Strange ratling engine sound, help finding it

[wawa]

Update to let you all know, the noise was from bad alternator bearing. The free pulley was not free anymore and bearing were making noise. All gone now, yeee!

Later
Chris



I hear a strange ratling engine sound from my 2000 Boxster S

At first I though it was a belt tensioner, the lower one. It was loose, so I change it, but sound is still there.

Can you help finding it?

Here is a youtube video


Stange sound, 2000 Boxster S - YouTube

Thanks
Chris

[Steve Tinker]

Thats not nice - is the noise still there if you run the engine with the accessory belt removed ?

[wawa]

Doh! Why I did not think of that. I will try it tomorow and report back.

Later
Chris

[epapp]

it sounds like a bearing that is about to fail. most likely in one of the accessory pulleys.

[wawa]

Well the sound is not there when the belt is out, so it's an accessories, but which one?

There is a tiny bit of play from the power steering and a bit from the upper tensioner but nothing obvious. Any trick to help out finding the right accessorie?

Later
Chris

[Jager]

Water pump?? You can spin it with the belt off and feel/hear if there are any issues.

[thom4782]

Jager might be spot on. How many miles since you last changed the water pump? If over 60K, it might be suspect.
Do you notice any dried crud in the water pump area (lower passenger side of the engine) that suggest a small fluid leak from a worn bearing? If you put the belt back on and leave the access cover off, can you get a better handle directionally tell where the noise be coming from?

BTW: If you do run the engine with the belt on and cover off, make sure you don't have any loose clothing on that could get caught and remember to keep yourself clear.

[wawa]

I tried to feel every pulley and also listen from where it's coming but I can not for sure tell which one. But from listenning at some video on Youtube, I found a couple with bad water pump that sound like mine, so I guest thats it.

I'll bring it to my machanic and he'll find out. He is 300km away, hope it's gonna be ok.
I dont know if it ever been change.

Later
Chris

[thom4782]

No one closer eh?

My WP started to make a low volume squeal that I only heard below 2000 RPMs. Twenty miles later the pulley fell of the shaft. $1200 later the car was back on the road with a new WP, fresh coolant, and a low temperature theromostat.

[Steve Tinker]

Chris - are you sure you want to drive 300 km to your mechanic with a faulty coolant pump ??
The concequencies could be, like, serious if it fails....

[wawa]

There is no mechanic I trust enough around. Beside, the water pump still work good. It's just a bearing and I'm not even sure it's the WP one. My best option, leave it to the professionnel. If something goes bad while driving there, I'll put it on a flat bed.

Later
Chris

[Frodo]

If you're gonna do that, keep alert for leakage of coolant. You can see it and you can smell it. If the WP totally goes, you can end up with little pieces of the impeller blades floating around in the system---not a good thing.

Do you know if/when the pump's been replaced? I don't know what your mileage is, but if it's the original pump it's way past due for changing. (For a 2000 model, that's actually true regardless of your mileage.) If it's not your daily driver and you can get around without it for a spell, you could consider changing it yourself---there's several DIY write-ups on the procedure, and it's a doable thing. I'm far from being a seasoned mechanic, but from what I'm hearing, I'm with SteveTinker---I'm not altogether sure you'll make it 300 km.

[wawa]

The car have nearly 100k mile (158k km) and I dont know if it's ever been change.
DIY, I'm looking at it. It look simple enough, it's just the bleeding part I'm a little affraid of.

But I need to be sure it's the WP, I have change too many good parts before from wrong diagnosis. I'll jack the car and inspect it more from under.

Later
Chris

[Nimbus117]

You need a mechanics stethoscope, essential for identifying problems like this:

Lisle 52500 Mechanic's Stethoscope : Amazon.com : Automotive

[wawa]

Update in first post

Chris

[pedot99boxster]

just replaced my water pump last june'13, it was making some grinding noise and some dried gunk on the underneath hoses , replaced the thermostat also and the hoses,
it's pretty easy,
check out my posted video on youtube on bad grinding water pump type in "986 water pump"