"I m sure if I go to the Dealer they will tell me to replace something again that I don't really need to replace. And charge me a fortune to boot!"
If the noise was still there, how could they charge you for fixing it? If the noise is gone, didn't they diagnose it and fix it, and deserve to get paid? The only thing I'd be cautious of is someone telling you it will take three, four, or more parts to fix it without a suitable explanation. That's a sign of throwing parts at it until they find the noisy one, then charging you for all the parts they tried. We used to have a shop like that here in town, and he gave everyone a bad name.
I assume this is something you've never heard before. Are you familiar with the ratcheting sound the transmission makes when you shift out of Park and when you slow to a stop? This is the time of year when people are starting to roll their windows down and they hear that clicking noise. Plus, if they just bought the vehicle over the winter, they may have never heard it before.
That ratcheting sound only lasts for one or two seconds. It is caused by the transmission's computer controls cycling the four shift solenoids. It does this when shifting out of Park, then watches for appropriate pressure sensor readings to verify proper operation. It does it again when stopping to cushion the downshifts rather than allowing it to bang into first gear. I realize this doesn't exactly match your description, but it shouldn't be forgotten.
The crankshaft bearing would be a loud knock and you'd probably have low oil pressure. Chrysler alternators, bearings included, give very little trouble. In the past, the bearings in the serpentine belt idler pulleys occasionally became noisy.
First, drip a little water onto the smooth side of the belt while the engine is running and you can hear the noise. If it clears up for a few seconds, then comes back, replace the belt. Before you remove it, look straight down from the section of belt near the engine mount down to the crankshaft pulley. Then compare the section of belt that goes over the spring-loaded tensioner pulley. If the tensioner appears to be moved away from the engine a little, it should be repalced to prevent belt squeal or damage. What you're doing is looking at the belt in three places and making sure they are all in a straight line.
Try running the engine after removing the belt. If the noise is gone, spin the various pulleys. If one seems tight or noisy, replace it. If they seem ok, try again while applying downward, then sideways pressure.
Chrysler had a lot of trouble with a loud buzzing noise coming from the water pumps on the 3.3L V-6 in the early 1990s but I would hope their supplier has solved that by now. A stethoscope works well for finding bearing noises.
Sunday, March 22nd, 2009 AT 5:37 AM