2012 Jimny exhaust problem.

My Jimny's engine sounds a bit loud at cold start, and then goes a bit quiet as it idles. It kind of sounds like I'm hearing the combustion or gasses leaving the cylinder, a faint tractor- like sound. Also, after switching off the engine, I heard a hissing sound somewhere around the area of the exhaust manifold and pipe going in under the Jimny, also a faint sound that gradually went quiet. I noticed the catalytic converter flange is leaking slightly, black residue around the flange (flange on the side of the catalyst where gasses go in, i.e. from engine.). Also, while the engine runs, I can smell exhaust fumes at the exhaust manifold, I know it is normal-ish, but this smells a bit too excessive.

Hope someone could help/ guide me with this if it's normal or not. It is my first Jimny so please bear with me.

Thanks in advance,
Stefan

Hi Stefan,
it does not sound normal if I compare it to my 2009 which has none of your mentioned issues. The exhaust leak is not correct, but I am unsure as to why you get a hissing sound when you turn the engine off. Is it possible the exhaust is blocked at the CAT and the leak is the engine trying to breathe?
Is your engine performance ok, is revs well and pulls in all gears?
Maybe wait for a few more comments before you do anything.
Mike

Hi Mike,
Okay so it could be a problem I need to look into. The hissing sound is like a blowing sound, like air escaping under pressure. It could be possible that the CAT is blocked, but wouldn't a warning light be displayed? Once the engine stops turning I can hear it clearly. Gasses do come out at the exhaust though.
It handles pretty well, I mean I don't rightly know how a Jimny should perform. It is a 1.3l so that's why I get to 60km/h in 5th gear I'm guessing. It idles at about 900 revs, although, cold start it runs around 1100 revs, but that's the auto choke right?

Thank you.

You dont normally get an engine warning light if the CAT is blocked, but engine performance suffers. Top speed is reduced or the engine will not rev out.
You say 60Km/h in 5th, is that as fast as it will go?
To put into context in 5th on the flat motorway it should achieve 70mph without any issiues, which is 112kph. It should sit all day at 60mph (96kph). I tow my caravan faster than 60kph, so if thats a max then yes something is blocked or wrong.

edit - yes auto choke, at start up any rpm from about 1500 down to the normal 800-900 when warm.

 

I would second it sounding like the catalytic converter is on it's way out.

Oh, that's problematic. I thought CATs are designed to have a life as same as the vehicle. I change gears at slightly over 2000 rpm. So I go to 60kmh in 5th, but it does go to about 100-110 if I push it. To put it simply, it takes long to get up to speed when entering the motorway. It kind of feels like it struggles to accelerate, but I'm new to a Jimny, and I don't know how I 'should' drive a petrol engine, been driving diesel too much.