New Problem?

2000 3.8l

Ok, after all the previous problems with the coolant leak and then the brakes comes this strange problem.

It started about a week ago, and it usually only happens when the engine is cold but does happen from time to time at operating temp. The van runs perfectly fine until I hear the sound of the serpentine belt( or so i thought the belt) or more like a squeaking of a pully? (perhaps water pump?) as soon as i hear the squealing sound the van will start to stall! sometimes it wants to stall but jerks back and forth then keeps going. Now all is fine till i hear the squealing noise. anyone else hear of this?

The other day it was jerking back and forth sooo much at one point the cel came on and stayed on till i found the code and replaced the Camshaft Position Sensor...i think it was jerking so bad and squealing that it blew that sensor. Battery,alternator, belt, ect all checked out ok so im stuck as to what this can be.

I mention the water pump because the noise when it happens (sometimes idle in park will stall or start to) seems to come from the water pump area.

any ideas would help out greatly.

Something is locking up on your vehicle, even though the alternator checks good that could still be it. It might run fine for a bit then start locking up again. Water pump too. Take the belt off and try turning all of the pulleys, which ever one doesn't turn as easy is probably the problem.

I will try that because that is what i thought would be it...a lock up....man i hope it is not the water pump...but what could be the cause of a lockup..i mean as intermittent as it is? its just wierd.

Does this happen when the A/C or defroster is on? It could easily be the clutch on the compressor kicking in. I've had one go bad on another van that melted the belt. As someone else has mentioned, remove the belt and turn the various components by hand. Something is not spinning freely. Hopefully it's your alt (as it's easy to get to and replace!)

-P

"Synchronizer" perhaps? Do a search for more info.

As far as the serpentine belt.....make sure that it is tight.
The tensioner.....near the rear of the engine compartment....next to the firewall.....has both a pulley....that can go bad.....and a spring in the "arm" that holds tension in the belt....causing the belt to be tight on all the pulleys.

The A/C compressor kicks in in other settings than just the A/C.
It will be cycling in the defrost settings as well.
Mine even cycles in the heat only setting...
In my vehicle, the only settings that do not cycle the A/C compressor are OFF and VENT.
You might try to see if the problem happens when you have the system set in the VENT position.
I mention this because the A/C compressor places a big load on the belt....and is something that comes on and off.

You will also need to check the serpentine belt to make sure that it is in good condition.

The fact that you got a code for the camshaft position sensor leads me in that direction....but if you have strange things happening in the electrical system.....you can get false codes.
I would have replaced the camshaft position sensor.....easy to do.
The syncronizer is a bit more tricky to replace, so carefully follow the instructions.
Very important to MARK the position of the syncro before removing......and make sure to line up the new one identical to the old one. (providing that the old one was in the correct position to start with).

The pulleys can be hard to diagnose.......I had one that made a loud moaning sound......but only above a certain RPM while loaded with the belt......I could not detect any problem by spinning it by hand.
Also....the bolts that hold the pulleys in place can be quite difficult to turn.
I ended up with a breaker bar and a sledge hammer to get the bold for the idler pulley to come loose.

I have had bearings in the alternator get noisy, as well as a genuine Motorcraft alternator that melted its heatsink within a month of installation.
My water pump is still original on my '96 with 209K miles.