Starting issue

caterman · 24 Nov 2019

My 996.1 C2 has always laboured a bit when starting , however it now won't start without a booster and it only just catches then. So before I take half the engine bay apart can someone confirm/challenge my diagnostic logic.
Battery and alternator have been tested and are ok and I've cleaned up the batterry posts to make sure there is good contact, lights etc are bright when the engine is on and don't fade that much when starting.
So , I think the likely culprit is the starter motor positive cable. Is there anything else to check before I embark on what looks like a very fiddly job?

deMort · 24 Nov 2019

There will be a battery lead connection on the gearbox .. i would certainly check that for corrosion.

You have an earth lead o/s/r for the engine .. again check that .

i would probably say it was the starter motor over the battery lead on one of these but either way you will see when checking that lead.

It's not a hard job to get at it .. throttle housing and front inlet tract removed .

Always disconnect the battery though before working on these leads

fot0 · 24 Nov 2019

As deMort says with earth straps. The starter lead tends to be problematic on a hot engine with lengthy laboured starting.

caterman · 25 Nov 2019

Thanks both, job started although it's reminded me again that I need to replace the engine cover strut, the lids quite heavy when it drops on your head!

deMort · 25 Nov 2019

Tell me about it :floor:

Customer .. no i don't want to pay for them to be replaced .. Mechanic .. please replace them .. Please !!

caterman · 30 Nov 2019

DeMort ,I feel for you, strut replaced, possibly the quickest simplest job I've ever done on the car.

.....which isn't the case for the cable!

The new cable is now in place. Whoever first thought of taking the plastic end off after heating it , I doff my cap to you, it made threading the cable soooo simple.

Now just got to work out how to get the bl@@dy alternator back in, I got it out without having to move the rear bush but it ain't going back in so just about to rig up a diy press to see if I can get it to move without breaking the alternator.

deMort · 30 Nov 2019

Did you actually see a fault with the old cable .. corroded .. burnt etc ?

Did you replace the starter motor ?

For the alternator bush .. a simple trick ..

A socket such as a 24 mm double depth one ..

Wind the very long bolt into the bush about 1 cm on the alternator ..

Hold the alternator with the socket on the ground and on the bracket around the bush .. the bush will fit inside the socket with the socket supporting the alternator bracket .. big smack with a hammer .. bush only needs to move 1-2 mm and its easy to refit it then .

Socket must fully support the bracket with the steel bush in it basically ...

Never ever just hit the bolt without supporting the bracket .. big problem if it snaps .. you get no exchange alternator if you do .

caterman · 1 Dec 2019

Demort, firstly thanks for the alternator bush tip, didn't work with little taps, took a brave pill gave it a huge bash onto the socket and it moved.

The cable was rusted but not as badly as I expected so before I put it all back together and realise I have been very foolish I thought I would remove the starter motor and properly bench test it, having removed the cables and two bolts I can't budge it!!! Time to call it a day for this weekend and I'll try again in a few days.

One of the blessings of it not being a daily is that I don't have to keep at it to get it ready for monday, there have been a few instances on this job where I've got stuck and next time its worked (or I've had advice on her)

Thanks once again

deMort · 1 Dec 2019

I had the same problem on a 997 last week .. easiest way was a pry bar under it and lift .. didn't take much effort to get it out.

You can use a length of wood if no pry bar .. you just need something to lift it a bit at the back .

As the cable didn't look that bad ... and as the cable fault is usually a 997 problem then im still with its the starter motor thats at fault ... see how you get on with the bench test.

caterman · 1 Dec 2019

Demort, always happy to be proved wrong by someone with your expertise.

One thing I did notice on the starter motor is the third cable which you don't unbolt to remove the motor, I believe that is the earth, if goes back into the body of the motor and that is very rusty, not sure if that impacts the motor operation.

Thanks for the tip in the pry bar, just one last query hopefully, do you know the winning national lottery numbers for next Wednesday? do you happen to

:worship:

deMort · 1 Dec 2019

caterman said:
One thing I did notice on the starter motor is the third cable which you don't unbolt to remove the motor, I believe that is the earth, if goes back into the body of the motor and that is very rusty, not sure if that impacts the motor operation.

Can you get me a picture of this part as i'm not aware of an earth lead there .

caterman said:
just one last query hopefully, do you know the winning national lottery numbers for next Wednesday? do you happen to

Indeed i do .. i'll let you know on Thursday

caterman · 1 Dec 2019

deMort, this isn't mine (its a bit cold and dark out there) its off the Pelican Parts website but its the same configuration as mine, the lead I'm referring to is the bottom right hand one, the lead appears to go back into the body, if not an earth is it the +connection between solenoid and the main motor? The exposed wire at each end is very rusty on mine.

Thanks for the Lottery tip :hand:

deMort · 1 Dec 2019

The right hand connection .. braided wire is the output to the starter motor from the solenoid .. if thats rusty then that may well be an issue .

A solenoid is just a large switch .. in the case of a starter motor then its a copper bar that's jammed against these two connections inside on the picture when you operate the starter .. a poor contact there stops a starter from working or can cause a clicking noise and not work .

bullet-proof_biscuit · 2 Dec 2019

Check resistance of power cable by measuring volts at battery then volts at starter motor +Ve, should be less than 0.5v drop, any more and chance cable.

I have same lazy hot start issue (2004 997), replaced power cable, bit better, replaced battery (Yuasa HSB110 [800CCA & 85Ah]), bit more better, still not as new so I've ordered a starter, best price for a genuine Bosch I've found is £170 from Autodoc, Design911 was £165 ish for Hella but may as well go the little extra for Bosch, that was no core exchange either, do it and you'll not have to worry for another 100k miles.

Beers!
HH

caterman · 7 Dec 2019

Thanks DeMort, I am now the proud owner of a prybar, something I thought I would never need, but it worked, I tested the starter off the car and it seemed ok but not really racing so rather than faff about I've put a reconditioned one in.
However in replacing things it looks like I have snapped a fitting on a hose to teh water pump so I've started a new thread on that.

:frustrated:

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