Help locating my exhaust leak.

SON240sx Automotive
1

So my coupe has an exhaust leak. Somewhere from the exhaust mani to the cat. Not getting full acceleration, fuel consumption is through the roof. All expected.

Its getting a bit worse. Just used to “pop” gently while idling, now a bit more violently when I shift. lol. Probably due to the past track day.

How do I locate my leak? I know I can seafoam and see where the smoke is coming from. However, any other suggestions? Is this an “asap” fix because I can’t really get to the issue till this weekend.

If anyone wants to lend a hand it would be great!
(sorry for my newbness)

THX.

2

exhaust mani to turbo gasket? in the past track day, did ur downpipe bottom out/scraped the ground?

3

If you’re SR’d I put money on the manifold-turbo gasket, they fail alot.

4

Thanks Roel.

It did scrape a bit. I was assuming in general that the leak could be anywhere from the exhaust mani to the cat. lol.

5

get under the car when its cold and get some one to hit and hold the gas on a bit and run ur hand around the pipe feel for the exaust. anouther way is to look for fresh black exaust markings on the pipe

6

get someone to plug the tail pipe with rags and hold it while you look for the leak.

7

Thanks Guys. I’ll do that when I get home.

8

yeah it shouldnt be hard to locate a leak if u got the car raised up and just floored the throttle… thats how my boi found mine.

9

is it an aftermarket manifold or stock?

10

thx guys, havent checked it yet. seafoaming it tomorrow and then oilchange…

It’s a Megan manifold.

11

Easiest way is to plug the tail pipe as 87s15lt1 mentioned. The leak will get much louder and leak a lot more, it will be very obvious.

Even easier way is to assume it’s the manifold-turbo gasket because it always is.

12

^^lol nice. Thanks.

I’ll have it checked tomorrow an hopefully come to a conclusion. I’m assuming if it’s the gasket it can be easily sourced from a Nissan dealership?

13

megan manifold are known for there lack of strength, could have snapped a weld

14

yep, that gasket can be had at a nissan dealership, cross reference it to a 90-96 300zx twin turbo…turbo inlet gasket. i had to wait next day for mine.
or you can also go to varun, hes got them in stock.

15

if its a gasket fuck going to nissan. all i ever do is buy my parts from car quest. they are hand down the cheapest. and most reliable, they even will deliver to your door.

16

Found the sources after some seafoaming.

  1. Hole the size of a toonie on the downpipe before the flange towards the cat
  2. As Roel suspected, smoke was leaking from exhaust mani to turbo gasket.

Thanks for the help guys. I’m on my second 10 day permit. So I need these fixed and e-test passed within 10 days.

Anyone have an S13 Blktop 02 Sensor they want to sell?

Want to replace mine just to be on the safe side.