grinding noise on first/cold start

[ftp19601960]

'02 Boxster with 65K miles. I have a "grinding", kind of, noise with each really cold start (attached p1.wav). I was thinking about delayed starter disengagement. I cleaned it up, re-greased gear and oiled solenoid. Testing starter outside car did not show any visible delay on pulling shaft in and out with direct battery power. The only piece which could be a problem in that starter, I guess, is its clutch. The clutch/bendix seems to be  not serviceable.  Starter cleaning did not help. 

[ftp19601960]

Second start in a minute looks much smoother p2.wav

[JuncoJones]

What about the battery? When you're doing a cold start, the battery has been idling / discharging for hours.

 

After the initial startup, the alternator will (slightly) recharge the battery, AND with the engine being warmer, startup should required less power than during a cold start.

Edited November 17, 2015 by JuncoJones

[ftp19601960]

I run it on weekends. I re-charge battery in between. Also, second start (p2.wav) is just after the first one (p1.wav) so battery charge cannot be part of it. Can it be something within engine? So after first start that is lubricated by oil and second start is smoother? Or that will be different sound? 

[JuncoJones]

OK. But, if the battery is not in good shape, charging it won't solve the shortage of amperage required during the startup.  The second startup will likely work better, as the engine has already spinned for a few seconds and is fully lubricated.

Both startups sound good to me, with the exception of #1 that it takes a few more cycles for the car to start. After the first ignition, the car should rev to 2k which happens on both cases.

 

if the car would be having some sort of oil pressure issues, I believe it would be noticeable. I'm more inclined in looking around the starter / battery area. Is this starter the original one? and what about the battery?

 

Boxtsers don't come with the oil pressure and volt-meter gauges, which would certainly help on these 2 different tests. I've upgraded my cluster with a 996 one, it was a nice project and really worth, it so I can have those 2 readings active at any given time.

Edited November 17, 2015 by JuncoJones

[cbonilla]

I had a similar problem on my '03 986S last year. Would only happen at the first start of the day, a momentary "grumble" that would quickly go away. We did some work on the Secondary Air Injection system to clear a CEL -- if I recall it was the SAI tank which was leaking. That seemed to have fixed the problem 90% of the time. I was told, by an independent Porsche shop which I trust and has inspired my confidence by doing good work and not looking to run up the bill, that some noise out of these systems is normal at this vintage. As this car is aging (it passed 100k miles this past weekend) this brought me peace of mind.

 

Your fears were much the same as mine (poor oil circulation?) or even worse  (the death throes of an IMS bearing?)  but I sleep easily now

 

 

Carlos

Edited April 20, 2016 by cbonilla

[kbrandsma]

Sounds like a classic tensioners issue to me.