Horrid start-up noise - 986 Forum - The Community for Porsche Boxster & Cayman Owners

pothole · 09-15-2011, 01:04 PM

It gives me much joy to report my '97 2.5 has developed a lovely new start up noise. I've attached a couple of sound files - one of a start up with the new noise and one of a normal sounding start up taken a moment after the noisy start up.

The sound of the noisy start up is a little higher pitched in real life than the sound recording and seems an awful lot like a noisy chain running over guides - you can hear something catch or lift at the 5-6 second mark and then the noise completely disappears.

I've only heard the noise three times and it has only done it when warm - but it has never happen before today and I only had one completely cold start.

*NOTE: YOU WILL NEED TO RENAME THE FILE EXTENSION TO ".m4a"
This forum won't accept file uploads with that extension to I changed the files to ".doc"

My guess is that one of the hydraulic chain tensioners is taking a while to kick in. Having said that, I'm not sure it should ever sound like that, even before the oil pressure has had a chance to build.

Thoughts? Thanks.

EDIT: youtube links added:
http://www.youtube.com/watch?v=QTy8jvx0VrY (bad noise)
http://www.youtube.com/watch?v=oCEYS_VFoKY (normal start up a few moments later)

ubii · 09-15-2011, 01:50 PM

Ouch, that sounds pretty nasty, I would get that looked at as soon as possible. I recently had my chain tensioner paddles replaced, since my car was already in the shop getting an IMS retrofit kit, clutch, and RMS installed. About a week or two before I took it in, it developed a somewhat similar sound upon cold starts, though not as profound and only lasting about 1-1.5 seconds. Here is photo of the chain tensioner paddles that were replaced, as you can see the two inner paddles on both banks (the two on the left side of the photo) were pretty ate up and I was told that this was the cause of the noise I heard. The link below, is to a thread I started prior to taking it into the shop, regarding my concerns of a potential IMS failure, after discovering metal flakes in my oil filter.

Metal Flakes Found in Oil Filter

pothole · 09-15-2011, 02:11 PM

Yeah, the sound was recorded in my garage and the reverb / wall reflections make it sound pretty bad. Don't get me wrong, it doesn't sound great out in the open, but it doesn't quite as gruesome. Also, it sounds completely normal after whatever it is that's catches or kicks in. It will need looking at, was just hoping someone may have experience something similar.

Can the hydraulic chain tensioners be changed without pulling the engine?

ubii · 09-15-2011, 02:36 PM

Quote:

Originally Posted by pothole

Yeah, the sound was recorded in my garage and the reverb / wall reflections make it sound pretty bad. Don't get me wrong, it doesn't sound great out in the open, but it doesn't quite as gruesome. Also, it sounds completely normal after whatever it is that's catches or kicks in. It will need looking at, was just hoping someone may have experience something similar.

Can the hydraulic chain tensioners be changed without pulling the engine?

According to the following Pelican Parts technical article (see link below), you should be able to replace the paddles without removing the engine. Here is a quote from that article:

"All of the tasks illustrated here should be able to be performed on the engine while still installed in the car, although clearance is tight and it's somewhat difficult to work under the car."

http://www.pelicanparts.com/techarticles/Boxster_Tech/16-ENGINE-Camshaft_Swap_and_Chain_Tensioner/16-ENGINE-Camshaft_Swap_and_Chain_Tensioner.htm

I think that they decided to remove my engine, because they initially thought that the chain guides (99610517552 and 99610517353) would also need to be replaced. That ended up not being the case, as only the paddles (99610525300) needed replacing.

pothole · 09-15-2011, 02:44 PM

OK, thanks.

