D5 PowerPulse pipe burst again...

[Hottieshigh]

Took delivery of a new XC90 D5 PowerPulse on 28 June 2019.

3 Weeks later, parked in a public car park, there was a massive explosion – reminiscent of an olden days building site bonfire to which an aerosol had been inadvertently added. It sounded like it came from my car, but the car started and drove fine, and there were no warning lights. However, over the next couple of weeks we became aware it was missing the low down grunt, and ‘kick’, we had so enjoyed when overtaking, particularly on the Essex (UK) country lanes. Took it to the local A&E where they diagnosed and replaced a burst hose connecting the PowerPulse compressed air tank to the exhaust manifold.

(For the few of you not familiar with PowerPulse Technology, it is very clever and the essence of simplicity – when it works. It overcomes low rev turbo lag by injecting a pulse of high pressure compressed air into the exhaust manifold to spin up the low range turbo in a fraction of a second.)

Now this is the second most alarming thing (the most alarming is a bit later) – our local dealer was rather blasé about the whole thing when I quizzed them how and why; “We frequently replace these pipes. Generally the drivers don’t even notice the reduced performance, and we replace them when the cars come in for servicing.”

As a bone-headed and stubborn medical device design engineer, with an overdose of OCD, perhaps I am slightly more mechanically aware than your average XC90 driver which might be an Accountant, or a Head Mistresses, or even a Local Authority Social Services Lead Practitioner?

Moving swiftly on, and now for the most alarming part, last week my dear wife was enjoying a day at home when there was a deafening detonation from the drive way outside… Yesterday our local dealer diagnosed a burst PowerPulse hose.

So I wonder how many proud D5 PowerPulse owners out there are not actually enjoying the PowerPulse performance they were promised, and paid for, but are rather being dragged along behind a popped powerpulse pipe patiently waiting for the next service…?

If you have the sort of luck I have, your last service was yesterday.

[Boatie]

Originally Posted by Hottieshigh

Took delivery of a new XC90 D5 PowerPulse on 28 June 2019.

3 Weeks later, parked in a public car park, there was a massive explosion – reminiscent of an olden days building site bonfire to which an aerosol had been inadvertently added. It sounded like it came from my car, but the car started and drove fine, and there were no warning lights. However, over the next couple of weeks we became aware it was missing the low down grunt, and ‘kick’, we had so enjoyed when overtaking, particularly on the Essex (UK) country lanes. Took it to the local A&E where they diagnosed and replaced a burst hose connecting the PowerPulse compressed air tank to the exhaust manifold.

(For the few of you not familiar with PowerPulse Technology, it is very clever and the essence of simplicity – when it works. It overcomes low rev turbo lag by injecting a pulse of high pressure compressed air into the exhaust manifold to spin up the low range turbo in a fraction of a second.)

Now this is the second most alarming thing (the most alarming is a bit later) – our local dealer was rather blasé about the whole thing when I quizzed them how and why; “We frequently replace these pipes. Generally the drivers don’t even notice the reduced performance, and we replace them when the cars come in for servicing.”

As a bone-headed and stubborn medical device design engineer, with an overdose of OCD, perhaps I am slightly more mechanically aware than your average XC90 driver which might be an Accountant, or a Head Mistresses, or even a Local Authority Social Services Lead Practitioner?

Moving swiftly on, and now for the most alarming part, last week my dear wife was enjoying a day at home when there was a deafening detonation from the drive way outside… Yesterday our local dealer diagnosed a burst PowerPulse hose.

So I wonder how many proud D5 PowerPulse owners out there are not actually enjoying the PowerPulse performance they were promised, and paid for, but are rather being dragged along behind a popped powerpulse pipe patiently waiting for the next service…?

If you have the sort of luck I have, your last service was yesterday.

A somewhat condersending view of most forum members. We may not be 'medical device design engineers' ( I suspect that some are far more technically competent) but most will understand the concept behind PowerPulse. If nothing else we can read.

[tem]

Originally Posted by Boatie

A somewhat condersending view of most forum members. We may not be 'medical device design engineers' ( I suspect that some are far more technically competent) but most will understand the concept behind PowerPulse. If nothing else we can read.

