I just installed crawford V4 plenum but the plenum makes weird loud whistle noise. And my idle is not smooth after engine warmed up.
Is that normal?
Any idea what might went wrong?
Thanks.

 

You have a vacuum leak . You need to put at least 2 gaskets on . I had to use 3 gaskets to stop a boost leak at higher boost levels .

 

did you transfer the little black cap? i initially forgot to and had idle problems.

 

I did transfer the black cap from the oem plenum.
It sounds like a vacuum leak too but i couldn't find where it leaks.
The instruction says i didn't need to replace or add a gasket.

 

You don't. I did however replace my gasket, when I first put mine on. It is a vacuum leak of some kind. Call Doug at Crawford if you can't find it.

Lou

 

Make sure the 4 bolts are placed into the unused holes in the middle plate of the plenum. Those holes are used by the factory plenum, but not used by the Crawford. Add another gasket, and I bet you will be fine.

 

Did you remove the bracket labeled "M3" as per the instructions? That seems to be one of the most common leak sources.

Call Doug if you need more help.

 

Thanks for all your advice!!!

I actually reseal the plenum and now whistle noise is gone but there are kinda small noise coming from the plenum. It sounds like a something is hitting or running. The noise comes in when i rev it up. I can barely hear it but i would like to see if i messed up or not...
Is that a normal?

p.s I did everything what it says on the instruction.

 

I am having the same problem, any luck?

 

hey.. i just tried to install the new plenum cast version... 03 here... everything was put on right.. then i went to start it.. it kept stalling out... i found out.. the 2 bolts u put in the middle werent perfectly spaced as the oem version.... it was about 1/8 off.. and the bolt couldnt go down all the way into the plenum.. so it didnt work...
sux... all that to go on and off... any suggestions.. i think im gonna call them to replace it..?

let me know!

 

This is an issue I've never heard of before Are you sure everything is lined up? This is a cast part, and there should be no variation plenum to plenum. By all means, call Doug - He'll do whatever it takes

Lou

 

also, i noticed that the throttle body was larger then the oem... is this normal? it wasnt a tight fit... and would that one bolt the one further from you... i think it was the longer one... if that wasnt tightend, that could of caused the car to stall out?

let me know

 

i meant the bolt wasnt even in there.. cause it was self threading.... it wasnt able to grab down into the plenum.. cause it was going down at an angle instead of straight up n down

 

Yes, Crawford designed the new cast plenum with a slightly larger air inlet. All the Throttle Body Bolts should be snugged down to the proper torque value, and yes, if you don't it could cause a leak. Both top bolts need to thread themselves into the bottom plenum or the car wont run. And, as someone has already mentioned, the four bolts that Crawford supplies must be installed into the bottom plenum before installation of the New Crawford Top Plenum.

Lou

 

Loosen all the bolts around the perimeter of the plenum, this will give you the wiggle room to properly thread the center bolts. A little bit of a jiggle is all it needs.

 

exactly what happened to me...and that is what fixed the problem. you don't notice that the plenum is not flush because of that bracket....but you can hear it alright. i ended up calling dougy because that noise scared the crap out of me....but its all good now! you must also replace those 4 bolts inside the plenum or that will leak too btw...later

 

Damn this sux... Came accross this through a search. Crawford did not send me instructions and the whistle happened. I had to remove everything. I was wondering why Doug included the extra bolts. They are to plug the inside holes. Damn I wish I would have gotten instructions!!!! Oh, well at least this helped out.
Thanks

 

hugh? 100's of them have installed and everyone loves them. Of course, there are bound to be a few install errors and the like. But its certainly not a trend.

 

Yes, in my case it was install error. I forgot to plug up the holes left by the unused bolts. I should have checked their website and downloaded the instructions. I assumed Crawford would have sent instructions with the plenum...
Plenum is quite a bit louder than stock. I can see why Nissan built what they built. This is not for everyone...