DB11 Problems After Spark Plug Replacement

[RAAM]

I have a 2020 DB11 V8 with 4200 miles. I took it into my dealer (California) several weeks ago for its annual service (4 years). The dealer said that Aston recommends changing the spark plugs at 4 years. So I authorized that. When I picked the car up it seemed fine. After about 10 days though I tried to start it one morning, and although it started it idled very roughly then shut down. I tried to start it again and same issue. It wasn’t drivable and the yellow CEL was on (not flashing). I hooked up an OBD2 scanner to it and it was throwing off fuel pressure and hydraulic pressure codes. It has now been with the dealer for almost three weeks and they still haven’t determined what the issue is. They think it’s a fuel pump problem, but are awaiting input from Aston Martin. The car was running great prior to the service, and what you would expect with such low mileage. I have to think that these problems are somehow related to the spark plug replacement and service, but of course the dealer is saying that they don’t think there’s a correlation. Anyone have any thoughts on this matter and what questions I should be asking the dealer. I’m concerned that if there is a correlation between the service and the problems, the dealer has created further (if not permanent damage) to the engine or other components that I will literally be paying for later (and when the car is out of warranty). Appreciate the assistance. Thank you in advance.

[filski]

Sorry to hear this.

think these are the AMG engines.

Granted I am not a mechanic, but it could be that when they were putting it all back together they may have failed to connect a hose causing an air leak and then engine is trying to compensate maybe, or possibly connected the connectors wrong way around, but would have though the dealer would be fairly competent in these.

how comprehensive is your OBD tool, could you look at graphs or numbers to see what the fuel doing and if there is any compensation for the air coming in?

Hope all could be done on the warranty

good luck

[RAAM]

Thank you. Yes, fortunately all under warranty right now. But that will end soon unless I purchase an extension. I’m just concerned about long term damage, and the fact that the dealer hasn’t been able to identify and fix the problem after several weeks has severely shaken my confidence in the car in general and again its long term reliability.

[Dewi 2]

Interesting that the manufacturer recommended change point is 4 years (which could presumably mean 40,000 miles).
For the VH era V8 cars, the spark plugs change point is 7 years, or 70,000 miles.

As your car has only driven 4,200 miles, examination of one of the plugs ought to reveal a plug in perfect condition.
When my V8V reached 7 years old (only 15,000 miles) the advice was, "We will examine one plug, but changing them now is most unlikely to be necessary. Now 15 years old and running perfectly, but a new set of plugs next year might be sensible.

Is your experience another example, of modern cars being so complex, that they are sometimes beyond the capability of dealer workshops to fix?
My Mercedes dealer recently spent hours, trying and failing to fix a hydraulic boot release mechanism. Fortunately it can be opened using a manual key.

Hope everything is sorted soon for you.

[RAAM]

Thank you. There may be some truth to your observation regarding modern cars. All I know is that the dealer definitely needs support from Aston to undertake the diagnosis and repair, which is somewhat disconcerting and frustrating. Neither appears to be in any hurry to fix the car and get it back to me.

[filski]

RAAM said:

Thank you. Yes, fortunately all under warranty right now. But that will end soon unless I purchase an extension. I’m just concerned about long term damage, and the fact that the dealer hasn’t been able to identify and fix the problem after several weeks has severely shaken my confidence in the car in general and again its long term reliability.

I think in terms of damage to the motor I would argue it would be negligible, although these are performance motors with tight tolerances, from reading your post car started and died so you have not run it long enough like this to kill it or cause severe damage.

I think the reason that the dealer is confused as they are AM franchise and perhaps don't have AM trained techs?

Could be a wild though but given that these are AMG motors could mercedess dealership take a look? Again might be just bit of a mad thought but even if they charge you an inspection fee it may least diagnose the issue and you can take that information back to AM and fix under warranty and possibly claim your expense from them through complaining.

I hope it doesn't discourage you from long term ownership but might be worth extending the warranty

Good luck

[DB531]

filski said:

I think in terms of damage to the motor I would argue it would be negligible, although these are performance motors with tight tolerances, from reading your post car started and died so you have not run it long enough like this to kill it or cause severe damage.

I think the reason that the dealer is confused as they are AM franchise and perhaps don't have AM trained techs?

Could be a wild though but given that these are AMG motors could mercedess dealership take a look? Again might be just bit of a mad thought but even if they charge you an inspection fee it may least diagnose the issue and you can take that information back to AM and fix under warranty and possibly claim your expense from them through complaining.

I hope it doesn't discourage you from long term ownership but might be worth extending the warranty

Good luck

Filski's suggestion of using a Mercedes dealer to fault find may well be a way to go.
A prolific You Tube poster detailed how he repaired a written off 2019 AM Vantage due to front end damage and deployed air bags. What he did find was that his diagnostic tool would not pick up on AM codes but it did when set on the AMG settings. I suspect there will be a fair amount of carry over components from a 2019 Vantage to a 2020 DB11. worth a check
https://www.youtube.com/watch?v=3izf_JfmK2g&t=... starting at 15.55
Best of luck

[RAAM]

Thank you. Yes, I saw that Mat Armstrong video a while ago. Worth an inquiry.

