Service Issues: DPF Soot filter full

[Hank3944]

Hello please help me, knowledgeable people......

I have a 2006 XC90 2.4 D5, 185BHP, Manual

I have the dreaded soot filter full message which comes on as soon as the engine reaches temperature after 3-4 miles or so and goes into limp mode.

So far I have had done the following:

* Tried regen on motorway, driven for 45 mins at high revs, this did clear the message but it came back again the next day
* been into volvo specialist for a dynamic dpf regen, dpf cam back as clear, but soot filter full message and limp mode returned. volvo specialist recommended a volvo main dealer software upgrade.
* Booked into volvo for software upgrade, volvo advised no upgrade is available and advised an oil and filter change as fuel can get into the oil and cause problems.
*Took car back to volvo specialist they did more investiagtions and have found the inlet manifold pipe clogged up with soot, so the next thing is to remove the inlet manifold (3 hrs, £195+ vat) to do more investigations to see what going on. they think worst case scenario in could be a new inlet manifold & flap (s) and possibly a dpf.

Please help any suggestions of help greatly appreciated.

I love the car I just need to get it sorted.

[colinbos]

When i got the DPF soot full message, I had split Resonator seals.

Get those checked. Only a couple of quid to buy and 30 mins labour.

[SwissXC90]

Let us know the mileage on the car and the type of driving you do.
A car with 300,000 miles on it being driven only 4 miles a day is a different scenario to a car with 50,000 miles being driven 60 miles a day. In the first the engine stays cold and emits much more soot, and never gets a chance for regular regens. In the 2nd the engine gets up to proper operating temperature every day and has better opportunities to do regens.
As a comparision, my 2009 XC90 with 75,000 miles is used mainly on weekends and for trips, and often gets driven for >30min at a time on the motorway. Yesterday was a 1.25hr drive to the mountains, and the same home in the evening. I have never had DPF problems.

A soot filter full can happen for a variety of reasons:

1. Overfilled oil, causing excessive oil burn and excessive soot into the filter, causing it to clog excessively quickly. An oil change and filter change helps to get rid of old potentially excessive fuel-contaminated oil and fill to the right amount: about 3/4 up the dipstick (with 3 or 4 XXX showing, but no less than 3 XXX showing otherwise oil is overfull). An oil change is thus a good idea, and the Volvo dealer is providing you good advice. Your engine loves fresh oil. Very easy to identify and fix, a good scenario to have.
When was the last oil change? How much shows on the dipstick?

2. Poor air-fuel mixture, caused by a leak in the intake system, causing overcompensation of fuel, and thus lots of soot causing filter to clog quickly. Inspect intake system with a smoke test for leaks, and repair all leaks.
Note: not all intake leaks result in logged fault codes.
But it's gotta be pretty bad to clog the filter within a few days.
Other forum members will tell you roughly how bad....
Easy to identify and fix, a moderate scenario to have, because it could be the intercooler which is damaged / leaking

3. Bad turbo seals causing oil to be burnt in the turbo and clogging the DPF. Not so easy to diagnose, tends to be the last resort after you have exhausted other options. Not a good scenario if it means a new turbo.

4. Worn piston rings causing oil to be burnt and clogging the DPF. Do a compression test to find out. Very much worst case scenario if it means new rings.


A clean of the intake manifold and EGR valve is always good, but soot deposits in the intake manifold and EGR valve are consequences of too much soot in the exhaust, not the cause of too much soot.
Yes, an EGR stuck open will cause it to foul up faster and be a candidate for a cleaning, but I cannot see how this can be the cause of excessive soot.
A clean of the EGR and intake never hurts the engine, and can indeed improve performance. So whilst also good advice, I don't think it will solve the problem

You really need to find the root cause of excessive soot, and then fix it, and then clean all sooted up components of the engine: DPF, EGD, intake manifold.

I am sure some other much more experienced forum members will come up with a few more reasons for a full DPF.... and maybe even refute my own...

[Hank3944]

Thanks guys thats great advice, if it helps the car has been on the isle of wight for a year so i guess a lot of short runs. The last oil change was a year ago approx 4k miles ago. I agree the inlet manifold pipe is not the cause just the result of something else failing.

Appreciate your help, that really helps. I just want to get the best advice to sort the problem out with the least amount of costly investigative work, so getting advice on here from people who have experienced the same is invaluable, thanks you.

[SwissXC90]

My XC90 was on the Isle of Wight last Summer
Not much chance to go hard and fast there except maybe on the road to the Needles...

Anyway you should be changing oil annually, especially on a Diesel, so you may as well do a scheduled oil change.
A proper annual service includes new oil filter, air filter, cabin air filter, fuel filter, and new brake fluid every 2nd year.

(Note: Air filter and cabin air filter are very easy DIY items).

[Hank3944]

Swiss xc, you seem pretty experienced to me...... thanks for the detailed reply, i forgotvto add the cars only got 68k genuine miles on the clock...😩

[Hank3944]

Any more tips anyone?

[Hank3944]

Any passed experiences of soot filter full problems how they were solved and how much it cost is a big help.

[jamie1131]

Does the car burn any oil at all?

I used to live on the Isle of Wight so I know the roads. I’m afraid it’s probably nothing really wrong with your car other than the type of use it gets. My old jeep only ever managed 13mpg on the island to the short journeys and steep hills around Ryde. Steep hills with a cold engine equals lots of soot.
I think you will end up needing a new DPF to sort this out butthe same problem will come back soon enough.

[Hank3944]

Hi jamie, the car is not on the isle of wight now, it was for a year though,