tenshun

Hey guys and gals,
I've been noticing more and more lately that I hear a distinct "whirring" noise coming from the engine bay. Since it makes the noise whenever the engine is running I am afraid it might be a pulley bearing going out. Has anyone had a similar problem? Mine is an 08 xB and doesn't have any engine modifications as of yet so I feel like this is not a typical problem for a car with 80000 miles.

Are there any other possibilities that this noise could be? I tried using my mechanic's stethoscope to pinpoint the sounds but has no luck. The only thing I noticed is that it seemed to get louder the further back towards the firewall I went.

How bad of a problem would it be if the pulley seized up? So far I haven't noticed any change in my car's performance. Funds are tight right now so I need to know how urgent I should get this checked out by a mechanic and if it's something I can do myself (I'm fairly handy).

Your help is appreciated in advance.

DEXBOX

how's your serpentine belt looking?if it seems dry or cracking try prestone belt dressing.it's more of a process of elimination,it would not hurt either.

goldtoaster

It might be your serpentine belt. My 08 is at 65000 and I just changed my belt.

Shadezz

iTrader: (1)

Glad you got yours figured out!! Was it a bad belt Gold Toaster?

tenshun

I'll have my belt checked out then. I figured it was a pulley/bearing since it was more of a whirring/humming sound than a squeak or chirp (which I tend to associate more with a bad belt. Also, doesn't the xB2 have an auto belt tensioner that would eliminate loose belt issues? I'm not well versed in this area of mechanics so your help is appreciated.

tenshun

Hey guys-
So I've continued to drive the xB and I've noticed the "whirring" sound is getting louder and sounds more metallic. I've inspected the belt and it doesn't appear to be cracked or bad. Plus, I've put a stethoscope down in there and I noticed that the sound was loudest by the belt tensioner mechanism.

So, given the little information I have, I'm assuming that it's probably a bearing going out on the tensioner - unless someone else has another viable explanation which are always welcome. Given that my toaster is sitting at around 87,000 miles I also assume that this is possibility based on age and use.

Now lies my next question. Does anyone know the exact part # for the tensioner? I've tried several different oem sites and always seem to come up with a different part # each time with prices ranging from $125 to $250 (seems like a big range considering they're all just OEM replacement parts).
Also, would it be worth it while I'm replacing the tensioner to go ahead and get a new belt (even though the old one isn't in bad shape) and possibly throw on a NST crank pulley while I'm in there?
I haven't been able to find a good DIY post on doing this specifically on a xB.

Any help is greatly appreciated in advance. Cheers!

ttircuit

I do mechanic work. And I would recommend putting a new belt on. I just see no point in taking an older belt off and not spending the $20-30 to just go ahead and slap a new one on. Also make sure if NST pulley is an undersized pulley (not sure about that) make sure you get a belt that it calls for.

oreoremix42

agree with the above^^

OP my car just had the same sound and mine is a 08 with the exact same mileage and I found out it was my water pump. Check there!!!!

tenshun

So was the entire pump going bad or was it just a bad bearing on the pulley side of it? The reason I ask is because it doesn't seem to be affecting the performance of my pump since there haven't been any overheating issues at all (and its the middle of HOT season here in TX). Is there any way to check if it is indeed my water pump crapping out?

So I'm sure I'll replace the belt and probably get the NST crank pulley just for kicks and giggles. The only thing keeping me from pulling the trigger is not really knowing for sure what it wrong. I mean, I'd hate to drop $200 on a new belt tensioner, replace it, and then start up the engine only to hear the same noise again, ya know?

Perhaps I should just bite the bullet and take it to a shop for a complete diagnostic on what the issue is. I just feel like those places end up screwing me over 90% of the time. I don't know. I appreciate y'alls opinions though. Hope to see a resolution to this soon.

xbscion

Why not just remove the belt and then turn the pulleys by hand? If they are making that much noise you should be able to feel some play or roughness in the pulleys of either the w/p or tensioner.

ttircuit

^^ agree with that. You should be able to feel roughness.

tenshun

Well, I think I made some progress tonight. I got in there and took the belt off (which, btw, was easy enough to do by myself) and hand checked all the pulleys - minus the crank pulley obviously.
Aaaaaaaand I couldn't really tell much. All the pulleys themselves seemed to spin freely and smoothly. There was a tiny bit of play on the belt tensioner but from what I could tell, it was more in the spring action than in the actual pulley bearing.

So, next step I turned everything off and was as quiet as possible while I spun each pulley as fast as my little hands could in such a tight spot. Obviously I was able to spin them as fast as if the engine were actually running, but I DID NOTICE that when I spun the water pump pulley that I got a similar noise as when the engine is on. Everything else seemed to sound ok.

This leads me to believe that what I've been hearing is the water pump, as was suggested previously. I've also always had the notorious water pump issue where it sprays pink coolant on the hood liner, however I've been fine with just topping off the coolant every couple of months and I've never had any kind of issues with overheating, even driving it daily here in the 110 humid heat of Austin.

So I guess my next step is going to be to replace the pump and hopefully knock out two issues at once (no more leaking spray, and no more terrible sounds). If I do it and the sound is STILL there, then I guess I'll move on to replacing the tensioner because that's the only other possibility I can think of.

Next question then, is the water pump a DIY project? I've never replaced one before but I have a decent tool set and am pretty handy. If I can save the money and replace the pump myself I will save a TON of money (already priced a new pump at O'Reillys for $55 with lifetime warranty).

Thanks again guys for all yall's help.

pyroman131

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Geigle

Hey I have a 05 td rs1. I am getting a high humm from the serpentine belt area and I know that it is more than likely a bearing going out in the water pump, alternator or one of the other pulleys. Scoped it and it sounds like the alternator but I am worried I will drop the two fifty on the alternator and it will end up being the water pump lmao how can you be sure what pump/bearing is going bad? Also did the new pump fix your issue?