Hissing noise audible when TD4 engine is running - Any Ideas??

I had a complete clutch change one week ago on my TD4.

Master, Slave and clutch plate etc.

There was no hissing sound before I took the vehicle into the garage, that's how I noticed the noise after the work had been done.

The night I brought back the vehicle after the work I noticed a 'hissing noise' audible whilst the engine was running, as though 'air' was leaking or similar.

The sound is from the front lower area of the engine (looking forward at the engine)

There doesn't seem to be any fluid leaks of any kind.

The performance doesn't seem to be affected, or at least I don't think it is.

Does anyone know what the noise could be?

Could the mechanics have damaged something whilst dismantling the engine to get to the clutch area?? :doh:

Thanks in advance

Turbo hose starting to split - top right front of engine (if you look from the front of the car), it is the large pipe with a 90 degree bend.

mine started to whistle for a while then got really bad and split (plus lots of black smoke).

Turns out it was the vacuum pipe that runs to the EGR valve, the end of the rubber pipe was not making a tight seal.

Cut end off, and reconnected - hissing noise now gone.

tsam19 said:

Turns out it was the vacuum pipe that runs to the EGR valve, the end of the rubber pipe was not making a tight seal.

Cut end off, and reconnected - hissing noise now gone.

Click to expand...

You should read the sticky about blanking it off mate. I done mine, a bit more torque for towing, supposedly better MPG, but can't confirm that yet.
Easy job to do, took me about 1minute.

Right so the EGR valve can be blanked off on the TD4?

Will it cause any damage?

I presume the EGR valve on any vehicle does the same job, just allows a percentage of the exhaust fumes to recirculate back into the inlet manifold isn't it?

Which really, this method of allowing 'hot' exhaust to mix with 'cold' air chokes or suffocates the engine, causing lack of power.

I did it on my BMW, had to put a 2p coin in between the EGR valve inlet orifice and the connecting steel pipe from the exhaust branch off pipe then tightened everything back up.

I noticed the difference straight away, probably be the same on the TD4 too.

Any links to the sticky on doing this quick job?

Any pics on how to do it?

Cheers for the info.

markyzs180 said:

here u go...click on this link to take you to the post with the picture on of where you need to blank it off with the peg and pipe kit

http://www.landyzone.co.uk/lz/1288169-post198.html

Click to expand...

There you go mate.
As for any damage, I very much doubt it, if anything, stopping the **** from the exhaust has to be a good thing, right????

Just had this so watch out for it.

Re: angeloc

I had the same happen too, been replaced now though.

Re: mick 1986

Cheers, I will give it a go.

Just checked the pics and they don't make any sense, what will I be doing to blank off the egr valve??

tsam19 said:

Re: angeloc

I had the same happen too, been replaced now though.

Re: mick 1986

Cheers, I will give it a go.

Just checked the pics and they don't make any sense, what will I be doing to blank off the egr valve??

Click to expand...

Neither photo shows the EGR valve on a TD4

angeloc said:

Neither photo shows the EGR valve on a TD4

Click to expand...

Very true, but if you bothered your arse to read the thread, you would have found that your only blanking the vacuum pipe on the EGR valve, the one that actually controls the EGR!
But hey ho, can't ask for miracles eh?

EGR = Exhaust Gunge Recepticle, only there to keep the Green Party happy, but you're in a fourby, so **** 'em and fit a blanking pipe.

My EGR bypass before fitting a new hose

Afternoon guys, the initial description matches the 'hissing' my td4 is doing...
Mine too has just had a full clutch re-fit and the hiss is louder the fast she goes.
went back to the garage and they told me it's the particle filter.
Am i mistaken, I thought the particle filters are fitter to newer diesels.
Mine's a '54 HSE
Glad I checked here and will certainly check out the EGR fittings, as found a thread indicating low A/C, but this seems more lightly.
Mike

dunt think td4 had a particle filter fitted at any time

usually caused by split intercooler hose, esp. long one across front of engine where it rubs on fixing screw. when you replace the hose, split a bit of the old one to wrap round the new one where it rubs.

I took mine back to the garage due to hiss noise audible after my clutch change- turned out to be one of the small diameter vacuum hoses at the rear of the engine on the right hand side not connected properly - very simple fix.

Put your ear to the engine and you should be able to trace it yourself.

If not take it back let the garage sort it!