fpena944

Ever since I've had my car back from the water pump replacement I now hear a screech or scraping sound that happens about 1-2 seconds after a cold start.

It doesn't sound like the engine or a belt but more like a fan starting up. I was thinking it might be the emissions fan but then I do hear that whirring away once the car is running after a cold start. Could it be still making that noise upon startup?

If it's not clear I'll try to record the sound tomorrow morning. I know this type of troubleshooting on the web is tough without a sound clip because my description is open to interpretation. But anyone heard or encountered anything similar? Again it only happens during my first start of the morning. Even when parked in the garage at work all day it doesn't happen in the afternoon. I checked the oil level and we're two bars from the top so good there.

Any ideas?

dporto

Belt Tensioners/Idler pulleys?

Macster

Well, if I had to make a guess I'd offer up it is a dragging over run clutch on the starter.

For no rhyme or reason I've had this come and go with my Boxster so I can't offer any guidance other than be sure you are not prolonging holding the ignition in the start position any longer than necessary.

If the noise persists and other explanations have been eliminated it could be the starter could be removed and the splines upon which the pinion gear slide upon cleaned and greased or treated with whatever lubrication is intended for that application. (Years ago I just used a heavy/high temp grease but I have no idea what's used nowadays.)

The over run clutch is probably not available separately from Porsche, but someone has probably found something that works but I have no link to provide.

If the starter needs rebuilding if you live in an area that is large enough to support a Porsche dealer you probably have a starter rebuilder handy. Someone who specializes in just starter rebuilds and has access to all equipment and parts.

You can check with the Porsche dealer, BMW dealer, M-B dealer so see who they refer starter rebuilds to. (My local Porsche shop has a starter specialist they recommend be used if one doesn't want to pay the freight to replace a starter with a new one.)

But post a good video/audio clip. It could be the secondary air injection pump at least at start up. You could possibly eliminate this by pulling the fuse and seeing if the air injection pump doesn't come on when you start the car under the same conditions as when the noise appears and the noise is absent.

No need to run the engine any longer once you have confirmed the noise is absent or present. Shut 'er down and install the fuse.

zak996

I'd start by making sure the drive belt is on correctly and not rubbing on a pulley. Its a quick job to take it off to feel for play in any of the tensioners or pulleys. That way you can rule that out easily in 10 minutes.

mharrison

Remove the belt and see if it makes the same noise on startup. If not, it's a belt driven item.

Troubleshooting is all about breaking a problem down into manageable pieces.

fpena944

Thanks for the recommendations! The dealer was the one who replaced my water pump recently so if it got to the point where the starter is the culprit I'll probably just take it back to them and have them replace it. Might be more expensive but I use this car daily so want to try and keep downtime to a minimum.

All good ideas. What stumps me though is that it only happens when cold. But maybe the belt is storing some residual heat which keeps it from slipping? Don't know but I'll look at it this evening and record a clip tomorrow morning if I can't figure it out.

Appreciate the input everyone!

Barn996

I'll take air pump for $800 Alex...

Imo000

It's the starter bendix sticking a bit. Other than the noise, it will not harm anything. The bendix need a bit of cleaning (probably has some clutch dust in it) and some greasing up.......and that's it. The noise might go away on it's own too.

fpena944

Tried to record a sound clip just a few moments ago but of course it didn't do it!

The car has been cooling off for about 4 hours but I guess that wasn't long enough. I'll try again in the morning and see what happens.

Howaboutthat

Crazy screeching sound? That's the harmless starter-related thing many of us have encountered.

Ahsai

If yours sounds like this, that's your starter. Need to relube or replace.

fpena944

Got the sound clip recorded this morning:


Happens at the 4 second mark. Any ideas?

fpena944

It does sound very similar. I just posted my clip.

So now the question, how to relube and how to determine if replacement is needed?

FastM96

Starter for sure. Do-it-yourself type could remove and bring to a rebuild shop for service or just replace with new/rebuilt starter. Indy or dealer will probably just want to replace it. Either way, no big deal.

Macster

Agree with FastM96. Starter. But not that bad either. 'course, it will either get worse, or possibly go away. (The noise from my Boxster's starter has gone away.)

Up to you of course how you want to deal with this. I can certainly understand when one is relying upon the car for his sole transportation needs having the starter replaced.

The part is ordered and once in the car dropped off and the starter replaced and the car back on the road in practically no time.