And for easier listening, I uploaded some youtube videos of the noise.

http://www.youtube.com/watch?v=QTy8jvx0VrY (bad noise)
http://www.youtube.com/watch?v=oCEYS_VFoKY (normal start up a few moments later)

Frodo · 09-15-2011, 04:59 PM

Wow, that first vid sounds like someone firing up the John Deere to start the harvest!

pothole · 09-15-2011, 05:08 PM

It does

. But is it the chain? Could it be something else? It completely disappears after a few seconds...

coreseller · 09-16-2011, 03:20 AM

Possible shot in the dark......it wouldn't be the bendix / starter solenoid sticking or in any way starter motor related? The abrupt absence of the noise after a few seconds of racket makes me think the starter gear could be retracting......just a thought.

pothole · 09-16-2011, 03:37 AM

Yeah that has crossed my mind due to the ay the noise abruptly stops. It just sounds very "chainy"...

Frodo · 09-16-2011, 04:57 AM

Quote:

Originally Posted by pothole

It does

. But is it the chain? Could it be something else? It completely disappears after a few seconds...

Don't know the answer to your question, but I think mine does the same thing very briefly when I start her. It's a little hard to characterize, since it lasts only like a second. I assumed it was no big deal...

pothole · 09-16-2011, 05:02 AM

Yup, mine has always been a bit noisy on start - but only very briefly, so hard to know if this is a completely new noise or the old noise lasting five seconds rather than a second or so. But I think it's a new noise.

jbs986 · 09-16-2011, 06:49 AM

Quote:

Originally Posted by coreseller

Possible shot in the dark......it wouldn't be the bendix / starter solenoid sticking or in any way starter motor related? The abrupt absence of the noise after a few seconds of racket makes me think the starter gear could be retracting......just a thought.

Mine made a shereking sound when I first started it and would stop,noise lasted maybe 2 or 3 seconds. I replaced the starter and now it is fine.

pothole · 09-16-2011, 10:44 AM

Found a youtube video posted by a forum member here - this is exactly what my car has occasionally sounded like on a cold start. I think the new longer noise is the same noise but running longer and from a warm start rather than a cold start. Anyway, here's the video of the other guy's car:

http://www.youtube.com/watch?v=zyYaAmZ9dsY

coreseller · 09-16-2011, 12:26 PM

To eliminate the starter being the culprit, you could simply bump-start the car to see if it still makes the noise....just an idea.

pothole · 09-16-2011, 12:51 PM

At this stage I am pretty sure it's not the starter. Pretty sure it's a chain tensioner.

What I am currently looking into what's involved with changing the tensioners and if they can be reconned.

pothole · 02-01-2012, 04:53 PM

Just in case anyone is interested, this turned out to be the starter motor sticking. Actually, it wasn't the starter motor really sticking, it was the switch in the ignition barrel getting stuck and causing the starter motor in turn to stick.

Scott Schreiner · 02-01-2012, 05:57 PM

Just went through this with my Boxster as well. The starter really does make a horrible noise when it stays engaged to the flywheel after the engine is spinning.

In addition to the sticking starter, I narrowed it down to the ignition barrel because it wouldn't release the key when I turned the car off or turn off the electrical signal once the key was removed.

Lucky for you, the replacement parts are a better design and you should be in the clear now as long as you didn't significantly shorten the life of your starter by over-spinning it. Although thats unlikely.

-Scott

fivepointnine · 02-01-2012, 06:06 PM

thanks for the update!

coreseller · 02-01-2012, 06:16 PM

Nailed it!! Arf Arf !!

pothole · 02-01-2012, 06:33 PM

Quote:

Originally Posted by Scott Schreiner

Just went through this with my Boxster as well. The starter really does make a horrible noise when it stays engaged to the flywheel after the engine is spinning.

In addition to the sticking starter, I narrowed it down to the ignition barrel because it wouldn't release the key when I turned the car off or turn off the electrical signal once the key was removed.

Lucky for you, the replacement parts are a better design and you should be in the clear now as long as you didn't significantly shorten the life of your starter by over-spinning it. Although thats unlikely.

-Scott

yup, mine is exactly the same - difficulty getting the key in and out, some items like the stereo occasionally remaining powered once the key is removed. Thank god Porsche pinched most of this stuff from VW / Audi so there's a source of reasonably priced parts!