Rough Idle And Ticking Noise From Exhuast Manifold Side

[Kryostaisis]

as topic states, i have rough idle, it reves up between 300rpm and 1200rpm up and down, up and down, and eventually it gets back to normal. its been happening for the few days.. i will try cleaning the AFM and throttle tomorrow...

but i also noticed a ticking noise from the exhaust manifold, i think it started out as a whistling sign and then in the last few days, its been ticking everytime i rev it anywhere above 1000rpm. ive been told it was a leak on the manifold that makes the ticking noise, but i dont have any ideas

the car is also "boost spiking" in a sense that after 4000rpm, there is a flatspot till 5500rpm, at the same time, boost will creep up from .7bar to .9bar and drop back off at 6000rpm to .7 again

anyone have any ideas?

Edited April 22, 2006 by Kryostaisis

[No one]

sounds like its leaking or loose

might be good to replace the gasket and tighten it up

[nfi]

You can be comfortable your exhaust gasket is gone. That can also cause the sporatic boost control. Don't leave it too long as it can burn an exhaust valve by giving it a hard time for a long period of time with the exhaust gasket leaking.

The idle is not generally effected as bad as you seem to suggest it is though when the exhaust gasket is gone. Sounds like a vacuum problem to me in combination with the exhaust gasket. Do one thing at a time though and get the gasket repaired.

[Kryostaisis]

thanks for the advice, yeah im thinking its a combination of things, but not sure what they are, i will pull apart the manifold and check out the gasket and get back to you guys

regards

[R31Nismoid]

manifold gasket

common problem... just be careful with the studs

[Kryostaisis]

anyone got any idea on how much manifod gastkets cost? should i use gasket glue aswell as a new gasket? or can i just use the gasket glue on the one i have now?

[SKY 34]

I read sumwhere that a ticking noise means knocking....prolly sumthing causes your engine to burn really lean..esp with boost control problem you are having...need to verify this tho..I'm not very sure

[R31Nismoid]

ticking is not knocking/detonation

[Kryostaisis]

nah the ticking is a leak, im pretty sure about that, although ive been told that my flatspot/power loss problem might be due to my knock sensor being damaged and so it may be retarding the timing... but im not sure if thats the case, im going to fix the leak first and see how i go from there

Edited April 14, 2006 by Kryostaisis

[Blitz]

You have an exhaust leak - Get your manifold off and replace the broken gaskets

I'd grab the Tomei metal exhaust side gasket set, but you could use factory type gaskets if you preferred.

[Lazy-Bastard]

anyone got any idea on how much manifod gastkets cost? should i use gasket glue aswell as a new gasket? or can i just use the gasket glue on the one i have now?

OEM exhaust gasket is about $85

edit: hmmm.....that might have been at trade price, so say ~$100

Edited April 15, 2006 by Lazy-Bastard

[Kryostaisis]

any other ideas? im pulling out the manifold tomorrow and hopefully have it back up and runnin by wednesday

[Chris Wilson]

any other ideas? im pulling out the manifold tomorrow and hopefully have it back up and runnin by wednesday

My bet is you will find one or more head to manifold studs broken, or the threads pulled out of the head. Probably broken ones though. Drill the manifold holes bigger, so the manifold can expand lengthwise without putting a shear load on the new studs. To get the broken bits out centre drill them (I made a guide plate to bolt on the good studs and a collet in a hole centred on the broken stud, to centre the drill bit automatically). Drill to a size less then the ID of the thread root, and to a size where you can tap in a splined (Torx) bit, with enough purchase to allow you unscrew the broken piece of stud. Buy genuine ones, don't use bits of sawn off set screws!!

[Kryostaisis]

ok, ive started to pull off the manifold, i have still left the turbo hanging off teh manifold, was kind of hoping i wouldnt need to remove it, but i guess i have to now that i cant get to the other nuts.

just one quick question, i can notice there are dark spots around the manifold, which suggests that there is a leak, at the front end of the manifold(nearest to the headlights) there is a leak, but i think its due to the bolt being very loosely put on, as i could undo it with my fingers.

at the back of the manifold, there is a really dark patch of carbon deposit, and the noise did seem to be comming from the bck...

my question is, is there supposed to be 12 nuts and studs altogether for the manifold?

if so, i think my last stud and nut closest to the firewall has snapped off, god knows how, but how am i supposed to get a new stud? where can you get them from?

ill keep everyone posted.. hopefully this will solve my flatspot problem

Edited April 17, 2006 by Kryostaisis

[predator]

there's 12..

they're $2.85 each from nissan.

Its usually the front and the back ones that snap off, yup.

i'd be spending the extra effort taking the turbo off, it will save you time and make it much easier to do what you need to do.

[mic087]

yeah i had the same problem....was the gasket.... my advice is WD40 the bolts b4 undoing them...otherwise u r likely 2 snap a few and that gets F$#%ING annoying....

[Kryostaisis]

ive taken most of them off, ordered a few new studs, 2.25 each, but the gasket is 130bucks!!

then only problem i have is that the stud closest to the firewall has been snapped (most likely for quite some time now, as ive been experiencing the boost creep and flatspot for quite some time now), i have no idea how im going to get a drill into that to undo it, anyone have any ideas?

[heslo]

Sorry to butt in here, but could you possibly take some pics of your progress so I can see how to go about doing this as I suspect I might have the same problem.

Thanks

[Kryostaisis]

no worries, but ive already started, ill take photos from now onwards

[heslo]

Cheers bud, just so I get a rough idea, thats all, might even help out some others here thinking of doing the same