back to normal.
I hope I can get help since I tried to search on the internet and found no luck thus far.
Thank you in advance
(the attached photo is just a random Infiniti/Nissan plenum I found on the web, and put a red arrow in to show everyone where the screw hole located)
I removed my plenum cover. Put the screw back in. No big deal.
Thank you for your response. So Infiniti/Nissan actually built their plenum that will create vacuum when that middle screw is removed. That is very interesting. I will plug it back then.
I suspect someone has used a bolt that is too long, and it punched through or cracked the bottom. It is not like this when new.
Just keep the screw in are you are OK. Some thread locker would help to ensure a perfect seal.
Can u post a pic because, I as well as OP, amongst a few others have this same plenum where the bolt has to be screwed in in order to avoid vacuum leak. Or can you remove the bolt in the middle and turn your car on and see if there is a leak?
I have received 2 different responses from Infiniti Dealer, which told me that I just put the bolt back in and problem solves. And from Nissan independent repair shop, said that was not normal, people drive without engine cover all the time.
To address this issue, I decided to buy a used plenum on ebay, cost me 120 bucks. While waiting for the shipment, I spent time to evaluate the current plenum, I actually used a small flathead screwdriver to poke into that screw hole, and it was not through and through!!! I suspected the crack (or whatever in there) was at the bottom and on a side of the plastic wall.
So yesterday night, I got some Epoxy High Heat JB weld (HighHeat Epoxy Putty | J-B Weld), and decided to plug that hole. It set after 1 hour, and fully cured after 8 hours. My preliminary concern was the heat from plenum can melt the epoxy, but since it was plastic, and the screw hole was aluminum instead, heat should not be transferred too much. So I ran the car for 2 hours yesterday night, freeway, uphill, downhill etc. and the epoxy was not melted (to note that I ran without engine cover).
I will keep everyone updated. I plan on "hijack" a infiniti G37 at some local dealers for test drive this weekend, and run to some parking lots, then remove that mid screw engine cover and see how it turns out!
I have received 2 different responses from Infiniti Dealer, which told me that I just put the bolt back in and problem solves. And from Nissan independent repair shop, said that was not normal, people drive without engine cover all the time.
To address this issue, I decided to buy a used plenum on ebay, cost me 120 bucks. While waiting for the shipment, I spent time to evaluate the current plenum, I actually used a small flathead screwdriver to poke into that screw hole, and it was not through and through!!! I suspected the crack (or whatever in there) was at the bottom and on a side of the plastic wall.
So yesterday night, I got some Epoxy High Heat JB weld (HighHeat Epoxy Putty | J-B Weld), and decided to plug that hole. It set after 1 hour, and fully cured after 8 hours. My preliminary concern was the heat from plenum can melt the epoxy, but since it was plastic, and the screw hole was aluminum instead, heat should not be transferred too much. So I ran the car for 2 hours yesterday night, freeway, uphill, downhill etc. and the epoxy was not melted (to note that I ran without engine cover).
I will keep everyone updated. I plan on "hijack" a infiniti G37 at some local dealers for test drive this weekend, and run to some parking lots, then remove that mid screw engine cover and see how it turns out!
Can u post a pic because, I as well as OP, amongst a few others have this same plenum where the bolt has to be screwed in in order to avoid vacuum leak. Or can you remove the bolt in the middle and turn your car on and see if there is a leak?
I don't use the engine cover and there is no vacuum leak at that threaded insert.
(double checked yesterday)
Did anyone ever actually figure out if this was a OEM designed thing or if it is a fault ? My center screw when removed definitely hisses when removed.
Did anyone ever actually figure out if this was a OEM designed thing or if it is a fault ? My center screw when removed definitely hisses when removed.
NOT NORMAL.
I'm been running without an engine cover for years now.
Yeah I've also come to the conclusion that it is not normal. Bolt must've been tightened too much to have punctured a hole through the Plenum. Get some Teflon tape and wrap is around the bolt threading and just screw it back into the Plenum. The Teflon tape should keep a good seal from leaks.
01-25-2017, 01:09 PM
