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View Full Version : Anyone one have this noise and symptom?


neubath
08-20-2013, 01:15 AM
So about a year ago I threw my serpentine belt, at the time I replaced the two freewheeling pulleys and the belt tensioner. A few weeks ago I threw the belt again, had it towed and they changed the belt and sent me on my way, saying there isn't anything wrong that they could tell. But every now and then right after restart, particularly when it was warm I would hear a screech just as it was firing up. Still I saw no pulleys that were acting up. I did see a little jumpiness to the belt tensioner, but minor. So now I have a total new noise, best I can describe it, it sounds like when you throw tiny rocks into a metal fan, it starts on cold start and fades away when it warms up. I cant tell exactly where its coming from, kind of sound like it may be coming from the front of the engine somewhere. I'm wondering if its the newer belt tensioner, the alternator decoupler, or the fan itself. Does the alternator wear out and seize like an when an electric motor does when the brushes wear out?? It may be totally unrelated, but I know the other day I was driving and completely lost boost, I changed all of the fat intercooler lines, and that seemed to make it better. I also changed the turbo resonator to the solid aluminum one. The engine seems to run okay, maybe a tad bit more vibration then usual, and I do have a slight idle rpm variation. But I'm not sure if that's normal. The harmonic balancer seems solid, I cant move it anyway. I had the engine bay cleaned yesterday, on a cold engine, I'm hoping that didn't do it...I'm perplexed as hell...Oh that's right, I own a Sprinter! Anyone have any thoughts?:thinking:

2005 Dodge Sprinter
122K

pfflyer
08-20-2013, 03:18 AM
Did you install an OEM tensioner? Don't know about the sound you are describing but not long after I had installed a non OEM tensioner on my 02 my belt started chirping at start up then gradually got worse but was sporadic. Long story short my alternator pulley sheared off a couple thousand miles later. Saw posts here about aftermarket tensioners not being to spec. Supplier of tensioners blames these failures on aftermarket or cheaper pulley clutch on the alternator. This is my experience. Someone else might have other ideas.

+drive
08-20-2013, 11:46 PM
If you have a rear a/c then I recommend replacing that idler pulley. You can just remove the aux belt to see if that is your issue. If you don't have rear a/c then your aux belt is already removed and not the issue;)

JAM
08-21-2013, 12:28 AM
Def check the alternator pulley. I went through 3 bad remans in less than 4 months with mine. The 3rd one didnt have a clutch on it and it chewed my belt right up. These vans need the clutch on the alternators. I got the same screech as you too. The pulley on the alternator actually broke off. Never seen that happen before.

NelsonSprinter
08-21-2013, 12:47 AM
Definitely look at the alternator. The clutch or bearings may have seized .
My alt clutch seized and broke the tensioner off it's bolts, resulting in a long delay.
I wish I had replaced my alternator before 10 years were up, because I had to remove the front end and 3 rads to get the bolts drilled out and re-tapped.

neubath
08-26-2013, 04:08 PM
Replaced the alternator from a 90 amp to a 150, noise seems to have gone away. Also swapped out the belt tensioner. Amazingly got the alternator on Amazon, brand new Bosch for about $185.

seans
08-28-2013, 04:31 AM
Also swapped out the belt tensioner.

If you did not get the OEM tensioner, keep an eye on the tensioner as pfflyer mentions. There have been reports of aftermarket tensioners applying significantly more tension and also failing (see http://sprinter-source.com/forum/showthread.php?t=18310). Europarts began to source the OEM tensioner (Litens) earlier this year.

I wonder if loosening the serpentine belt and checking the belt condition, idler pulley smoothness, alternator pulley operation, and tensioner tension need to become inspection items during an oil change.