Boxster 986 - quick 'whir' sound on start up
 

Just wondering if anyone has any suggestions, when I first turn the ignition over and the engine starts up there's a quick after sound, similar to a 'whir'. It only last like about half a second. A bit like something has a spin cycle which over laps the engine noise for a slight moment.

Any ideas what this is or if it's normal?

Most likely a sticking bendix drive mechanism on your starter motor. The fix would be removing the starter motor, cleaning and lubricating the sliding gear or bendix drive mechanism where needed, and reinstalling the starter.

The lubricated bendix drive will allow the starter drive gear to more quickly retract from the flywheel ring gear, as the engine "catches."

^^^^^^ this

I did this repair as described by jakeru. Not very difficult. You need a long extension for your ratchet because access to the lower bolt is from the front, beside the alternator.

I'm not very 'mechanical'. If I was to take it to my independent specialist, how much is likely to cost?

First, I agree with the others that's its probably the gear on the starter motor.

A shop will likely want to replace the starter rather than lube the gear.

I'd expect to pay around $300 for a starter from a shop + a few hours labor = $500-$600.

If I just leave it as is will that lead to any problems or will the noise just persist? It doesn't sound everytime.

Also the work you described to lube it, is this easy for a non-mechanical diy-er?

If it is the starter Bendix drive, the noise you hear is when it is grinding the teeth on the flywheel. Over time, this will ruin both the starter and the flywheel, and while the starter is relatively cheap, the flywheel costs about a grand, and cost about two grand to get at and change.

Depends on how "non-mechanical " you are. For me, it was a walk in the park, but I have all the necessary tools and a "hey, what could happen" attitude. ;) If you would like to give it a shot, it's not a terribly difficult DIY. Just read up on the procedure here in the forum and elsewhere and get your hands dirty! Hey, what can happen? :cool:

Here's a guide:
Porsche Boxster Starter Replacement - 986 / 987 (1997-08) - Pelican Parts Technical Article

It's literally step by step, showing which tools you need and which bolts you need to undo, all part by part. I've got the exact same problem as you and I'm going to do it as well, as I haven't done it before. I'm quite mechanically minded but this really doesn't seem hard at all.

If you look at that guide briefly, you'd think "Woah I can't do that?", but look at it again. Look at the photos and what it asks you to do. What wouldn't you be able to achieve in it? If you can use a ratchet, a screwdriver and a spanner, you can do this. Follow the guide and you can't go wrong :)

Luckily it's quite easy to reach as you can reach it from the top of your engine bay. I'd get in there bud! You'd have the satisfaction of fixing it yourself, and saving a lot of money.

I've only spent £300 on by Boxster S in my last year of ownership, because I do everything myself. That included a full set of brake discs, brake pads, exhaust gasket and a window regulator that snapped. The window regulator would have cost that alone, let alone the labour to fit it. If I took it to a garage whenever I wanted to do something to it, I'd be broke.

Go for it :)

Note that the lower bolt is more easily accessed through the front cover, behind the seats, with a long extension on your ratchet.:)

Good point :) thanks for reminding too, as I need to clean mine. Hate the donkey noise it makes sometimes!

What would you guys do to clean it? Anything to avoid?

I just took it apart and cleaned it with a battery operated detailer brush ( a toothbrush will do) Probably used some brake cleaner or similar. I think I used lithium grease to lube it. Someone else might have a better suggestion. Been working great ever since, about 2 years ago.