Had this little red car about a year now. Lately, when keying the car to start and holding it sometimes the starter will just stop trying to turn the engine after what sounds like a half or full revolution . Usually the second attempt will start the car normally. This can happen whether the AC is on or off.
Had the battery capacity checked at a car parts place and it tested good at, I think, 550 or 580 amps.
Is this probably a worn out starter motor? What possibly else could it be?

 

I have found that Battery needs to be a minimum of 650ah, to get a clean start. So run C70 with a 670ah battery. Standard Volvo Battery gets tired after only a few months as is to low a rating. Car will start but after 2nd/3rd attempt.

 

Do you mean CCA and not ah?

The standard Volvo battery is not too low of a rating.

 

...what the auto parts place fella testing my battery said. Temp was 70 degrees at the time, so if it was CCA or otherwise it seemed too low after reading what volor said.
So I sought out a new battery, one big enough to cover all considerations. NAPA had a battery listed for my car guaranteed to be a "perfect fit", but it was an inch and a half short lengthwise. While this would have worked I continued looking for one that would fill up the battery holder.
Found one at Batteries Plus. Their website battery finder also indicated the 11" battery was a perfect fit, but they worked with me to find a substitute that was the actual size of the 12 1/2" Volvo battery currently in place. It's CCA is rated at 790 and a warm cranking amperage of nearly 900.
$50 more, but had that installed.....we'll see how it goes.
Please see next thread for an unrelated question. Thks!

 

24 starts with the new battery...2 fails. Start no. 2 and 19 both stopped after at least 1/2 revolution. 2nd attempt successful both times. About the same frequency as before.
I have poked as much amperage at this problem as possible.
Now have an emergency "starter battery" in my trunk, hoping it helps with it's 700 amps if I gin up against a true non starting problem.
Thinking it's the starter. If true, is it best to get it replaced at Volvo or can it be done just as well somewhere else?

 

I have the exact same problem, on a 2008 C70 T5. Took it to a good Volvo specialist who replaced the starter and the ignition switch. No dice. Said it's not the battery either, and the starter signal is not being interrupted, and he's out of options. He said take it to Volvo as a software update just might fix it, or their scan tools, more sophisticated, just might uncover the real cause. This is the 'self-start' option where you can choose to turn and hold the key yourself, or just briefly flick the switch and let the system take over and finish the start pricess until the engine runs. When I do the latter, it almost always (9 out of 10) starts in one go, but if I hold the key manually, sometimes it can take 3 or 4 attempts. Will keep at it and report back.

 

I realize that this is an OLD thread but I have been having the same problem with my 13 C70
New battery and starter, no codes. Has done this for years. Usually cranks for a second when warm and takes several attempts to get it to turn over completely. Dealer is stumped as am I.

Cold seems to be fine usually. Really frustrating even though it has never stranded me

 

I sold our C70 last year and, coincidentally, the new owner texted me yesterday to let me know the problem has gotten progressively worse, and now it sometimes refuses to start altogether. She has also taken it to a few mechanics who have not been able to resolve it. I advised her to take it to an official Volvo garage. Although my son did, just before we sold it last year, to the Volvo dealer in Santa Monica, who said they could not replicate the issue and all was well (NOT!).