DB9, problem with oiled up Air Filters
Discussion
Hello, I email to ask if you can help me with some advice.
I have a 2005 DB9 Coupe with 40k on the clock. I have issues with the airfilters, they get oily and need replacing every 10 – 12 weeks, they could go a bit longer, but after 10 weeks they look like this
New one on the left, 10 week old on the right. Both sides of the engine’s airfilters are oiled the same, this is what is confusing, as if one side of the engine was oiled and one clear, then I could look at the one side. But both sides are EQUALLY oiled.
The exhaust blows clear, no puffs on start up, revving, driving etc. Although inside the exhaust pipe there is clean perfect black dust / smoke particles. Although this might be a Red Herring as I changed the rear exhaust box and got rid of those pesty silencers (it sounds nice now), so the dust particles cannot get caught in any muffler.
The oil is trickling down the air intakes, and fowling the filters. The car uses about a litre of oil every couple of months, which I am told is not bad, especially as I drive about 1000 miles a month. There are no oil leaks.
The engine is a bit noisy and I’m looking at the lifters, but I don’t want this to be another Red Herring.
What just adds to the confusion is that the car drives like a dream, with really really oily filters the engine, “hunts”, at tickover, other than that it drives great. When I change the Airfilters for new ones, the car drives like a dream. There is no loss of power, no misfire, no overrun. It drives brilliantly WITH oily filters, when they are clean she runs likes a turbine.
My question is, should my airfilters be like this? Is it a design fault? Am I driving a supercar like a daily hatchback and as such should I accept this level of maintenance?
Any suggestions?
Thanks
I have a 2005 DB9 Coupe with 40k on the clock. I have issues with the airfilters, they get oily and need replacing every 10 – 12 weeks, they could go a bit longer, but after 10 weeks they look like this
New one on the left, 10 week old on the right. Both sides of the engine’s airfilters are oiled the same, this is what is confusing, as if one side of the engine was oiled and one clear, then I could look at the one side. But both sides are EQUALLY oiled.
The exhaust blows clear, no puffs on start up, revving, driving etc. Although inside the exhaust pipe there is clean perfect black dust / smoke particles. Although this might be a Red Herring as I changed the rear exhaust box and got rid of those pesty silencers (it sounds nice now), so the dust particles cannot get caught in any muffler.
The oil is trickling down the air intakes, and fowling the filters. The car uses about a litre of oil every couple of months, which I am told is not bad, especially as I drive about 1000 miles a month. There are no oil leaks.
The engine is a bit noisy and I’m looking at the lifters, but I don’t want this to be another Red Herring.
What just adds to the confusion is that the car drives like a dream, with really really oily filters the engine, “hunts”, at tickover, other than that it drives great. When I change the Airfilters for new ones, the car drives like a dream. There is no loss of power, no misfire, no overrun. It drives brilliantly WITH oily filters, when they are clean she runs likes a turbine.
My question is, should my airfilters be like this? Is it a design fault? Am I driving a supercar like a daily hatchback and as such should I accept this level of maintenance?
Any suggestions?
Thanks
Both of your PCV valves have gone. There is a single pipe which runs up the back between the bulk head and engine, this splits into two and the splits into two again. It has a one way valve to ventilate positive crankcase pressure and stop oil vapour from entering the air intake system. They are an absolute b
d to change and generally don't last very long if you do. On each bank of cylinders a pipe runs between the banks and outside the banks. They reconect on the throttle body's. On the near side the pipes join the intake just before the butterfly, one each side of the thottle body. Oil condenses in these pipes and collects in the bottom of the throttle body and when the engine isn't running can spill into the air intake pipe. As this is downhill from the throttle body to the air filter box naturally the oil runs down to the air filter box and fouls the filter. This can also cause problems as the grim from the air intake mixes with the oil vapour and builds up at the base of the butterfly cause inaccurate throttle sensor readings. It is probably this cause your engine to "hunt" on tick over.
