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My 406 HDi sounds to be struggling at higher speeds or higher revs (I know its a Diesel but the wagon doesnt sound as bad or struggled)

Basically, the engine note changes after 3500 to harsher sound and really struggles to pull and just seems out of breath.

Its been servuice, new oil filter, new oil, new air filter, new fuel filter etc.

Some people may have also read I have a hissing noise aswell on acceleration above 1400-1500 rpm.

Could it be a blocked catalyst?

When the HDi goes all clattery and nasty it means the fuelling's out. Mine only did it once and sounded like the bottom end had gone.....100 yards down the road it cut out, dead, it was the crank sensor not knowing what was going on. It never did happen again

Don't know what to say on yours really but the exhaust should give a big blast against your hand with a 3000+ blip of the gas.

Welly wrote:When the HDi goes all clattery and nasty it means the fuelling's out. Mine only did it once and sounded like the bottom end had gone.....100 yards down the road it cut out, dead, it was the crank sensor not knowing what was going on. It never did happen again

Don't know what to say on yours really but the exhaust should give a big blast against your hand with a 3000+ blip of the gas.

It wasnt clattery, the engine just made different noise as if something wasnt right. I know diesels dont particulary like to rev but mine seems a lot worse than the wagon which seems to love to rev freely to 3500-4000 when needed (Yes I know peak torque is down by 2000 and hp @ 4k) but you know, sometimes to give it a blast

I remember you saying feeling the exhaust pressure, I should check this. mine does pull well between 1500-2500 though, but then it really tails off

Actually, finking about it, Intercooled Diesels don't really like these cold temperatures in fact the over-cooling of the charge air quenches the burn in the cylinders leading to a loss of performance and more smoke (incomplete combustion). Apparently an air-entering temperature of 15 deg C is the best

Maybe your engine's running cool (thermostat) ??

Thermostats are under £10 usually so maybe I should do it anyway?

And as per another topic the wagon does heat up quicker (Im never buying the same car as comparing is inevitiable lol)

The little fan in the head liner near the light does spin now and its a lot better

Welly wrote: Intercooled Diesels

Bruce has two HDi 90's.....do try to pay attention.

Don't think it will be the cat - I've had that on a HDi 90 Xsara. Symptoms are increased turbo lag, lack of 'throttle response', but ultimately virtually as much 'go' as a healthy car with no change in sound.

Fuelling would be my guess, as Welly suggested first.

Hmmm.

Maybe try some Forte/wynn injector cleaning directly into the fuel filter housing then?

Dying High pressure pump...?

Possible, but I've not heard of one failing.

Sounds like you might be best getting a diagnostic check done, (much as I loathe suggesting giving the steallers any money), but that would at least let you check the HP pump pressure.....

The crank sensors do fail ocasionally - I've no idea how hard they are to change, but as you have two cars it's a thought..

Sorry Doggy, I goofed up, but the principle's the same - i.e a cold engine. I'd be looking at the stat first I think.

Hi there , I'm not sure if i have the same problem as yours?

But am equally as puzzled and in hope of an answer.

I also have a noise that starts at 3000prm, more noticeable under load, and the power is not really as much as it should be.
It sounds a bit like a tappet noise, maybe little end or piston slap kind of sound, definitely not big end or mains, but I have a feeling that it could just be a pinking kind of symptom associated with a fueling problem of some kind like has been suggested.

My 406 has the 2.2 Hdi, and has done 68k. The sound has been there since i bought it at 65k.

Now, my beloved old 406 2.2 Hdi had the same noise when I bought it at 132k, so when i asked my helpful, Hdi knowledgeable MOT guy to take it for a spin, and he returned with ideas of little end or piston slap, and just said treat it with care, put it down to a hard life and recommended that i did a quality oil change, which subsequently did not help the noise.

The thing is, a few thousand miles after the oil change, the noise just disappeared one day, never to be hard again !

It seemed a long time from the oil change for the possibility of a mechanical wear noise that had been helped by quality oil..... but if it had been a fueling problem what could possibly cause the symptoms that 1 day disappeared?

The engine continued to sound lovely, until at 144k some twat (now known as the 'third party') pulled out in front of me and DesTroYeD my baby...

So i'm not sure if you think your sound could be the same, or if you got it sussed yet? But i hope my story can add some pieces to the puzzle and attract some advice to our problems...?

Many thanks