Lazy starter

[axelleveau]

Hi all, I am after some advice as I feel like my start is a bit slow or struggling to get past the first or two compressions when cranking on my N52 (E86 but I guess all N52 cars would have same electrical system)

I changed my battery over the winter as I had a couple of time of failed starts when freezing. Still after that I had some difficult starts or starts that have required a second attempt when temperatures where below 5degC. Even now in warm weather I feel like it should go a bit better over the initial hit when cranking.

I have done some reading and tried to figure out if it could be a ground strap issue. I tried adding a jump cable from engine (oil cooler mounting) to chassis (jump start ground). I feel like there has been a small improvement but might just be my imagination.

So basically at this stage I am after advices on what to check and hopefully not have to blindly change starter. What do you think my ground strap looks like? It is corroded but seems all strands are still attached. (only one I can find across right hand engine mount, is there something else to check?)

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I notice E90s have a strap from head to suspension strut. Should there be one on Z4's too? It seems there is a stud ready to use for that on the lambda cable support.

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I noticed some corrosion on the alternator positive post, I guess it is probably worth checking and cleaning it as well as the bulkhead connections between main battery cable and starter cable? (starter itself is burried under the manifold so I am not keen on going there ye) If nothing helps, is it common for starter to get lazy before dying or do they tend to work until they suddendly don't?

[Rockhopper]

Change the starter. Mine died, the new one spins it over like a champ, way better that the old one ever did.

[enuff_zed]

Change the starter. Mine died, the new one spins it over like a champ, way better that the old one ever did.

Agreed. Why spend days chasing an ethereal electrical issue until you’ve done the one hour starter swap?

[pvr]

On my list as well to do. Slow turning of starter

[axelleveau]

Alright, seems a new starter is on the list of things to do then. I spent some time cleaning and greasing all connections from battery to alternator today (not tested yet) but will keep an eye on the starter and change it when convenient
Thanks all for the help