There is an foul safe fix which stops this altogether although its not exactly what you would expect for a top marque. If you want the details and an electronic copy of the workshop manual email me.
d to change and generally don't last very long if you do. On each bank of cylinders a pipe runs between the banks and outside the banks. They reconect on the throttle body's. On the near side the pipes join the intake just before the butterfly, one each side of the thottle body. Oil condenses in these pipes and collects in the bottom of the throttle body and when the engine isn't running can spill into the air intake pipe. As this is downhill from the throttle body to the air filter box naturally the oil runs down to the air filter box and fouls the filter. This can also cause problems as the grim from the air intake mixes with the oil vapour and builds up at the base of the butterfly cause inaccurate throttle sensor readings. It is probably this cause your engine to "hunt" on tick over.There is an foul safe fix which stops this altogether although its not exactly what you would expect for a top marque. If you want the details and an electronic copy of the workshop manual email me.
With the expanation above the oil would therefore be fouling the inside of the filter as the airflow through the filter is from the outside to in, isnt it? The inside of the filter looks clean and it is the outside that appears to be fouled.
I would be more inclined to look for an engine oil leak somewhere near the air intake to the filters and see if it is being sucked in. It would not take much of a leak to cause the symptoms you have. I have a Vanquish so I'm not exactly sure of the set up on the DB9. However on the Vanquish the inlet to the air filter is a long way from the engine so I may well be just adding a red herring.
I would be more inclined to look for an engine oil leak somewhere near the air intake to the filters and see if it is being sucked in. It would not take much of a leak to cause the symptoms you have. I have a Vanquish so I'm not exactly sure of the set up on the DB9. However on the Vanquish the inlet to the air filter is a long way from the engine so I may well be just adding a red herring.
Opposite on a vanquish to a DB9. Db9, clean air into the center of the filter, through the filter to the outside to the engine.
Although I suspect that from what the OP says the filter is saturated right through. PCV problems are common on DB9's its the main reason you have to clean the throttle bodies at every service although most dealers don't bother and wait for the inevitable resulting work and invoice opportunity.
Although I suspect that from what the OP says the filter is saturated right through. PCV problems are common on DB9's its the main reason you have to clean the throttle bodies at every service although most dealers don't bother and wait for the inevitable resulting work and invoice opportunity.
3200gt said:
Opposite on a vanquish to a DB9. Db9, clean air into the center of the filter, through the filter to the outside to the engine.
Although I suspect that from what the OP says the filter is saturated right through. PCV problems are common on DB9's its the main reason you have to clean the throttle bodies at every service although most dealers don't bother and wait for the inevitable resulting work and invoice opportunity.
Ah That explains it. Yes lots of info on failed PCV's on the AMOC site. Although I suspect that from what the OP says the filter is saturated right through. PCV problems are common on DB9's its the main reason you have to clean the throttle bodies at every service although most dealers don't bother and wait for the inevitable resulting work and invoice opportunity.
Hello Boys, wow, thanks, I'll get on to this today.
Just for clarification I took the air filters off myself, the first one took about 3 hours because I didn't have a clue and my manual was on a computer in the office. The second filter took about 20 minutes.
Having stripped the whole thing down looking for where the oil was coming from (and not finding it), I can confirm that the air is sucked (or pushed in) through either side of the main front grill, the air goes down a plastic tube and hits the outside of the paper airfilter, the air is sucked through the filter and up into the engine.
Originally I though that my filters were oiling up from the outside-in. But now I can see (and I took long enough to take it all apart), the oil is coming from the engine down the air intakes and oiling up the filters from the inside-out. When I took the filter housing out, the dirty air coming from the atmostphere was bone dry and only dust was in the plastic intake.
All your feedback is fantastic. Thanks, and I can understand why Dealers don't clear things out when they service cars, why should they...! I could see the best part of a £1,000.00 written all over this problem If I didn't have a forum like this and the, "ummph", to take the dam thing apart.
Does the above information change any info given ........
