4.2 Turbo Diesel 'hissing' noise when accelerating

[rynskiii]

How's it going. I understand this may have been covered previously so apologies...

My 4.2 Turbo Diesel 100 series is making a hissing noise under moderate to heavy acceleration, notably when the turbo is kicking in going up hills etc, so basically when the engine needs more power. I'm thinking that maybe this could be a leak somewhere in a hose or a gasket maybe even a blowing exhaust? It's a little hard to pin point because revving from idle doesn't create the noise. It also seems that the louder the hissing the less amount of power is available.

Wondering if anyone has had similar issues before and might know where first to look? Cheers.

 

[uHu]

Could be a blocked particulate filter. It will hiss as you push more through it. That pressure build-up can also cause a Turbo Pressure fault code.

 

[rynskiii]

Cheers for the reply. Haven't actually thought of that. It does do decent motorway miles every week so I thought it may maintain natural burn off...

 

[AndycruiserguyLomas]

Mine started to do the same a few years ago, under load you could hear the turbo whine. It was a build up of pressure forcing the sprung joint apart .

 

[rynskiii]

Thanks. I've just been having a look around the truck. I can see soot collecting at the joint between the front exhaust pipe and the manifold where it is connected by them spring bolts - is that where you mean? Could something like a blocked cat for example be causing that back pressure build up if that's where the issue is?

 

[Mungrol]

Hey Rynskiii,

Did you ever get resolution on this?
My 1HZ that is turboed recently started doing exactly what you are describing here. Trying to figure out what it could be.

 

[uHu]

Cheers for the reply. Haven't actually thought of that. It does do decent motorway miles every week so I thought it may maintain natural burn off...

Doesn't actually burn off. It's a filter, not a cat, although it looks a bit like a cat on a petrol engine. Motorway miles make less soot, but still it builds up over time. Farting at the spring-bolt joint can be either misaligned pipes, bad springs or seal, or a heightened pressure because of blocked exhaust (particulate filter).

 

[CRUISER KING]

cut the cat open (gut it) then weld it back up and you will have full power and it will never hiss again (end of)
(only the undisputed cruiser king knows these things !!
kind regards from the king himself!!