Exhaust blockage/restriction???

[Copafield]

Trying to diagnose a problem with our car. Symptoms were occasional loss of power under load while warm, now the car simply has almost no power under load and there is a strange noise coming from the air intake. I can rev freely while in neutral but under load i can't really get above 40k/h, i can slowly rev out to this in 1st but any other gear you go nowhere. Would I be able to rev this way (while in neutral) with a partially blocked exhaust and then not under load if the exhaust was restricted? Don't really want to pull the exhaust off the car if I don't have to.

While chasing down the source of the sound tonight I took off the air intake system right down to the butterfly and the noise is still there when revving. It's best described as a type of growl.

2004 Suzuki Liana 1.8L M18A Engine 225K meters on the speedo.

Any and all help appreciated!

 

[footprints]

Long time since I tinkered with cars, but as it was worse when hot have you checked around the head gasket for any sign of leakage, any sign of water/mayonnaise in the oil, or contamination in the water?

Worth also listening around the inlet manifold with a bit of hose pipe as a stethascope you might hear an air leak.

Sorry thats all I've got

 

[CylonRaider]

Is it TurboCharged ?

Sounds like the pipe to the Charge/Intercooler has come adrift/sprung a leak

 

[Copafield]

Thanks for the replies so far. It's NASP so no, no turbo/piping to come off (i've had turbo's in the past and this is a similar feeling but worse than a pipe coming off).

The sound i'm hearing is definately coming from the 'butterfly' - before i removed the box and pipe the sound was coming from the side of the engine - now it's coming from the rear. I was going to use the hose trick had that of not made a difference.

There doesn't appear to be a head gasket leak, at least not internally anyway. Oil is normal, coolant is not going down and there's no oil leaks (that i noticed, it was dark).

 

[Burnerman]

Take the lambda sensor out from the engine exhaust downpipe, and see if performance returns......maybe the catalytic converter has called it a day.
John

 

[Copafield]

OK, pulled the O2 sensor out, took it for a quick drive (7:30pm - sure the neighbours love me hah) and i was able to get up to 70 no worries, definately not at full power but far more than it had when the major problem occured - so - unless somebody says otherwise i'm going to put the car on the ramps tomorrow and pull the exhaust off from the cat back, put the front end back together and then see how she goes (might do this trip during the day! hah). Will keep everybody informed of the progress

 

[Avocet]

It does, indeed sound like a collapsed or melted cat brick, partially blocking the exhaust. I think the odd intake sound you were getting was just because you're not used to hearing the induction noise when the throttle is much further open than normal for a given engine output.

 

[Copafield]

Just to add to the bank of information ... this problem was indeed a collapsed cat. First cat is shredded and and lot of it ended up againt the 2nd cat and there's some still suck between the manifold and 2nd cat, just after the elbow. There's a type of exhaust gasket made out of woven steel/metal/alum/whatever but it's looped around a big chunk and they can't make it through the next bend. (have taken everything off including the manifold).

Manifold + cat housing is in the boot of the car and it's off to the exhaust place tomorrow so they can weld in a new one CAN'T WAIT to see how the car goes after this, god knows how long this has been happening