UPDATED w/video - v2001 Dodge Grand Caravan, 3.8 - strange grinding type noise
UPDATED - Added a video of the noise, see after the description
First the noise:
When I start the vehicle cold (i.e; in the morning) there is a god awful grinding type noise. I guess one could attribute it to a bad bearing. For about 2 minutes the noise is bad..but once the engine has warmed up..the noise greatly reduces..but is still present. I know it has to do with items connected to the belt because if I press the gas during the first 2 minutes...the noise speeds up..but also reduces quicker...I assume because I am warming the engine / parts up quicker.
I replaced most of the parts I thought were issues back last summer, so over a year ago. I replaced:
The alternator seemed like the most obvious cause and when you listen...seems like the noise is coming from it. However after we put a refurbuished one on there from Autozone...the noise was still there. So I think we are hearing a reverberating noise from elsewhere.
Last year, about 1-2 months before the noise I made the mistake of driving the vehicle when the power steering fluid drained out. We got it fixed and for a while the vehicle drove fine. Then the noises started. Well about 1 month ago I decided to have the steering rack and steering pump replaced as a mechanic seemed to think the pump may have been damaged or become bad because of losing the steering fluid and driving. Well, replacing those fixed some steering issues, but not the noise.
So I am wondering what else is connected to the belt. I know its a load issue as well, because if the car is placed into drive or reverse especially in those first 2 morning minutes, the noise is reduced but not eliminated.
Even after driving the car for 1 hour, if I put it into park and the AC is turned on, I can lightly hear the noise. If I turn OFF the AC, the noise *******ly goes away..but again this is with an already hot engine.
Not sure it matters, but before the noise started over a year ago, I had an transmission flush performed at Car-X. It was about 2-3 weeks after that the noise started. Not sure there is any relation.
I forgot to mention, I replaced the Serpentine Belt Tensioner last year as well, around the same time as the water pump, alternator, etc...
In fact, the belt tensioner was 2nd thing we replaced. That did not change the noise.
@master_tech - When we first started investigating the noise, I do believe we took the belt off to see if it was the cause, and it was. I will have to try again though.
Just an update. This morning I went to start my van to record the noise, and the noise was gone (amazing how that works).
When I say gone, I mean I could not hear ANY grinding like I have in the past. This is the 2nd separate time the noise has gone away. The first time, the noise was gone for roughly 2 months then came back with a vengeance.
I assume the same thing will happen again.
Any thoughts as to why the noise went away. If it was a bearing somewhere..I thought once bearings go bad they are bad. I wonder if there is a fluid issue somewhere.
Tizzy's comment is interesting, I will definitely look into it.