Hi all, about 30k mile ago, I had my mechanic replace my plugs with NGK iridiums and a new Nissan lower intake gasket (and 6th gen rear valve cover). The car ran ok for a while but I started to notice a slightly rough idle.

This past weekend, I decided to replace the plugs with NGK Platinums to see if I can smooth out the idle. I went to one dealer to get the gasket and they were out of stock. And then I stopped in Hertrich Nissan in Dover, Delaware who had it in stock but wanted $52 for just the lower intake gasket!!! Damn!

So I reused the lower intake gasket. On removing the manifold, I noticed that one bolt was tighter than the rest so I am thinking that the gasket could be warped. When I pulled the iridiums, the gap on all six plugs was at .50mm. I can't imagine the tips eroding that much in 30k miles on all six plugs.

After I put in the platinums and torqued the manifold to 14ft/lbs. The car ran like a dream around town. Only when I was driving back to NYC did I notice the rough idle returning.

I think it's either the manifold gasket or my coils. I won't get a change to wrench on the car for another 3 weeks but was curious if anyone else experienced this.

PS - I felt good after I wrenched on the car. I haven't done it in a while.

 

Unless the dealer was trying to sell you some gasket kit, he was trying to rip you off.

But I think you are using incorrect wording, as you don't need to remove the lower intake manifold, just the upper intake manifold. For what you were doing, I doubt that you really did remove the lower intake manifold. Learning to speak Nissanese is not easy.

The list price of the gasket between the upper and lower intake manifolds (the one you really wanted) is $33.10, part number 14032-8J105, replaced by 14032-8J10A.

The lower intake manifold uses 2 gaskets, part number 14035-8J101, list price $25.60 each.

See this parts listing -

http://www.nissanpartszone.com/Page_...mponentsNo=140

 

I understand your angle but what if he is right and he actually is getting the lower intake manifold gasket? then $25.60 x 2= $51.20 ($52) so he might not be getting ripped off. Just saying.

OP After everything you said, I would suggest looking into the throttle body and getting into cleaning that before you go into guessing coils. IIRC coils would probably thow some codes and you didn't mention having any codes. It also won't hurt to also check into cleaning the maf while you are cleaning the TB.

 

Hi, you are correct. it is the upper intake manifold. I took the part number and price (quoted $33) that the 1st dealer wrote down with me to the 2nd dealer in Delware so that same exact part number and he actually quoted me $52. I asked if that was a mistake since it is only one gasket but he insisted that it was right.

 

Hi, I have no codes at the moment. I took a quick look at the TB and it didn't look too dirty, but I may give it a cleaning when I get a chance.