I noticed the engines have a small whole under the front rotor exhaust port. I believe the factory gasket also has the whole.
I think I have an exhaust leak. There is a dark spot of oil residue, probably from 2cycle oil, seeping out between the gasket and my exhaust manifold.
Anybody else experiencing this? Any ideas of how to sort the issue? I was told a used factory gasket works really good, which is why I used my old one.
Any insight would be appreciated.

its a hole. its for the EGR system, and the S5 manifold, or JDM S4 manifold blocks the hole.

generally the stock exhaust manifold gasket is robust enough to reuse, to a point. sometimes they are bad and need to be replaced though

Im trying to hunt down this exhaust leak. I have been looking at all possible locations and for all possible signs. Usually you can find the exhaust leak pretty easy by looking for dark spots around exhaust parts. BY the sound of it; it sounds like its leaking between the turbo and engine. I say that because it has the distinct tick tick tick sound that speeds up with rpms.

It is pretty hard to get a good look around the large BW turbo, but i dont see any cracks on the exhaust manifold and i dont see any dark exhaust stain spots.(except the area already mentioned) I also dont see any dark spots around the the v-band for the wastegates.


DO you guys have any tricks to finding exhaust leaks? BEfore i tear everything apart to inspect?

check the manifold flange for warpage, if need be you can stack a metallic gasket like the Beck Arnley one over the stock asbestos one.

i also use permatex copper spray sealant to promote a good seal between the parts.

So that means that it was already warped. I would assume this couldnt just recently happened, specially when the car has only seen a hand full of 3 or 4th gear pulls. I shouldn't be seeing that much heat is what I'm implying.

Either way - I guess I'm tearing her apart tomorrow. I will get some copper spray to use when putting her back.

it really depends on the manifold and the torque applied, i have seen numerous manifolds warp as soon as they are torqued down. the only ones that seem to handle the heat and pressure is the cast manifolds.

Should torque to spec or maybe do less. Anything you want to recommend? I also remember the flanges being thick. Thicker than turbo flange.

I run an HKS Cast and I ran into this Problem and did just what Dr Revolvo(Ben..haha!) said.Run another gasket.It fixed it.
I got the engine out now so I am going to plane the manifold and put it a new gasket.

Just to be sure here.
Best route is to have it resurfaced, right?

If double gasket option is chosen how should gaskets be placed. Stock one on engine side. Beck and ... on manifold side? Also should I spray copper on both of them?

Sorry about getting so detailed, I'm trying to tighten up on these little issues.

I put the thin one on the engine side figuring that would be the part with the least amount of heat due to the coolant in the engine being able to cool that area.
The steel gasket is towards the manifold.

i actually do it the reverse way but it really doesn't matter that much. i choose to put the perforated gasket on the exhaust manifold because it has more compression and will seal better in non-uniform areas but both gaskets stacked should do the job equally.

resurfacing depends how badly the flange is warped if it is at all.

torquing has 2 options, factory torque which should not warp the flange but also has more of a chance of leaking if the manifold is warped even a small amount or crank the nuts down until they feel like almost snapping(about 60ft/lbs) which compresses everything enough to seal it properly. honestly i do the latter more often than the prior because these exhausts run extremely hot and the manifolds need good compression to seal well long term.

the largest issue is the quality of materials on the aftermarket manifolds, which varies greatly from one to the next.

OK that what I thought. Aftermarket gasket on manifold side and factory on engine side. Check.

Here is a picture of the original area is question.

First picture is upside down.
Also, the flanges are 1/2 thick but have rusted already so they should be a lesser grade of steel.

Waste gates might be the issue. Take a look.

i would do it all just to be safe but yes it does look like the wastegate flanges warped during welding.

i hesitate to say resurface the wastegate flanges because then the clamps won't have an even clamping surface on the V afterwards. you can try either tightening them down better, have them resurfaced and clamp them down very tight or just redo them over and more carefully. check to see which side is actually warped, the wastegates or the manifold side, likely it is the manifold side.

your best bet would probably be to just drop off the manifold to a machine shop and tell them to true up all the mating surfaces and then do all of the above before this post. if it still leaks afterwards weld on new v-bands.

also keep in mind with the amount of leakage that appears to have been going on it is likely your turbo will respond quicker and boost will rise to a small degree, compensate for that with your boost controller before doing any hard runs and set it to where it was tuned to after dropping the numbers down. the tune should still be equal to what it was before, assuming the beginning of spool maps are tuned well enough.

Well... manifold is also leaking. Between the gasket and manifold flange is where is dark spot. Notice engine side of gasket is shiny(lil oily) but the front rotor lower part of gasket is dark spot. So is the lower front rotor area of the manifold is dark. Also took pictures of the waste gate vband flanges on the manifold. Any suggestions?

I will drop off to a local fabricator that is very reputable. (Stage 6 Motorsports)
Ben I do not run boost controller,but the reason why I'm fixing all this is because I planned on tuning next week. I will take all precautions to not hurt this engine. Im out to proove people wrong about rotaries here in north east florida, plus Im really hoping to get A LOT of wheel time out of this engine. I'll get remote tuned by kan ,again, as soon as everything is fixed on the manifold. I will see what Dwight(stage6) suggests for the vbands. I'm not so worried about the manifold flange as it seems like the easier fix.

I used a local engine machine shop and they charged me 73$, which is more than I expected. They said that is was warped but now she is resurfaced and looking good. I don't plan on fixing the wastegates as they seemed pretty loose at the vband clamp when removed. I will just have to deal with that,for now,by making sure the vbands are tight. I should have everything reinstalled by this weekend. And tuned by the next one. Looking to tune to 8k rpms this time. Let's see where the stock ports stop making power with bw s360.

I'm so bummed. Manifold resurfaced, doubled up on gaskets ,and used copper spray.
The exhaust leak sounds worse than it did before.
It sucks cause there is no way to pin point it. :/
It still sounds like its at the header though with the ticking sound.

Slight dis coloring is normal on the vband flanges. The inner fire ring is what seals the vband flange on the wastegates, not the flanges to each other. You would have to make a thicker flange, and the machine after welding to cure this completely. Just put your hand near all the possible spots when the engine is dead cold, you will only have about 60 seconds, but if you have a leak you will be able to feel it. You shouldn't need two gaskets, I've never done that and all car we build are exhaust leak free.

Well I'm going to tear her apart next weekend- again.
Turblown, what is your gasket of choice?
What do you guys think about copper gaskets.

A properly surfaced manifold shouldnt leak. Make sure youve got everything torqued down tight. Double gasket if needed. Ive used mls gaskets on everything ive ever put together and only had to double gasket one manifold.

Did need use a torque wrench but I made sure they were very tight.
Which brand MLS gasket are you using?

Ive always used felpro or oem

i use a stethescope normally to find leaks, except i remove the end off the tube and use just the tube for noise pickup.

knowing exactly where it is originating from will make fixing it slightly easier.

I'll be hunting down a stethoscope at parts store. Hopefully I can pin point this leak.

I've been searching copper gaskets and found this. 24$ is a good price, but can it hold up? Its .043 thick. http://scegaskets.com/product/sce-ga...t-number-9422/