911Jetta

+++ The problem was traced to a bolt spacer that slipped within the power steering assembly (see post #32 for details). Below is my journey towards discovering the problem...with lots of extra DIY jobs thrown in as I finally discover the problem... +++


I was idling at a stoplight this weekend when I suddenly heard a brief metallic clanging, scraping noise. It lasted for a long second and then stopped. The light turned green and all was fine for about another block. The noise came back and was continuous for as long as the engine was on. I was able to pull into a parking lot and try to diagnose what was going on. I was able to get it home and tucked away in the garage, but now I need to figure out if I can fix this...or, drive it to a shop so it can be fixed...or, call a tow truck?

All of this is new to me...I need help! (I searched to get some background info.)

Here's what I noticed:
- loud, metallic, scraping, grinding noise coming from the engine fan area.
- the sound is always present when the engine is running.
- the noise stays at a constant frequency, as in, it doesn't get faster or louder with revs. It's like something is grinding away at 1,000 RPM.
- it was day time, so didn't have lights on (so didn't notice dim lights)
- didn't have radio face plate on, so didn't notice any effect on the radio volume, etc.
- no dash lights came on.
- no effect to engine temp, pressure, etc.
- belt tension seemed find and I found nothing loose or broken in the engine bay.
- about a week ago the car experienced one long, hard start. It seemed like it took 5 seconds to start....it cranked and cranked and then started. Ever since, it has started fine. Starts fine now also.

If it's an alternator problem:
- can I fix this with some simple tools (and a bearing puller)?
- should I take it to the shop because it's too much of a hassle? I don't want to spend 10 hours as a newbie fixing this...4 hours is OK though?
- can I drive it to a shop (25 miles)?

Thanks in advance for any help you can give me with this problem!

http://www.youtube.com/watch?v=7WnC__0_yAk

http://www.youtube.com/watch?v=urJ2hKBPhwY

Rocket Rob

My car did that. It was a bad fan bearing. Can you drive the car? Yes but you are scraping the fan against the housing so you want to minimize it.

What tools do you need? You need to remove the fan belts, triple square wrench, 10mm socket, 5mm allen wrench and a puller. The way I did it, I removed the fan belts and alternator. Put the assembly on the bench to remove the fan and bearing. I used a press to remove the bearing from the fan but you may be able to do it with a bench vise.

Time estimate for a newbie? 2-3 hours. Less than 1 hour to remove the alternator, 30 minutes to remove the fan/bearing and install the new one. 1 hour to reinstall.

Be sure to hook up the alternator wires properly. Noting where the blue and brown wires go. Don't reverse them. Ask me how I know......

crg53

Yes, I agree with Rob, sounds like a failing bearing which causes the fan to hit the fan housing.

mdowell

I had the same issue. You could see the scrape marks where the blades hit the housing. One of my blades had a crack in it. If that's the problem, fix sooner rather than later.

- Fan blade comes loose and causes all kinds of anarchy
- Metal dust gets sucked in to the intake

I bought a used fan and housing for $250 (and replaced the alternator while I was in there for another $95)

911Jetta

Rob, (et al)
Thank you so much for the clear explanation. That goes a long way toward me being able to build up the courage to do this…though I’m still thinking about driving it to the shop?

Now that you’ve helped me diagnose what’s wrong, I’ve been reading your helpful steps and comparing it to the instructions on p-car.com. Hope it’s about 99% of what I need to do this…

Wow, if I can do this, I’m really tearing into the heart of this monster! A little scary thinking I’d have to remove the A/C compressor/belt and take the fan out?

What are the service intervals for the belts…I’m coming up on a 15,000 mile service (2,000 miles) and need to research if they would be replaced anyway. Wanted to do my own first time valve adjustment, but maybe the shop should do the whole thing since this problem cropped up? Plus I need to order the 12 point allen tool before I can even get started.


