Kurtomac

iTrader: (5)

i picked up a 98z yesterday and when it was under load i heard a ticking, so i popped the hood and on the drivers side i could hear the air puffing out of somewhere so i looked for black on the head figuring it was at the manifold but didnt seen any so either its leaking on the bottom side of the manifold or somwhere near by, anybody else have an exhaust leak on a stock car....and yes im sure its exhaust not internal or valvtrain

RPM WS6

iTrader: (3)

Could it be that the AIR valve on that side has gone bad, and the ticking you're hearing is that valve fluttering? This would be a more likely issue that the factory manifold gasket failing, honestly I've never heard of a stock LS1 manifold gasket leaking before.....

Kurtomac

iTrader: (5)

yea ive never seen a stock MLS gasket leak either, so explain further where that valve is cuz it sounds like its right near the manifold

RPM WS6

iTrader: (3)

Start by tracing the AIR tube coming off the forward part of the manifold (it runs directly above the manifold), follow the tube back to about the area of plug #5, and look directly above that plug. You will see a black metal bulge that couples the silver metal AIR tube coming off the manifold and the rubber line behind it that runs eventually to the AIR pump. That black bulge is the check valve. I've never had to replace one, but I've heard of others having them go bad and cause a ticking/exhaust leak noise (more common on cars with headers, but it has happened on stock manifolds as well). From what I hear it's a pretty cheap part to replace; worth a try before doing all the work to change the manifold gasket.

Hope that helps.

Kurtomac

iTrader: (5)

RPM you are the man, hit the nail on the head,it has a small hole in the bottom of it, i got one of those laying around from my 02 but its friggin stuck, im gonna WD 40 the hell outta it earlier and try and swap them out

ArcticZ28

iTrader: (14)

hmmm, maybe i should check that too... i've been hearing a ticking for a while as well but just figured it was my mac shorty gasket leaking. If it is the AIR valve that's bad, would it cause ticking loud enough for me to hear inside my car under slow to medium acceleration?

Kurtomac

iTrader: (5)

thats only when i heard it

ArcticZ28

iTrader: (14)

interesting... i never would have thought of that... all this time i just figured it was an exhaust leak. I'm curious though, anyone know how much that AIR valve runs?

RPM WS6

iTrader: (3)

Glad I could help.

RPM WS6

iTrader: (3)

As you have headers (I'm assuming you do, you mentioned Mac above?), the chances are very high that check valve fluttering is the noise you are hearing. There is a restrictor plate mod that many with headers have done to fix this issue.

It's fairly simple to do. You can make the plate using an AIR gasket as the template, then cut out a piece of metal the same size & shape. Drill holes on the edges for the bolts (matching the gasket, 5/16" I think), then drill one 3/16" hole in the middle of the plate. This will allow enough air to pass for the system to work, but dampen the pulse enough to keep the vavles from being damaged. If you are already hearing the noise, you'll want to get some new check valves at the same time as you make this plate.

I had the restrictor plate mod on my WS6 with Bassani headers and it worked great, no flutter/ticking. You can probably find some pics of this mod if you do a search.

Hope that helps.

ArcticZ28

iTrader: (14)

Excellent, I'll try that. Thanks a lot RPM. Any idea on how much a new AIR valve is gonna run me by chance?

ddelallata

iTrader: (2)

Why don't you guys do away with the AIR systmem all together? That's what I did.

TheBlurLS1

iTrader: (8)

hell yes get rid of that AIR! also get rid of the EGR if you have it. you can go to a local speed shop w/ ls1edit (or hp tuners) and have them delete all the emmissions stuff for WAY less than the price of a full tune. AIR only helps with emissions AT STARTUP, after the cats are warm, it turns off and is useless. cut out some block off plates for the exhaust, buy a 1 3/8" adjustable freeze plug, for EGR hole in the intake manifold, and tape up all the wires.

MTI deleted all of my stuff and rear O2's for 75 bux. this cleaned up the underside of the hood, less rattles, less things to break, less weight etc. plus it would have cost more than 75 bux just to buy O2 sims!

ArcticZ28

iTrader: (14)

Don't you need AIR to pass emissions? Or is that just EGR? Clearly I have no idea which is why I haven't done away with either of them cuz of such strict emissions around here.

RPM WS6

iTrader: (3)

No problem.

Sorry but I have no clue on the price. I never had to change mine, but I've heard from others' that it's not expensive at all.

As for removing AIR and/or EGR, it all depends on what sort of E-testing you have to pass. If you have a visual inspection, and they are strict & know what to look for, you may fail due to the missing equpitment. However, if all you have is an OBD scan test (as we do in IL for '96 and up cars), then so long as you get proper tuning for the removed items you will pass the scan.

Hope that helps.

Kurtomac

iTrader: (5)

got around to putting my stock check vavle off my 2002 on there, that old one was fockin on there nothing a lil WD40 didnt take care of, quiet and smooth as can be now, the old one had a small hole in the bottom of it