i have a 2004 rx8 with over 60k miles and the greddy turbo kit

after one day of lots and lots of high rpm driving and heat my 8 started to rumble and sputter. it had no power wat so ever and it felt like it wanted to die. it was real hard on starting after that.
we immediately checked everything that we could think of

we thought it was a vacuum hose but after further investigation we found nothing
after over a month of nothing we decided to order a new intake manifold from pettit racing to replace the stock plastic one (im still confused on y it is plastic in the first place)

if anyone else has had this problem and kno a solution plz help

 

just fine..i use valvoline

 

What specifically did you check?
What EMS are you running. What is your AFR when this happens?
Are you running with cat or catless?

 

i have the complete stock exhaust

we checked all the vacuum hoses to see if they broke or slipped off, spark plugs, then we went to the manifold

im not as informed on cars as you apparently. wen i say we i meant me and my mechanic so i dnt kno wat u mean wen u say EMS or AFR

 

i had the same problem....there putting a new engine in mine.

 

You haven't checked anything relevant, yet.
Compression check (with a proper rotary compression checking device), idle vacuum check and spark check (with a timing light) are the absolute first order.

 

I am not being critical. Just need info to try and help.
AFR - Air Fuel Ratio. Do you have a gauge that reads it?
EMS - Engine Management System.

You might want to consult with your mechanic on the above items.

Also, if you have stock exhaust, most likely an intensive high RPM day fried your cat.

it is quite common on turboed cars.
The quickest way to test if it is in fact that, is to bang real hard on your cat. If you hear rattle coming from it, then you don't have much to worry about. Either have your mechanic take it our and gut it, or replace it, or put in a mid pipe.

 

my ems is the greddy emanage ultimate

i dnt have an air fuel ratio gauge but my mech did reccomend it

also..and im rly sry...i forgot to mention that you could hear a sort of vacuum sound coming fron the upper manifold area

 

You still did.t tell me anything.
damage to the manifold is something I haven't heard before. Has anyone?
Before you get to testing the extremes, make sure all the simple stuff is taken care of. Make sure all your hoses are connected to the intake pipe.
the sound may be coming from the OMP hose. It sucks in a lot of air when the engine is running making loud whistling noise. You don't hear it when it is connected into the intake, but if it is left loose in the hood (must be filtered by a breather or something in this case) it will make loud hissing noise. it is no big deal though.

Did you test your cat for rattles? Also check your coils and spark plugs, test the compression.
If the cat is rattling, have your mechanic take it down, and drive a steel rod through it to clear out the remains of the catalytic and shake it out (wear a mask dont's breathe in that stuff). Then reinstall it and see if that improves things.

 

first and foremost i want you thank you and anyone else for replying to this thread

ok my mechanic has been working with pettit racing (over the phone of course) once my mech told the guys there the deal with my car....completely stock except for the greddy turbo kit...stock exhaust stock plastic intake manifold....he said that the plastic manifold could easily be the culprit. your cat idea could very well be the problem but tht doesnt explain the sound coming from under the hood. if you heard it yourself you would say the same thing that the sound was coming frm the intake manifold area, more specifically around the oil cap..
and my mechanic looked for any problems with and loose hoses or anything like that and he said tht he didnt find anything wrong like tht...?

 

It takes a LOT of pressure to crack that manifold.
The only one I've heard of breaking it was HKS, and I suspect it was resonance from the blower assembly that did it, not pressure.
There are plenty of turbocharged cars with plastic intake manifolds.

 

Did he do the check?
You symptoms sound exactly as what I had experienced when my cat went.
the car stopped making power, and wanted to die. if you had an EGT you'd possibly be seeing very high temperatures when cruising and your AF ratios would be going high wire.

Check the cat. It will not cost you much (compare to a new manifold) and may well solve the problem.

Sound from under the hood can be the result of a punctured coupler. It's not a secret stock Greddy couplers are cheap crap, and people had them break and loose boost, or it will suck in the air under vac thus making the noise...

Unless your manifold had some sort of damage originally there is a very slim chance it would have cracked from the boost that Greddy makes.

 

That would take crazy pressure, too.
The UIM/LIM joint is bolted and pinned and the flange is not under stress.

 

In any case, even with the crack in the manifold, I'd just epoxy it.

 

I would do a compression test first after checking all the vacuum lines like you already did.

Also check the cat like rotorocks said. If it's fried it's inhibiting exhaust flow and could be the culprit.

 

No.
One of the first tests I did when I was first preparing for FI was to bolt a piece of sheet across the exhaust outlets, put a storm cap on the TB and pump the intake up with pressure. I wanted to find leaks.
I put almost 80 PSI into the system.

 

I'm just talking about the "O" rings. I'm not sure what you are alluding to.
I've had a half dozen manifolds go through my hands over the last few years and the design hasn't changed.
An o-ring won't leave this manifold unless it is installed incorrectly.

 

Sure, but why would the UIM come off in the GReddy install?

 

well maybe the mech wanted to see what's underneath?

he he he

 

True. Vacuum/boost leaks are impossible to properly diagnose from a distance.

 

MM, the babes are all dressed!
WTF?

 

Dressed, but wet. I have the after pics as well, but I can't post them here...

 

I would do a compression test first. If that pass, I would check for a clogged catalytic by removing it and start the car. If that doesn't work, then intake manifold.

BTW MM, you can PM the after pics

 

ok the verdict is in!

turns out tht the problem was in fact the intake manifold
with the new manifold from pettit racing it runs great

thx to all who offered a word of help

 

it sounds like you're running stock emu tune.

*sigh* .....