Poor engine idle d5

[richard willetts]

Hi all
I dont know if you can help but my d5 runs rough on tickover a local garage says MAFF sensor Northampton diesel say injectors. I know early d5`s suffered from injector probs my car is a 2004 oct facelift model
the car is and has always been serviced by volsa every 12k without fail from new its covered 77k,no loss of power of fuel consumption its just a little rough on tickover and at very low revs in gears 800rpm one fault it has got is the deformed air box and i have been told that could make the MAFF not work
cheers for any ideas ps just cleaned the MAFF with Maff cleaner seams a very slight bit better

[vandenplas1100]

Hi did you sort your car ive got the same symptoms as yours almost a misfire when at idle [lumpy] mine is a 2005 xc70 d5 automatic 163bhp mileage 90.000 anyone know what it could be thanks car showing no fault messages

[v_matt_v]

Have you replaced fuel filter? I would start from that. 2004 onwards should not have any injector problems, but who know sometimes it happens.

How exactly is the air filter box deformed?

By rough idle do you mean that you can feel the engine shaking more than it used to?
It might be that one of the vacuum engine pads is leaking. Here you've got some information about how the engine pads work: http://volvoforums.org.uk/showthread.php?t=90841
At low RPM the pads are soft due to vacuum. If there is any leak then they will be hard and the engine will be shaking more - you'll feel it more.
The best way to check the pads is to disconnect the vacuum hose just after the pads pressure regulator - it's on the air filter box (remember to seal the vacuum hose going to the regulator otherwise you'll get engine service required message) and take the car for a spin. If you don't notice any change in vibrations then one of the pads is leaking.

[mynameishenry]

My 2005 D5 (130k) had very similar issues and, with help from local specialist (Shipham, North Somerset), yesterday we completed the job which cured it completely.

Initially, I'd experienced greater vibration through the car and an ugly lurch when switching engine off. Had both engine mounts done - on removal it was clear they were shot - it as this seemed most obvious start and vibes reduced.

They didn't completely disappear and became progressively more noticeable, with the added issue of an apparent misfire. Same as a number of people, idle speed seemed unaffected and problem diminished beyond 1500rpm, albeit with general roughness and a lack of power.

Fuel consumption also increased noticeably, perhaps 5% on average.

Codes generated showed nothing sinister although at my request the techs did the full compression and fueling tests. This thread gave me a lot of pointers - http://forums.t5d5.org/topic/23896-d...running-again/ - and readout of injector trim levels was eerily similar.
6.xx
6.xx
7.xx
0.00
31.xx.

Techs proposed a series of investigations which a quick mental totaliser told me would be about £300, before we'd got into cost of repair. Fuel filter was replaced a matter of course with no noticeable improvement. Being a bit skint, and with all reading and research pointing to injector/s, I asked them to remove the set, booked them in with local Bosch injector specialist for bench testing and had a full report back next morning.

Suspicions were confirmed with one injector delivering zero fuel at idle, with 3 others on the borders of acceptable across several tests but still OK and the final one good as gold. Had them refurb the one, refitted and I'm now back to (relatively) silky-smooth idle and power delivery.

With injectors out, the tech took the opportunity to have a look at the EGR pipes and, as per so many other experiences, the chamber leading into EGR and both pipes either side were heavily loaded with thick, black gunge - I'd estimate they were narrowed by 50%. A good soak in diesel and a manual scoop out of said gunge (didn't take cover off the top of the engine, that has to be the next job as I removed a few fingers full of gunge from the inlet...) and refitted. I trust this made some contribution to improved consumption.

Will update if anything changes but reckon if you're experiencing this, injectors are most likely culprits. £55 + vat for testing a set of 5, £120 for refurb - easily quicker and cheaper that exhaustive testing.

[cheshired5]

Originally Posted by mynameishenry

£55 + vat for testing a set of 5, £120 for refurb - easily quicker and cheaper that exhaustive testing.

So you paid £120 total to have 5 injectors refurbished?
Who did this?

[green van man]

Originally Posted by cheshired5

So you paid £120 total to have 5 injectors refurbished?
Who did this?

No I read it as 5 tested 1 refurbished. A big saving over new injectors even at £120 a pop.
Paul.

[cheshired5]

Originally Posted by green van man

No I read it as 5 tested 1 refurbished. A big saving over new injectors even at £120 a pop.
Paul.

Re-read it and it does indeed say that just one was refurbished. I had to go through the 9 paragraphs again though.
I reckon such an out of spec injector could have been identified DIY on the drive with a leak test and swapped for £50 with one from eBay.

[mynameishenry]

Originally Posted by cheshired5

Re-read it and it does indeed say that just one was refurbished. I had to go through the 9 paragraphs again though.
I reckon such an out of spec injector could have been identified DIY on the drive with a leak test and swapped for £50 with one from eBay.

I'm sure it could have been done DIY by someone with the knowledge, but I don't have this or the experience to leak test myself. £120 includes a 12 month warranty and key to the whole job (household harmony...) was getting it wrapped up quickly. Waiting for an untested used part + potential for it being as bad as the other, possibly wrong class (which, I understand, would need intervention by a tech who knows his way around the software to inform the engine management what class it now is) just isn't on the menu.

I've kept costs down by doing donkey work myself and nailed the job in 2.5 days.

[mynameishenry]

Originally Posted by green van man

No I read it as 5 tested 1 refurbished. A big saving over new injectors even at £120 a pop.
Paul.

Correct.

It was from DTM in Bristol. Good enough bunch on the whole. Slight blemish, in that they offered an off the shelf refurb for £150 as a 'quicker' fix ("we'll have to wait for parts from Germany, they're shut down over new year") but then miraculously found what they needed when I declined the offer.

As a side note, fuel consumption has improved by 10% doing the job.

[cheshired5]

Originally Posted by mynameishenry

I'm sure it could have been done DIY by someone with the knowledge, but I don't have this or the experience to leak test myself. £120 includes a 12 month warranty and key to the whole job (household harmony...) was getting it wrapped up quickly. Waiting for an untested used part + potential for it being as bad as the other, possibly wrong class (which, I understand, would need intervention by a tech who knows his way around the software to inform the engine management what class it now is) just isn't on the menu.

I've kept costs down by doing donkey work myself and nailed the job in 2.5 days.

When I had my fault, I had no experience either so I asked on here, learnt it and fixed it for £50.
The injector from eBay was already known working and the correct class because it came from a reputable seller who wouldn't waste time sending out duds.
If you've ever put together flat pack furniture, I promise you that diagnosing and changing an injector is easier than that by a mile.