DB9 tickover advice.

[paulrog1]

Hi,

I've got a 2005 DB9, 28K miles, i've got a question about the tickover, it doesn't seem to be ticking over smoothly, occasionally the engine rpm tends to slightly dip and then recover and I can feel the car slightly move, now is this normal? how smooth is the V12 tickover?

The car drives with no problems at all, really smooth, no noticeable misfires or warnings on the dash, i've recently replaced the airfilters and looked at the throttle bodies which seemed clean enough (Is it a good idea to remove these and clean them?) I've also tried to do the rundown proceedure.

I've been meaning to go somewhere where there are some DB9's to have a comparison, but haven't the time, plus i'm nowhere near Aston dealerships, (also not able to get to Burghley because of work commitments).

The car has a full service history, most of the stamps are AM dealers, not a complete list of invoices nothing about the sparkplugs and/or coilpacks been replaced, so assuming they have not.

Am I looking at replacing the coil packs & sparkplugs?

Thanks for your advice.

Edited by paulrog1 on Thursday 23 June 15:31

[SLacKer]

Coil pack misfire is a possibility. Your description sounds like how mine was before the coil pack change I would describe it as a slight shudder when the revs dropped.

[toohuge]

Are you sure it's not the AC compressor engaging?

[paulrog1]

No, it does it even when the AC is switched off.

[toohuge]

Ok.....

In my experience plug and coil issues usually get worse under load, I.e acceleration etc.

It sounds like you've got a stumble at idle - I've seen this before and it could be either an air flow sensor or an oxygen sensor on its way out.

How often does this problem occur? Is it regular , or does it happen once every so often?

Chris

[paulrog1]

Hi Chris,

This happens every 3 to 4 seconds during tickover only, no problems when driving, even booting it.

Thanks for your advice.

Edited by paulrog1 on Friday 24th June 15:19

[dbfarmer]

Hi Paul, I have a car exact same year as yours and at 37000mls or thereabouts it did exactly what yours is doing. There is a bad shudder when idling sometimes. I replaced all plugs and coils and the difference is huge !!
It is supposed to be done at 35000 mls. Money well spent