Loosing power - Aston Martin DB9 09

[WROUPSTER]

Hi everyone,
Last week-end I took the beast out (DB9 09) and after half an hour of riding it started coughing and losing power. I was able to drive for another half hour to get home (no choice) and the issue persists. Loss of power and it doesn't take its turns. However, there are no warning lights on the dashboard, no particular smell or noise.
You will see beelow the Foxwell OBD reader and here's what it came up with.
Could it be an air filter problem or the coil pack?
Many thanks for your help.
Thank you very much for your help.

[Caslad]

Someone cleverer than me will be along with a diagnosis I’m sure but for now don’t drive it with a misfire.

[AM4884]

Good luck with this!

IF I was faced with this, I'd pull the air filters and check for oil. Do you have oil cups in your EGR lines to catch excess oil returning to the intake?

I would also check the wiring harness where it goes into the ECM to make sure it's not pulling down on the connectors. I started getting random errors with mine from that occurring. I pushed the wires back into the connectors and all was well...

But, it looks like coils if the wires are good. How many years/miles on them?

[ian448]

I had a similar issue earlier this year, car idling for 10mins then suddenly started running like a bag of bolts , engine managment light also came on. From recolection the codes on my foxwell were similar to yours
I removed both throttle bodies which had a light coating of oil ( pcv needs changing) a quick clean with carb cleaner and refit and engine back to running as normal.
Worth a look , its only an half hour job.

[WROUPSTER]

Hi guys,
I cleaned the butterfly as mentioned in your message, it was full of oil but that didn't solve the problem...
I also looked at the air flow at idle and there's a big difference between the two values. How do I know if it's the air filter that's moved or is obstructed, or if it's the MAF that's no longer working properly?

[ian448]

the maf sensors are pretty easy to get to , Aston1936 has a good write up about getting them out and cleaning, that is a fair amount of oil in/around your throttle bodies so could have easily ran down and contaminated the sensors

[AstonKeeper]

As above, some good advice here. But check your history to see if the coil packs have been changed. Post 2010-11 they are slightly improved and significantly less likely to fail.

Aston recommend changing them as part of one of the major services. But honestly past 2011 it's probably unnecessary.

Depending on where you are, happy to come have a look.

[WROUPSTER]

The car has 120.000km and the coils pack was done in 2016 at 77.000km.
I don't know why there's such a difference between the two air intakes if it's a problem of coils packs or PCV valve?

[ian448]

Any problems with the maf voltages would flash up either a p0102 code (below .24 volts) or a p0103 code ( above 4.8 volts) and usually put on the EML although the voltage on one does appear to be low on idle .063v. Plus on the same Maf the grams per second is low at .14 should be between 2 and 7 normally. I would take them both out and give them a good clean.

[WROUPSTER]

Hi guys,

Thank you very much for your help.Quick update, it was the mass flow (Bank 2) that was broken. I have replaced it and everything is working fine.
But... I noticed misfires on Bank 2 but nothing on Bank 1... How can I tell if there are cylinders that are not working properly or if it's a more general problem on this part of the engine (i.e. I have quite a lot of oil coming back through the intake).
Perhaps I should make a separate topic.
Thanks for your help

[Dewi 2]

Talk on AM PH about coil packs, I think mostly involves the V12 engines.

Do the V8s have coil packs and if so, why is there so little talk about them ?

[dbs2000]

The first screenshot is reporting misfires which would lead me to the coils.
I think you need to get the proper diag tool plugged in. My OBD reported that the coils needed doing but the AM dig tool also showed that one of the fuel pumps was low on pressure.

[mrpseudonym]

40,000kms since coil packs were last changed .. you’re due..

[AM4884]

If you haven't installed oil catch cans, it's worth the effort. It took about 20 minutes, and about $50.00 in parts/hoses to install. Seems to keep the oil from going back into the butterflies, where it ultimately collects and then drains down into air filters (presumably when the engine is shut off).

[Calinours]

mrpseudonym said:

40,000kms since coil packs were last changed .. you’re due..

Seriously ? Due for coil packs every 25,000 miles ? At a cost of £/€/$ 0000’s

I don’t mind changing all the plugs, leads, and coil in my old V8, at that interval or 3 x more frequently. But then (all) the plugs cost £30, the HT leads cost the same, as does a new coil… £100 all in.

Progress huh….

[mrpseudonym]

Ah yes I remember the days of distributor caps and HT leads. And it is not with fondness

Back to coil packs though .. the first problem is that they don’t all fail, so if you were DIY you could just replace the failed one. But the problem is if you are getting the dealer to do it is is economical labour wise to do them all. And then there is the matter than on a V12 everything is x 12.. so you are already up for 50% more cost than your V8 at a minimum

[WROUPSTER]

Hello everyone,
Thank you once again for your answers. Unfortunately in France there aren't many Aston Martin specials apart from the dealers.
I think the next step is to change the spark plugs and ignition coil as well as the PCV valve, a tough job for a DIY but well worth it.
I've looked at the fuel pump value and it seems to be in line with the operating values.
On the other hand, a closer look at the misfires on the diagnostic tool reveals a high value for the A1$82 monitor which refers to the following description according to ASTON MARTIN: A1$82: Highest catalyst damage misfire and catalyst damage threshold misfire rate (updated when DTC set or clears).
Does this mean that, in addition to the work mentioned above, I have to consider changing the primary catalyst?... I'm worried, as the price is so high...
If it helps to make a better diagnosis, I also have the following values on the monitor:
A1$80: 0.00
A1$81: 0.12
A1$82: 2.33
A1$83: 0.00
A1$84: 587.8


Many thanks for your help.

[dbs2000]

The only way of checking the catalyst is to inspect it with a camera:

https://www.youtube.com/watch?v=niwamOI4Oos

The chances are you're probably ok, I had an awful misfire on mine and had to limp it home but there was no damage and its running beautifully again. You really need to fix the misfire though.