idler pulley/hydraulic tension/tensioner pulley..im lost!

Need to replace my idler pulley and tensioner pulley due to an annoying high pitched sound I get at idle.
Does the hydraulic tensioner cause a noise too? All belts are in great condition so i'm good there.
By the way would I be taking a huge risk going on a 300mi road trip (approx. 600 roundtrip) with bad pulleys and whatnot? Thats probably a stupid question.
Sorry for all the questions, i'm learning soo much from reading on this forum
Anyway thanks in advance.

See sig. It should've popped up when you signed up on E46Fanatics. But if it didn't, use your eyes to look below. use your finger to click it.

If the bad pulleys fail or cause a belt to snap you can have major overheating problems on a road trip.

I do tensioners when I do pulleys out of habit, but I don't know that you have to.

I've found with BMWs it's better to fix small things like this before they totally fail and become big headaches.

Originally Posted by CaptainOversteer

If the bad pulleys fail or cause a belt to snap you can have major overheating problems on a road trip.

I do tensioners when I do pulleys out of habit, but I don't know that you have to.

I've found with BMWs it's better to fix small things like this before they totally fail and become big headaches.

Has DMAX already proposed to you? Cause if not, I'd like to.

No, Mango, it was just that one night...and nothing against the Capt., but really wasn't my cup of tea!

OP...do all three pulleys...find out which tensioners you have first (mirror and good led flashlight)...get the right pulleys.

FYI my mechanical tensioner is still good and undoubtedly original...I replaced my hydraulic tensioner when I first came to fanatics coz 'they' scared me into doing it, but don't think you have to. The pulleys are really doing most of the work I think...spinning around a billion times. The tensioner pretty much just tensions, so I don't think it wears down particularly fast. Of course, it won't hurt to change it, but I don't think you 'have' to.

Originally Posted by E46Mango

Has DMAX already proposed to you? Cause if not, I'd like to.

I'll start the bidding at $50

Originally Posted by Koffinb

Need to replace my idler pulley and tensioner pulley due to an annoying high pitched sound I get at idle.
Does the hydraulic tensioner cause a noise too? All belts are in great condition so i'm good there.

Pulleys can develop play and yet work without causing any noise. Most of the time - when you have a high pitched noise at idle - its the mechanical tensioner (what I guess you have). Its the noise problem why I have gone from mechanical to hydraulic tensioner on my E39 and E46. The hydraulic tensioners work just fine. If youre not sure if its the tensioner - pour some water over a pulley while engine is running. If noise is still there - go for next pulley/tensioner.

What you should do is remove the fan, remove the belts (water pump belt and AC belt) and check ALL pulleys. Spin them and see if they spin for a long time or stop quickly. If they stop quickly the bearing is bad. Also pull/push the pulleys along the axis - if theres any play - bearing is bad.

Check the belt on the inside where the ribs are. See if there are any cracks.

I change the water pumps on all my cars every 100.000km. When I do I usually change all my pulleys and the belts as well. This way - you have another 100.000 carefree kilometers.

If you only change one pulley - how do you know when the next one is due?

Um, southpark...if the pulley spins freely it's bad. If it stops in a turn or two it's good.

I suspect you've been replacing a lot of pulleys...or just mis-typed!

Sorry - english is not my first language (its my third language). I might have used the wrong words to discribe this.

Anyway - what I meant is that a pulley should spin smooth and steady. It shouldnt move on its axis or make rattling noises while it spins. But then again - if a pulley stops in a turn or two - its either brand new or totally out of order - judging by this you would have to replace pulleys all the time, too

A good but old/used pulley can spin freely - whilst not having any play at all. In a brand new pulley there is a lot of sticky grease on the bearing that inhibits the spin - thats why it stops in a turn or two. That doesnt happen if you have a good pulley thats been in use for 50.000 miles. But again - I have already had cases in which a pulley went bad - destroyed the belt and caused a mess in my engine compartment - the car only had 30.000 miles and was only 3 years old

So - yeah - I change pulleys in 100.000km cycles and when I do I change all of them...

Originally Posted by Koffinb

Need to replace my idler pulley and tensioner pulley due to an annoying high pitched sound I get at idle.
Does the hydraulic tensioner cause a noise too? All belts are in great condition so i'm good there.
By the way would I be taking a huge risk going on a 300mi road trip (approx. 600 roundtrip) with bad pulleys and whatnot? Thats probably a stupid question.
Sorry for all the questions, i'm learning soo much from reading on this forum
Anyway thanks in advance.

Dayco part numbers for E46 pullies:
for hydraulic tensioner: 89046
for mechanical tensioner: 89133
Idler pulley: 89089

As Doug said, use flashlight +mirror/small phone camera to inspect what tensioners you have. My understanding is (someone correct me if I'm wrong) three combinations are possible:
mechanical tensioners for both water pump/alternator AND A/C belt
Mechanical for A/C, hydraulic for WP/alt.
hydraulic for both A/C belt AND WP/alt.
I've never heard that someone had hydraulic for A/C and mechanical for WP/alt. but I don't exclude that possibility.
EXAMPLE: If you have two mechanical tensioners, you would need 2 x 89133 and 1 x 89089

If you don't have automatic, it is literally 15 min. job to inspect your pullies, even with removing electric fan to give you more room. Don't guesstimate its condition, it is easy enough to check and it is cheap enough to replace...it's a quick DIY, too. I am not saying you will have problems with pullies on a 600 mile trip...but how often do you make such a long trips. Probably not that much often. So if it's time to replace them, why not do it before that kind of a trip.

Originally Posted by Koffinb

Need to replace my idler pulley and tensioner pulley due to an annoying high pitched sound I get at idle.
Does the hydraulic tensioner cause a noise too? All belts are in great condition so i'm good there.
By the way would I be taking a huge risk going on a 300mi road trip (approx. 600 roundtrip) with bad pulleys and whatnot? Thats probably a stupid question.
Sorry for all the questions, i'm learning soo much from reading on this forum
Anyway thanks in advance.

Once you follow the advice above and grab some replacement pulleys, do you have a Torx set? i have mechanical tensioners, and they require a T50 to remove the bolt holding the pulley to the tensioner.

I replaced my A/C pulley the other day with the Dayco one in my sig. From start to finish, took me less than 5 minutes.

ok, how many idler pulleys are there??

One. It's next to the alternator.

http://www.turnermotorsport.com/p-16...-steering.aspx

this one right?

or is it this one??

http://www.turnermotorsport.com/p-20...-steering.aspx

The first one is the idler pulley. There is one of them, next to the alternator. The second one is the pulley that goes on the tensioner for main belt that spins the pumps and the alternator.

thanks!

The first link is your idler/deflection pulley. The second one is for your tensioner...which I presume means the hydraulic one.

Idler has that funny pin sticking out of it...it is available at Autozone as a Dayco/duralast pulley...and is made by INA, which is the OE maker for us. Call Autozone and get its price on all three pulleys...might save you $ in part and in shipping.

do they all make the same noise or just one?

If one pulley is bad the others are or will be soon. They all have spun just the same amount.