Should I follow the steps in this DIY?
How to replace your V- belt (Porsche 993 DIY)
http://p-car.com/diy/vbelt/

How to remove the alternator (Porsche 993 DIY)
http://p-car.com/diy/alternator/alternator.html

Looks like I’ll need to order this part? (yes/no)
Special Porsche 12 point allen tool part#999 571 052 02
(can I find a suitable substitute at a local hardware store?)

BTW- is this what you mean when you refer to a triple square wrench?

Thanks again!

Rocket Rob

The triple square is a special wrench needed to hold the alternator shaft stationary while you loosen the pulley nut. You should have one in your emergency tool kit. I purchased a set of triple square sockets at my local PepBoys. The tool looks similar to a torx driver but has 12 points instead of 6.



How often should the belts be changed? I change mine every 30K mile service. I also replaced them while I had them off changing the bearing.

911Jetta

Thanks for the tool kit mention, will look when I get home. (Laker, thanks also for your message!) That means I can start taking things off soon.

Called the shop, they said if it's a bad bearing the job is listed at 3.5 hours service (@ $80/hr) and the bearing (and what it sits on - maybe they said race or hub...too much in my head right now) is $185.

$500 to fix it... plus getting it there. (Would probably feel better about towing it.)

I quickly found this video: http://www.youtube.com/watch?v=pxAuGnDtKAs

That gave me some courage, so I'm thinking....

Screw it, there's so much help on this forum, some help in my neighborhood, and maybe a couple more good videos out there...I might as well try it! I'm going to do some more research but I think it's time to man-up and do it! Plus my dad is coming into town in a few days, sounds like a great bonding experience?

I knew I cursed myself a couple weeks ago when I responded to an RS Single Belt thread...
With the money I MIGHT save doing it myself...I might be able to slip one on without the wife knowing!

dfinnegan

You can do this.

Keep the pulley and shim parts together with a zip tie, or string. As you take them off, drop them on the string in the correct order. Then tie until you reassemble. Also make note of the wire connections.

I pulled the bearings with a simple 3-prong pulley puller that I bought at Sears, or an auto parts store.

With input from this form, I'm sure that you can do it.

Also, you have a PM.

Cheers,
Dave

Porsche917K

I wouldn't drive or run it anymore. The fan is magnesium which means that its already brittle given its age. I have seen several fans that have had contact with the shroud and the fins start to splay over time. These things rotate at a pretty high RPM. I wouldn't chance it personally. Not a cheap or easy to find part.

911Jetta

I have the tool! (now I understand why a complete tool kit is so important)

Was able to get the fan out in 1 1/2 hrs. Wow, what a feeling. Can't thank you guys enough. There's no way I could have do this without your encouragement. We'll see if I can get it back together...

I'll going over to a friend's Haus with a bench vise...to separate the fan housing. But I'm kinda stuck as to what to do next or even what to order? I know, I'm a mess. The bonus at this point is that even if I had to get it towed to the shop...it would be less labor hours with the fan out!

If you saw the video above, I hoping this is a bad fan bearing?
With the fan out, but alt. and fan housing still together, everything still spins really freely. Should that be the case, or would the noise (contact) appear if I spun it at 1,000 RPM (something I can't get close to reaching just spinning by hand)?

So I'll separate the fan and housing and do some more research.


Everyone loves pics!

911Jetta

Fan spins nicely, but I hear some chirping...
http://www.youtube.com/watch?v=oQFhXmMfyJA

hawk911

hell, why not paint it why you're in there? What's with all you people???? I though we were friends! Spend Udo's money!

dfinnegan

That's funny!

wolfgang1

I had a similar problem... I ended up replacing the fan itself. After careful inspection, the fan was cracked and one of the blades was "longer" as a result. I bought a replacement fan at sunset... much cheaper than any place else.

Rocket Rob

The bearings should be silent and glass smooth. Can you wobble the fan? Is there any slop? I suspect there is.