[RAAM]

Thank you. Yes, I saw that Mat Armstrong video a while ago. Worth an inquiry.

[RAAM]

Thank you. Yes, I saw that Mat Armstrong video a while ago. Worth an inquiry.

[V12Vin]

RAAM, fellow AM owner and Californian. Curious to know which dealership if you don't sharing. Thanks.

[RAAM]

V12Vin, let me get this sorted out first. Here’s an update:

The dealer and Aston have advised that the following need to be replaced: the low pressure fuel pump, the fuel control module, the fuel filter, and the pressure regulating valve unit. So, the problem does not appear to be related to the spark plug replacement, but I’m still surprised that a car with only 4200 miles would need these parts replaced. But in any event, that’s the current game plan. Hoping that nothing else has been damaged in the process (catalytic converters?) and that this work will indeed fix the problem. But only time will tell, I guess. Appreciate all of the helpful input here.

[filski]

RAAM said:

V12Vin, let me get this sorted out first. Here’s an update:

The dealer and Aston have advised that the following need to be replaced: the low pressure fuel pump, the fuel control module, the fuel filter, and the pressure regulating valve unit. So, the problem does not appear to be related to the spark plug replacement, but I’m still surprised that a car with only 4200 miles would need these parts replaced. But in any event, that’s the current game plan. Hoping that nothing else has been damaged in the process (catalytic converters?) and that this work will indeed fix the problem. But only time will tell, I guess. Appreciate all of the helpful input here.

Thanks for update!

Re cats, can you demand for them to have a look and take photos to assure you that no damage has bee done? I think not an unreasonable request given the situation you went through.

Also agree at the milage I am surprised for component failure. Fuel pumps tend to go for quite some time, unless I guess controll module has tricked it into working overtime maybe... and burned it out, I think valve unit and fuel filter being changed as precaution as those prob ok but might as well be changed unless valve is controlled via module and also God damaged by the control unit.

[RAAM]

Good suggestion re the cats inspection and photos. I’m hoping that this isn’t the first of a series of successive problems. I’m requesting a complete inspection, and obviously they need to clear the CEL and all codes. I’ll also have them check all electronics, proper operation of the infotainment system, and switches. Wish me luck, please! My confidence in the product has definitely been shaken and even worse, the wife has started to ask questions!

[p102768]

RAAM said:

V12Vin, let me get this sorted out first. Here’s an update:

The dealer and Aston have advised that the following need to be replaced: the low pressure fuel pump, the fuel control module, the fuel filter, and the pressure regulating valve unit.

That does seem like an awful lot to go wrong at the same time. Sounds like they are just throwing parts at the car to try and fix a fuel problem. It may well fix it but do they all really need to be changed?

[RAAM]

Here’s the epilogue: picked the car up last Thursday following replacement of the parts listed above, and so far so good. Car is driving great and sounds like her old self. Everything seems to work and they did a great job detailing the car for me gratis prior to pick up. I’m cautiously optimistic and keeping fingers crossed. Given this episode, I’m inclined to purchase an extended warranty (assuming I decide to keep the car; my lease ends soon and my warranty is in place during the lease term). Anyone have any thoughts on the extended warranty program and the value associated with it. It seems sensible but is not inexpensive. Many thanks again for all of the valuable information and suggestions. Super helpful.

[RAAM]

Here’s the epilogue: picked the car up last Thursday following replacement of the parts listed above, and so far so good. Car is driving great and sounds like her old self. Everything seems to work and they did a great job detailing the car for me gratis prior to pick up. I’m cautiously optimistic and keeping fingers crossed. Given this episode, I’m inclined to purchase an extended warranty (assuming I decide to keep the car; my lease ends soon and my warranty is in place during the lease term). Anyone have any thoughts on the extended warranty program and the value associated with it. It seems sensible but is not inexpensive. Many thanks again for all of the valuable information and suggestions. Super helpful.

[cayman-black]

At that mileage i would have said no to a plug change , ridiculous.

[RAAM]

It’s a fair point, and I wonder if these issues would have arisen if I hadn’t had the plugs changed. But they do appear to be unrelated and purely coincidental. The car does seem to drive well now, though, and theoretically at least, it should drive markedly better with the new plugs (which the dealer rechecked). I’m just keeping my fingers crossed and resume the enjoyable driving.

[8Tech]

Rep!acing spark plugs at 4200 miles is ludicrous and simply a rip-off, 4 years or not.
They do not "age" with time like fluids or tyres and I'll wager your old ones ended up in the mechanics toolbox for later use!
The parts being replaced sound like using a 50 cal to shoot a squirrel! No idea whats wrong so just change everything as they suspected 'some' fuel delivery issue.
Not very good diagnostics process from the dealer.