Slow starting issue..

[Imola_Sid]

Right guys, I've had my C6 for around a month now and have probably covered a thousand miles or so.

One issue that is starting to bug me is the lazy/slow start. Since purchasing the car there hasn't been a single occasion where it's failed to start, however, every time I start the car it struggles to start. I think it's a bit better when cold but may just he imagining it. The last owner changed the battery in 2021 I believe. If i press the start button (ignition on) and turn it off and then start the car I think starts a bit easier.

Any thoughts?

[Jim Haseltine]

It'll get worse to the point that starting (especially when hot) will become a lottery. I found that sometimes my battery booster pack would help a bit but even with it a couple of times I was left waiting around for an hour or so until the car cooled sufficiently.
It's usually caused by the righthand turbo cooking the starter, the solenoid and the main cable.
When I replaced them the cable mounting stud was loose in the solenoid case and this is what the cable looked like:


And yes, it's an engine out job. With the engine out and the RH turbo off I still found it difficult to get the old starter out and the new one back in as the RH engine mount restricts the space available to move the starter. Not wanting to have to do the job again anytime soon as I've pulled the engine too many times for my liking over the last 3 years I fitted heat shielding to both the cable and starter.

[VaudiGR]

How many miles have your cars covered since it started to develop this issue?

Sent from my SM-S908B using Tapatalk

[Jim Haseltine]

Mine started being noticeable at around 110K and lasted through to 116K before I changed the starter. If I hadn't had new turbos to fit I'd probably still be trying to live with it though.
The plastic plug on the exciter cable gets cooked too and most likely will shatter when being removed from the solenoid. Part number is 1K0973751 - they're used on just about every modern ICE VAG car and cost very little.

[Imola_Sid]

Fantastic news

Mine has 118k miles on it.

[cammmy]

Ah crap, looks like I'm in for this at some point too. Mine hasn't failed to start but it doesn't turn over as quick as I'd expect.

[welwynnick]

My wife's old car started slowly for a long time, and then the battery died, and it wouldn't even turn over.

I disconnected and cleaned all the power and ground connections, and while I was in there, I removed and stripped the starter motor (bit of a game). In the past I've had to replace worn brushes, though not this time. I cleaned everything and put a little bit of grease in the gearbox and bearings.

None of that made the car start. But when I put a new battery in, not only did it start, but it also started more quickly than it had done for many years. Always grudgingly reliable but worryingly languid, it was now positively enthusiastic, and burst into life every time. So now I'm a fan of getting my hands (very) dirty on starter motors, though recognise it's a bit more difficult with a V10 than a 4 cylinder.

Nick

[Imola_Sid]

I'm sure i've read in another thread somewhere that it could also be fuel pump related which is why it's sometimes a little better starting after switching the ignition on and off a few times before starting the engine.

Although, from Jim's post it does sound like I have the same issue.

[welwynnick]

Does slow starting mean that the engine turns over slowly, or that it turns over a long time before it starts?
The fuel pump and any non-return valves will only affect the latter.
My experience is that starter motors and their connections affect both.

Nick

[cammmy]

Mine turns over a bit slow but only needs maybe 3-4 revolutions to start. I was thinking it might be the battery. Pretty sure it's about 8-10 years old but the car can sit for weeks and still be fine. Seeing this thread though, I wonder if it's a little bit of both battery and cooked starter.

Still starts every time though, so it's going on the list of things to monitor. Already patched the coolant lines but will replace those when I eventually HAVE to take the engine out.

[Jim Haseltine]

I'd never really noticed a problem until one MoT day the workshop manager asked me if it was always sluggish to turn over. I found that it was a little bit better if I started it on the key rather than on the button. Normally if it didn't start first time it would fire as soon as it turned over on the second attempt. Then out of the blue one evening it stranded me. I'd been parked up visiting a business then wanted to move the car to dump some recycling on the same estate, it took 3-4 attempts before it reluctantly fired. If I'd thought about it I'd have let it running beside the skips but no, I stopped it. Wouldn't turn over, just a s-l-o-w wind until the starter stalled. Didn't have a booster pack with me. Had to phone my other half to ferry me home and back again with the booster. After that I always carried it but still got caught out - once very embarrassingly in a Halfords car park on a busy Saturday.

[Imola_Sid]

Ordered a genuine Bosch starter motor.

Do you have the part number for the earth cable?

[Jim Haseltine]

The cable I fitted (which runs from the under bonnet +ve stud to the starter and then on to the alternator) was part 07L 971 225 B. It and the exciter cable plug (1K0 973 751) rushed me a touch over £200 including VAT back in April.

[Imola_Sid]

Thanks mate

[Imola_Sid]

https://www.lllparts.co.uk/product/1K09 ... -1k0973751

https://www.lllparts.co.uk/product/07L9 ... 07l971225b

These the correct bits?