Hello all I keep getting vaccum leaks around the intake plenum which is causing my hunting idle, I used a brand gasket and some ultra black gasket sealer but for some reason I cannot get this to seal, I even took it back off and applied some more sealer but no luck, it any ideas?

 

Where is it leaking? does it keep moving around, or the leak starts in the same place every time?

generally you don't use any sealer on it. I've always used the OEM gaskets and they work just fine.

 

you sure you don't just have a vac hose leak somewhere?

 

Hey capedcadaver, I got the car running and spray a continous stream of MAF spray around the manifold and my idle improved so it's definitely a manifold leak.

 

o ok. always along the same place? mebbe a little piece of old gasket stayed stuck onto the LIM? same thing happens with head gaskets. i spent an hour buffing my friend's deck when we did his. an hour later... has bad rings so compression is 30psi short across all cylinders but at least the head is on good. so mebbe you should double-check to be sure there's no obstructions or anything on the mating surface.

 

The leak is always in the same place, in the rear of the manifold and the side near plugs 2,4,6.

 

246 is the front. 135 is the rear. didn't we talk about that in the other thread?

 

Yeah right notice I said in the rear of the manifold and the side near plugs 2,4,6 maybe I should have said the "area"

 

I do believe the plenum is warped, I was going to try 2 gaskets to see if this would work.

 

my bad. my eyes skipped 3 words. those being "and the side"

 

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Hey Cape, the plenum keeps leaking making my car surge in idle. I had taken it to someone who a put a straight edge on it and claims it's straight but it continues to leak. I've tried everything from one to three gaskets at one time and no luck. I was thinking about having a machine shop mill to ensure it's straight, any ideas?

 

for the cost of machining it i'd just try a used UIM from the jy..... are you sure none of the vac nipples are cracked or broken? did you check to see if the thing the UIM sits on is flat too?

 

I going to see if I could have both pieces milled from what I can see they are both siting flat. I've been messing with this for 3weeks now and I'm getting tired real quick.

 

i don't get why that part, of all parts of the car to get warped, would be warped..... yes it's aluminum but it doesn't get THAT hot... unless the car overheated and just warped everything.

 

Ok, new update I took the collector and the plenum to T-Hoff in Raleigh, NC to see if they could mill the collector #14013M and the lower collector #14013N (illustration below).
http://www.courtesyparts.com/betasit...1612_1623.html

They put a straight edge on both parts and didn't see any warpage and would have had a problem trying to bolt both down to mill them anyway. So at this point I went to Southern States Nissan and talked to a veteran mechanic name Gene. He looked at both parts and the only thing he could see was the fact that due to over tightening the bolt some thread was lifted. He believes that this may the cause of the issues I'm having with the gasket not seating and high recommended Permatex Anaerobic Gasket Maker Tube after using 400 grit sand paper to fix the thread issue. Cape I know your going to see this and I remember you telling me it took an hour to buff out your friends manifold so tell me what exactly did you use and how you did please, Sir.

Permatex Anaerobic Gasket Maker Tube:

http://www.amazon.com/gp/product/B000NV5OTS <Illustration).

 

nono what we were doing was a head gasket. we polished his block's deck for an hour with a felt pad and a diegrinder... you don't use RTV on a headgasket.

 

Ok Cape, thanks for the prompt reply.....LOL

 

now amillyon... have you been using the torque specs to tighten it? or just 'tight enough'?

 

Well......not really probably a little to tight and I know it's wrong!!!

 

torque specs are really important on these parts.....

 

Cape I just sent you a PM.

 

no offense dude... but I don't even have enough time to work on my own car... i know you're local but I can't hold your hand through everything.. anything you need to ask me, you can ask to the forum as a whole.

 

Hmmm, definitely wasn't expecting that response but understood. I'm not exactly your typical handing holding type of guy.

 

well i mean... i can't just call you when i'm at work. and i'm having dinner with a friend tonight. and I'm so low on money that ANY unnecessary driving is out of the question... sure as heck ain't going to Durham unless it's for work. So however i can help you online, I will. But there's others that can help you too on here.

not to mention i've never installed an intake plenum before....

 

Ok, group big question I'm hearing a loud pssssssssssssss sound coming from the intake manifold/injector area after getting another plenum/collector with new gaskets. I did put new injector seals and fuel rail spacers in after I inspected the injectors. The black spacers? Are they suppose be on top of the fuel rail or does the fuel rail sit on top of the spacers?

 

look between the throttle cable ends and you'll see the injector rail retention screw thing.

 

Hey, Cape the problem was that I had the fuel rail spacers on the bottom of the fuel rail causing the injector seals not to sit flush. I watched my seals jump up and down... as I revived the engine....LOL. I've chased this leak for a month and had the manifold off more than ten times with numerous gaskets etc. Now the car is running great after putting the spacers on top of the fuel rail!!

 

o ok... so the injectors weren't even down in their holes, so air was sucking in around them huh?

 

that sucks

 

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