Cold start issues, c5 2lt hdi

[Dunkah]

Hi everyone and merry Christmas to all.

Had some cold starting issues recently on my C5 tourer, 2008 plate, 2ltr hdi.

Car has 115000 miles on it but I look after it ready well.

First started when we had a really frosty week back in November, left work late one evening and car wouldn’t start, been sitting all day in 0° weather, it took about 12-15 turns of the key before it finally kicked into life. After that it was ok for a few days, then another frosty day and same again. I thought do the simple stuff first that it could be, fitted a new MAF sensor, a good brand one, Lucas, but unfortunately no change, still occasionally didn’t want to start. Thought I’d put a new set of glow plugs in, I know they’re not too important for starting but I thought maybe if I found one that was totally corroded and crapped out that could be it, old plugs looked ok but new set went in anyway. I plugged it into a lexia after that just to see what it said, the only obvious problem that came up that could be running issue was the camshaft sensor. I chatted with a mechanic mate of mine, he said that’s really quite important and could quite possibly be the issue. I fitted a new cam sensor, again, good brand, Bosch, then I cleared the fault code with the lexia.
That was a month ago and was doing fine, the weather since has been very mild but we have had a few frosty mornings, 0°, occasionally -1° and still doing fine, no issues at all.
Then leaving work this evening, a bit cold but not frosted, 4° or so, and big starting issues back again, it took about 25-30 turns of the key before it actually kicked into life and idled.
Not sure where to try next…..

Here’s a couple things I’m thinking….. I didn’t replace the glow plug relay and I know relays can get a bit sticky when cold if they’re on their way out.
Also, when it did kick to life this evening, I thought I’d just try it. I put my foot on the accelerator pedal all the way to the floor and turned the key, it started but took a couple of try’s, the rev hunted up and down for a few seconds then revved up as I had my foot down. Not sure it that actually had anything to do with it or is just a coincidence but worth a mention.

If anyone has any thoughts or opinions or has experience of anything similar and can shed any light on this I’d be very grateful.

thanks all, and once again, merry Christmas

[the-termin8r]

I think you've missed the most simple step here: check the battery. C5s are notorious for being very picky about their batteries, they'll reject batteries that other cars can get plenty of further use from. Additionally, are you letting the glow plugs pre-heat? Turn the ignition on an give it a few seconds. I typically wait for the suspension pump to stop working before turning the engine over. Check to make sure your battery terminal clamps are seated properly and haven't come loose or cracked.

[Dunkah]

Hi Rob, merry Christmas and thanks for your response.
You raise a couple of valid points there.
I do always wait at least for the glow plug light to go out, but maybe I’ll give it a few seconds more in future.
The battery I think is good, it’s less than two years old and doesn’t exhibit any other electrical issues, but, yes the terminals could possibly do with a clean up, I’ll get that done soon.
Thanks

Also, just tried it this morning, been sitting all night and currently 3°, started first time

[furriegurrie]

What isn’t clear to me is if anything happens when you say you are turning the key 25 to 30 times. Do you mean you turn the key and nothing happens (except maybe a click?) or does it take a lot of revolutions of the engine before it starts?

[the-termin8r]

Hi Rob, merry Christmas and thanks for your response.
You raise a couple of valid points there.
I do always wait at least for the glow plug light to go out, but maybe I’ll give it a few seconds more in future.
The battery I think is good, it’s less than two years old and doesn’t exhibit any other electrical issues, but, yes the terminals could possibly do with a clean up, I’ll get that done soon.
Thanks

Also, just tried it this morning, been sitting all night and currently 3°, started first time

Merry Christmas.

The battery before my current one in my 2L was a Bosch S4 and I only got a couple of years out of it. I suspect I got one out of a bad batch though because the car had another S4 before that and it got a good 6 or 7 years. I'm now running the same Varta Silver Dynamic in both the 2 and 3L and both have been fine. That actually reminds me, I need to go and run up the 2L for a bit later today as it's been sitting for over a week lol.

Do you find the car sitting in economy mode very often or going into it quicker than usual? That's typically the first sign of a failing battery, then come a bunch of unpredictable and random electrical gremlins that you wouldn't necessarily attribute to the battery.

It's also worth checking to see if you have a correctly rated battery because you get a range of ratings for a given form factor. I always go for max capacity and current delivery. I think My Varta is something like 78Ah and 780A (CC).

[Dunkah]

What isn’t clear to me is if anything happens when you say you are turning the key 25 to 30 times. Do you mean you turn the key and nothing happens (except maybe a click?) or does it take a lot of revolutions of the engine before it starts?

Sorry, yeah I could have been clearer about that.
It turns over fine, then either doesn’t fire up or fires up but dies instantly. The cranking seems totally fine, just won’t catch and fire up.

[Dunkah]

Hi Rob, merry Christmas and thanks for your response.
You raise a couple of valid points there.
I do always wait at least for the glow plug light to go out, but maybe I’ll give it a few seconds more in future.
The battery I think is good, it’s less than two years old and doesn’t exhibit any other electrical issues, but, yes the terminals could possibly do with a clean up, I’ll get that done soon.
Thanks

Also, just tried it this morning, been sitting all night and currently 3°, started first time

Merry Christmas.

The battery before my current one in my 2L was a Bosch S4 and I only got a couple of years out of it. I suspect I got one out of a bad batch though because the car had another S4 before that and it got a good 6 or 7 years. I'm now running the same Varta Silver Dynamic in both the 2 and 3L and both have been fine. That actually reminds me, I need to go and run up the 2L for a bit later today as it's been sitting for over a week lol.

Do you find the car sitting in economy mode very often or going into it quicker than usual? That's typically the first sign of a failing battery, then come a bunch of unpredictable and random electrical gremlins that you wouldn't necessarily attribute to the battery.

It's also worth checking to see if you have a correctly rated battery because you get a range of ratings for a given form factor. I always go for max capacity and current delivery. I think My Varta is something like 78Ah and 780A (CC).

Now you mention it, it has been doing economy mode a bit. If I’m loading stuff in and out with the door open for quite a while, or cleaning it then yeah it goes economy mode more often than I’d like.
Good point there, thanks

[Chris570]

One thing to try would be to give the primer bulb a couple of squeezes before attempting the start if you suspect it will be difficult.

Reason being it's not unheard of for the lines to have air ingress and that would manifest in a similar way to what you're describing. Mine does this from time to time....

If nothing changes, then at least you've ruled it out and it hasn't cost you a penny.

[PaulC5]

Sounds like a fuel problem. Possibly there is an air leak on the filter and it is letting the filter drain back to the tank between trips. Has the filter been replaced recently or is it due ? You can also check the immobiliser is recognising the key - leave it in the ignition with the engine off and open the driver's door, if recognised there is usually a warning message.

[Dunkah]

Sorry for my slow response, currently juggling family visits and work during Christmas week….
Thanks for your responses Chris and Paul, you’re both suggesting fuel being a possibility. That’s interesting as I did replace the fuel filter recently, back in October. I did pump the hand bulb when I did that but haven’t checked it since, definitely something to look at, maybe I still have an air lock in there maybe or a line not sealing as it should.
Something to look into.
Thanks

[aerodynamica]

Each time I replaced the fuel filter on mine I always notice that the fast release fuel pipe connections have a looseness to them when connected. Always makes me feel like they'd not seal well but no issues so far