Thanks again
Just for clarification I took the air filters off myself, the first one took about 3 hours because I didn't have a clue and my manual was on a computer in the office. The second filter took about 20 minutes.
Having stripped the whole thing down looking for where the oil was coming from (and not finding it), I can confirm that the air is sucked (or pushed in) through either side of the main front grill, the air goes down a plastic tube and hits the outside of the paper airfilter, the air is sucked through the filter and up into the engine.
Originally I though that my filters were oiling up from the outside-in. But now I can see (and I took long enough to take it all apart), the oil is coming from the engine down the air intakes and oiling up the filters from the inside-out. When I took the filter housing out, the dirty air coming from the atmostphere was bone dry and only dust was in the plastic intake.
All your feedback is fantastic. Thanks, and I can understand why Dealers don't clear things out when they service cars, why should they...! I could see the best part of a £1,000.00 written all over this problem If I didn't have a forum like this and the, "ummph", to take the dam thing apart.
Does the above information change any info given ........
Thanks again
Hi.
Oil pullover on DB9 is common problem for the reasons stated on this thread (breather valves), there has been some excellent advice here on PH indeed and most probably, as I have seen on too many cars, the breather valves are to blame.
However, on 2 cars we have seen there has been quite a rattle on small throttle blip from idle, it is possible to confuse oneself the rattle is the valvetrain, it is in actual fact worn throttle blades. The rattling comes from the blade going past minimum blade position (circa 3 degrees) going fully closed, and when the blade momentarily closes the contact between blade and body housing causes a rattling which does very much sound like valvetrain rattle. This is important here because when on long periods of overrun the throttle blades will close past minimum blade angle and the result is very low manifold absolute pressure which pulls over into breathing system / inlet manifold LOTS of oil.
It is very sad, but too often now we see owners caught out by this common problem and the result is damaged engine due to oil starvation. It is so important to keep a regular check on oil level because the car was not fitted oil level sensor.
Sounds like your well on the road to recovery, good luck and if you need any help along the way whilst you repair the problem yourself don't hesitate to give us a call.
Oil pullover on DB9 is common problem for the reasons stated on this thread (breather valves), there has been some excellent advice here on PH indeed and most probably, as I have seen on too many cars, the breather valves are to blame.
However, on 2 cars we have seen there has been quite a rattle on small throttle blip from idle, it is possible to confuse oneself the rattle is the valvetrain, it is in actual fact worn throttle blades. The rattling comes from the blade going past minimum blade position (circa 3 degrees) going fully closed, and when the blade momentarily closes the contact between blade and body housing causes a rattling which does very much sound like valvetrain rattle. This is important here because when on long periods of overrun the throttle blades will close past minimum blade angle and the result is very low manifold absolute pressure which pulls over into breathing system / inlet manifold LOTS of oil.
It is very sad, but too often now we see owners caught out by this common problem and the result is damaged engine due to oil starvation. It is so important to keep a regular check on oil level because the car was not fitted oil level sensor.
Sounds like your well on the road to recovery, good luck and if you need any help along the way whilst you repair the problem yourself don't hesitate to give us a call.
So a combination of a worn throttle blade or/and the failure of what is probably an inexpensive breather value component, can cause a catastrophic engine failure; frightening!
I wonder if valve failure is mileage or age related. Because if it’s age related, being tempted to extend your service intervals, because of low annual mileage, is definitely not a good idea.
F1 NDW said:
I'm sure you will indeed have the potential to join the fun Nick.
Frankly Neil its a bloody nightmare. Being honest I am st at checking oil because my other cars have a built in warning system. Except the old 110 and TBH if that blows up it will cost a round of drinks to fix. Oh the worry 
MaverickAM9 said:
.....I took the air filters off myself, the first one took about 3 hours because I didn't have a clue and my manual was on a computer in the office. The second filter took 20 mins.......
I feel for you. That sound exactly like my experience every time I try and do something myself on the 9. I must say though, I do feel a good sense of satisfaction after all the rigmarole and it's all back together!FF
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