Kpj

Hey Guys,

For the last week or so, I've noticed that my car takes 3 to 5 seconds to turnover/start. It's normally very snappy and ignites within a second or two of touching the start button, but now it struggles and barely catches. Once I'm up & running, everything seems fine. No hesitation with acceleration. I'm not too car savvy, so I'm guessing this could be the starter?

I'm showing no errors on the dash and plan on connecting it to the VAG-COM, but any idea what it could be? (It's a 2005 A8L W12).

Thanks,
Kpj

MP4.2+6.0

Hesitating like starter just turns over normally but it doesn't catch? Hesitating like starter turns slow? You mention starter, but not enough to go on. There are both the ignition and fuel system too, but way too little info to go down those paths.

Meanwhile, if I were to WAG pending further info, first place I would look if starter is balky/slow is not there but the battery. Would make starter slower in its speed if battery is fairly down, plus can affect ignition if supplied juice is well off. Once you start car, alternator kicks in to deal w/ it, hence better running later. How many volts do you have parked and off? Has it ever been replaced? If not, on a 2005 it is a likely suspect just by age and now slow to start symptom. If you have VAG COM, besides voltage reading you would expect to see power mngt system and similar errors if battery is going toward flat.

mishar

If you turn it off and start it again is it same or better?

Mister Bally

Although with a 4.2 V8, see my thread from about five weeks ago regarding the RPM sensor. I cannot post a link using my droid so do a search.

volvopentaman

I'd also suggest the RPM sensor!

I've been struggling with my boat engine, that has been hesitating to start, and the RPM sensor was the problem there too. Started, and ran well, but starting it was a nightmare.

The sensor especially experiences problems when you are starting, once you get the engine running, usually no problems.

I think it's located on the rear of the engine, above the torque converter/flexplate (no flywheel on auto-trans).

mishar

Interesting. And starter engages to what?

Kpj

Thanks for the info guys. Sorry for not going into detail further.

The original battery went kaput last year, so it has a fresh Bosch battery installed. Via the MMI menu, I am showing 100% battery level, so that's not it.

As for restarting just after shutting down, the same scenario happens. The car takes a few seconds to 'catch' and then runs as normal after 5+ seconds. During this phase, the RPMs do drop below 500 and it sounds as if the car will stall (but hasn't yet).

I plan on hooking up the VAG-COM this weekend (as I've never used it before) to see what I find.

I greatly appreciate your assistance!

mishar

Than I would say guys are right, it must be the rpm sensor.

Kpj

Will the VAG-COM indicate an error/notification if I'm seeing nothing abnormal on the dash?

I also have the Bentley manual on hand, so I'm wondering if this is something a DIYer can tackle....

MP4.2+6.0

Yes, VAG-COM will tell you many things the dash readings never do. At most w/ what you describe so far, your Check Engine Light (CEL) may come on eventually.

While RPM sensor is one, I can think of a variety of others--small vacuum leak, MAF sensor a bit off, air injection system not working right, one of the fuel pumps getting tired, etc. Battery is now less likely, but I would pull the real volts data from VAG COM too.