Thanks for this.
Although, I do not have PowerPlus, I read from day one, what it was about.

What I find amazing, is the hose bursting in such a dramatic way, with the car not being driven at the time of rupture.
Is this common?

tem.

[Quacker]

Mine has been replaced twice. Or perhaps replaced once and reattached the second time because the dealer didn't get it right the first time.
No bangs or explosions. Just an enhanced turbo whine type of thing. Not much if any difference in performance either, because, since you are technically minded, you will know that the point of it is to increase the turbo acceleration from idle, so that more fuel can be injected sooner with less soot production. When the pipe is burst, the compressor will run fairly constantly, for one thing and my ears are not good enough to detect that, but the point being that the same fuel dose as before will be injected, so the performance will hardly be changed, if at all. It will run dirtier though, but the DPF should catch that but could block or regenerate sooner.

Lesser cars with neither twin turbos or power-pulse can and do inject far less fuel into the engine off idle in order to reduce the excess fuel derived soot. My Ranger pickup does this and is a pain to pull out of an uphill junction because it hardly accelerates for two or three seconds, until turbo pressure has built up enough for full bore fuel to be injected, then off it goes like a scalded cat. Not an issue once rolling on the road at 1200+ revs.

[xsaab]

So should one go for the B5 engine rather than search for a powerPulse vehicle or is it a case of jumping from a slightly experienced technology to a new technology ie out of the frying pan into the fire?

[Quacker]

Originally Posted by xsaab

So should one go for the B5 engine rather than search for a powerPulse vehicle or is it a case of jumping from a slightly experienced technology to a new technology ie out of the frying pan into the fire?

The more expensive mechanical complication you have fitted, the more likely it is to eventually go wrong and cost money to repair. Whether Power Pulse is more or less reliable than a supplementary electric motor/generator and battery system is anyone's guess. Frying pan and fire come to mind. Leave the bonnet closed and don't worry about it while it works. Both will probably work for many many years, albeit with the occasional car having a spasm now and again.

[familymangreg]

Yep, in three years of ownership I can't easily now recall the number of times the car has been in for hose related issues, once on the back of a truck as it went into limp home mode!! I've had the big pop and hiss when coming to a stop once and the system blew (after driving up a very steep hill) too.

Then when I purchased a genuine 2 year extended warranty last month, I was informed that it covers everything like the original warranty, apart from hoses!!!! P1ss takers!

Spent a bit of time riding around in newish X5 40d's and M50d's owned by other family members recently... smooth, quiet, much more powerful and returning better fuel economy! Also recently test driven a Q7, Disco and new Touareg.

Then I get back in the Volvo and think what a sh*t engine this really is!!! Courser, louder, way less powerful than all the above and no more economical. The Volvo is a better car than the other is many ways, but the engine, no, just no.

:wq

[Nerdy Norm]

That's interesting. A few months ago, I was driving through a mountain tunnel and heard a big bang, like an explosion. I thought it sounded like it was coming from behind me, but on checking my mirror I found there were no vehicles following me.

I remember at the time checking my dashboard, but nothing was amiss. I didn't notice any reduction in performance, although I do seem to have a lot more diesel clatter at certain throttle positions nowadays.

The car has been serviced since this incident, but nothing was mentioned to me about replacing a hose. Does anyone know exactly what/where to look under the bonnet to see if anything's visible?

[familymangreg]

Not sure if anything can be visible, guess it would depend if/where the problem is. On one occasion for me is was a split pipe, on others a poor connection.

Listen for a PowerPulse compressor running for a while at start up (near offside front wheel arch), or listen under the bonnet immediately after switching the engine off for a hissing sound.

My wife says she can currently hear a hissing sound when accelerating at lower speed, particularly on narrow/walled lanes where the sound is reflected, so I'm starting to suspect a problem again.

:wq

[tem]

When driving through a tunnel, it can be very difficult to determine where a noise is coming from.
The longest tunnel that I have been through, is the Gotthard, between Switzerland and Italy, some 17km long.
I have heard some weird and strange noises on that route.

tem.