lack of power from HDi - has been off the road for 6 months

[Dazzler]

Thanks for the explanation about the FAP.

To answer my other question about MPG though, would this contribute to a poor overall consumption?

Cheers

Darren

[RichA]

FAP filter takes out the soot from the engine and keeps the exhaust nice and clean. It's used in conjunction with a separated fluid tank which injects a quantity each time the fuel filler is opened. If the tank is empty (often around 60-80k miles you will need the main dealer to refill the system and set the counter (£90ish). It may be that you will also need a new FAP filter (£150-300).

I know it's slightly off-topic, but this sounds interesting and likely to be relevant to me when I'm looking for a 406HDi. What is the FAP filter? What fluid is used, and is it not a DIY thing?

Cheers,

--Rich

[steve_earwig]

It's a big filter on the exhaust, mainly on 2.2 HDis but possibly some later 2.0s (although mine is an '04 but doesn't have one). Worth avoiding if poss. 'cos Pug don't seem to be too good at sorting them when they go wrong.

[RichA]

Ah, great stuff. Cheers for that . I'm only looking at the 2.0HDi, so I guess it's unlikely to matter much .

--Rich

[muffindell]

The FAP filter is actually part of the exhaust system and bolts directly after the cat converter. It's fitted to later 2lt HDi's and 2.2ltr HDi's, it is a requirement that you have them on new cars these days, so lots of potential problems in the future! Basically lots of short trips kill them in the end; if you do lots of longer trips then its less of a problem and they don't get so clogged. You can refill the system with the fluid but a Pug dealer would need to reset the counter.

[DaiRees]

You can refill the system with the fluid but a Pug dealer would need to reset the counter.

Typical! Another excuse for them to empty your wallet! BAStuds

[steve_earwig]

They don't even seem to manage that half the time (queue account emptying BSI replacement )

[teamster1975]

(queue account emptying BSI replacement )

Haven't got one of those

[steve_earwig]

You haven't got a FAP either

[miniman]

OLD POST!!!!???

The car is still the bloody same.
Nobody else here got any ideas?
I need serious help from folks that know their stuff guys.
Cheers

[muffindell]

Have you tried a new MAF? Even though the dealer may say it's okay, it's often not working correctly within range, giving poor MPG and crap performance. I assume that the car used to work okay before it went off the road 6 months ago? You also need to look for split or collapsed turbo hoses on both sides of the circuit, to and from the intercooler(possibly the problem), if this is the case then the car will feel very dead! Also check that the intercooler doesn't leak (like alloy radiators and A/C condensers, they fall apart after several years (7+ perhaps)). Other than that, you may need to look at the injectors (have em serviced), also the high pressure pump (likely low pressure). After that check the engine compression on all cylinders, however in theory if it is low on any one cylinder then the exhaust should blow out black smoke on acceleration (unburnt fuel).

Hope that this helps

Mat

[miniman]

Hi Mat,
Thanks for the great info. I will go away and try things out.
Hope it gets better soon!!

[Welly]

Mini- I know that you and your Scotish money are like blood brothers but have you actually plucked up the courage to go for a global test at your local friendly dealer? we can only surmise at what may be wrong here

If it's doing the old "max 3000 revs" trick then it's in limp mode because the ECU is unhappy with one or more sensors' readings. Simple faults like the throttle pot will throw up limp mode but the ECU will slowly allow stuff back in once it's worked out what it can cope with. Big faults like low boost pressure will throw a permanent limp (I know this as I'm losing boost through a huge leak until next week).

[leylandp38]

Had something similar i solved only last week with my 406 HDi.

Does it feel like you have no turbo boost?
Does it refuse to rev much over 2800 rpm?

If so check the vacuum solenoids that control the turbo, its the left hand one (looking from the front) that matters for the turbo. You can check it is working properly if you get a vacuum tester (kit is about £40 online for a Sealey or MiniVac). At idle you should draw a vacuum of 500 or so mmHg. As you rev it the vacuum should fall to about 200 mmHg. This is what controls the wastegate.

If the solenoid fails it may draw no vacuum at all, or may hold a constant vacuum as you rev, either way the turbo delivers the wrong boost and the engine management acts to protect the motor, limiting fuel and revs as far as I can tell.

The other thing to test is the pipe connections, one of mine was loose at the join and therefore leaked although it looked OK. Again a vacuum tester is the best way to test all this.

As a quick and dirty test, the 2 (or 3) solenoids are all the same - try swapping them about.

This is a 30 min job to test.

best of luck

Al

[miniman]

That sounds pretty much like it.
It does rev over 2800 most of the time, but sometimes it cant.
I will swap the solenoids over and see what happens. Thanks for the tips, thats just what this site is for!!
Will report back after having a better look at the weekend.