i just got my plenum from crawford and tried to install it myself, needless to say i screwed up, and at first my car would start, and then just stall. then i realized that i didnt screw in the 4 bolts that came with the plenum into the lower plenum. so i went back and screwed those in, and reinstalled the plenum, now when i start my car it shoots up to 2500 rpm then hits 900 and starts to bog down, sometimes down to 200, then it shoots back up again to about 900 for like 15 seconds, then back down again. it never stalls, but obvioulsy this cant be good.

so i drove it enough to get to the infiniti dealer, so they could install my exhaust and cats and fix my plenum problem, well they installed my exhaust and cats for $580, but then wanted another 600 to fix the plenum problem which they said was caused by me tightening too tight and damaging the gasket. so i called Doug at crawford, and he told me to get it outta there and that it shouldnt be that much. later on that day i found what i thought was the source of the problem, which is a hissing at the rear of the plenum, and i put my fingers down there and could feel a good bit of air either being sucked in or pushed out. so i took it to a nissan dealer and just told them to reinstall this plenum "correctly". they got back to me today saying they need to just replace the gasket, and theyll do it for $200. good deal or no?


anyways, as stated above i thought that i had found out where the leak was coming from, but i call doug today, and he told me that "you cant feel a vacuum leak".

i know what im feeling with the air isnt normal, but if im not supposed to be able to feel it, is it actually the problem??

im just trying to brace myself for any possible bad thing the dealer could tell me is wrong with my car, when they call me after they install the gasket. is there anything else this idling problem could possibly be??

the car is an 05 coupe with 4000 miles, running perfectly fine till i took off the stock plenum and installed the crawford one.

help me please im stressing here.

 

You can feal a vacuum leak, you will feel air rushing past your hand when you put it next to it.

 

If it's really just the gasket, you can get a new one from PerformanceNissanParts for $5.95 or a 12 pack for $29.50. If I were you, I would just get a new gasket (even if it's from your local dealer, which shouldn't be more than $7) and try installing it again. $200 is way overkill. Note that I installed the Crawford Plenum myself and so far haven't had any problems. I took my time and made sure everything was hooked up correctly. I also read all the right threads to know not to over-torque anything.

 

what gasket are they talking about? Did you put your stock plenum back on? if you did, and you are still having problems, then take it to another dealer and ask whats up. The gasket (im assuming the upper plenum gasket its like $6) which can be found here http://performancenissanparts.com/ca...roducts_id=839. Not sure thats what they're talking about though..

 

damn, you beat me to it.. lol

 

well, im pretty frightened about even touching my car again after this plenum scare, im still worried i seriously messed up my car, even though everyones told me a gasket leak will cause no problems unless untreated for a while.

if the new gasket doesnt fix the problem, then ill just have to pay them another 200 to reinstall the oem plenum and that should definitely resolve the issue, then just talk to doug and ask for a refund for the plenum since there has to be something wrong with the plenum then right?

 

do yourself a big favor find a mechanic or a local place that will do this work for you! you are getting killed at the dealer! My mechanic would charge me like $50 for plenum install. He charged me $100 to install my 4 wheel brembo upgrade! Dealer wanted $500 and other places (performance shops )wanted $300.

 

Yeah, why do you feel that you need to take it to a dealer...they won't do a better job, just take it to a mechanic that you can trust or someone else you trust can vouch for.

 

in general yes you can hear/feel a leak.
The old school way to verify is spray some 'cold start' stuff (ether - but be careful - it is flamable) near the suspected leak... the engine will rev up and smooth out briefly while spaying the stuff.

 

A small vacuum leak will definitely cause rough/high idle, but it won't cause any damage, unless left like that for a long time and driven hard. What it does is cause unmetered air to enter the plenum and the ECM doesn't know how to compensate for it since it can't measure it. If it's just the plenum gasket, it's not a big deal. If it were the head gasket, now that would be a different story.

I would echo the advice of others and either get the gaskets and try it again yourself, or take it to a local mechanic and have him do it for much cheaper. $600, or even $200, to replace a gasket is absurd. They are just quoting you the Nissan book rate, even though it will only take them 1/4 of the quoted time to do it.

 

Best first investment you can make if you are going to work on your car is a good Torque wrench.

 

Take a good look at the gasket between the plenum and the throttle body.

My buddy let his slip when he put it together and it caused exactly what you are describing.

 

make sure to get a 5 lb torque wrench for the plenum install

 

why dont u put the stock one on and see if it still makes the weird idleing. Then u can take it to get professionally installed.

 

well, ive decided to just have them put the stock plenum back on for me.

it sucks cuz i just wasted $600. 395 for the plenum, and 200 to fix my mess up. so if anyone wants a brand new crawford cast plenum, pm me ill let it go for 300.

god i suck