exhaust issues

[Timoji]

hey everyone... i have been reading this board for a while now and am finally able to post something, most things have been covered in this world of wisdom but i seem to be having an issue i cant get answered by searching and am not sure about.

i own a vitara with a g16b engine but recently the exhaust has been sounding like its on its way out. there is a slight rattle when it hits around 3000rpm and only just tonight it seems to blow some darkish smoke. so i guess that means a tune is out. (not blue smoke)
what i was wanting to know is if the exhaust is on its way out would this be causing the smoke i am seeing?
thanks in advance.

[Gwagensteve]

It's not really possible to troubleshoot noises and smoke over the internet.

some pointers - A G 16 vitara will be getting pretty old, it might be time for an exhaust, (especially a new cat) and if the cat is fractured you'd be getting all sorts of noises from that.

As to the smoke, should be a separate issue, but I'd put a new 02 sensor in, good chance that might fix it. A faulty O2 sensor can lead to overfuelling (dark smoke) They don't last forever, normally not over 100,000km.

Anyone have any other ideas?

Steve.

[Hybrid]

Another thing could be the exhaust manifold gasket. Apparently, if its knackered, under certain engine conditions air can get sucked into the exhaust resulting in the Oxygen sensor registering lean and the ecu compensating by richening the mixture. Same thing can happen if the sensor itself is loose. Not very likely but it is one possibilty

[Gwagensteve]

Hmm - got me thinking- a loose sensor would also rattle.

They're normally insanely tight, but maybe, just maybe.....


Steve.

[MUD-PIGSIERRA]

Put oven mitt on and hand over the tail pipe get some one to listen for a leak along the zorst line....? If not the opposite way round and go under the 4by yourself but often on the older Vitaras the Cat falls apart and starts leaking which can make it sound pretty crap.

[Highway-Star]

x 1000 000 on the catalytic converter, mine fell to bits on me (in my Sierra) what an awful noise!

[Brendan-s]

Best bet would be to get someone to hold it at 3,000rpm while you crawl under and try and isolate the noise. I thought mine might have been a cracked baffle somewhere but turned out to be the shield between the cat and muffler.

[Timoji]

hi all. thanks for the replys, my flatmate and i had a look at it this morning and it sounds like there is either a hole in the exhaust near the engine or the gasket is gone in that area.
the cat is definately gone had a tap with a spanner and heard all the crap rattle around so im booking it in to get a new 2" pipe put through and possibly extractors. is it possible to run an exhaust without the cat?

now just to find the type of extractors i am after but i know there is a thread on this some where.
thanks again for all your replys.

[Hybrid]

is it possible to run an exhaust without the cat?

Technically, yes, but you can get defected for not having one installed. You know, global warming and all that hehe.

[joeblow]

if its an early type 1 engine remove the exhaust cover plate and have a look for a crack between no 3 and 4 pipes.they always crack.if so just replace the manofold with good set of headers.

[Timoji]

cheers for that joeblow if i get a bit of spare time i might have a look this arvo.

and yes hybrid i dont mind too much bout not having one as long as im able to put one in if i get caught but its not like it will be loud, id more so get pulled up on the sterio than the exhaust in this car.

and yes im doin my bit for global warming..... i vote for bikini's all year round

[MUD-PIGSIERRA]

i dont mind too much bout not having one as long as im able to put one in if i get caught but its not like it will be loud

Its not the main reason exhaust shops have to fit a cat to vehicles that left the factory with one when doing a replacement job (unless their dodgy) or (iF it was offroad use only) . But its your daily or weekend driver, getting caught without one I think also carries big fines down where you guys are....? Either way your going to end up needing a cat one way or another its easier just getting it done with a new zorst, and I would recommend going new extractors whilst your at it makes a world of difference.