Hello all, noob here on the forum with a question. I have a 97 Mazda B4000 4WD with 94k on the clock that's making a chirp/squeal from the underhood area. I thought it was a bearing going in the water pump, so I just replaced it tonight. Noise still there. I ran it with the fan off, noise still there, so I pulled the belt off and it still has this squeal. At this point I'm wondering if it's the front oil seal but I don't see how a rubber seal can squeal. The noise sounds a lot like a slipping belt, even though it does it with the belt off. Another thought that crossed my mind is (gulp) front main bearing failing. Any suggestions? I had the presence of coolant in an oil sample a while back according to the Blackstone report, but the second sample I sent in had negligible coolant in it. I traced that to the timing cover gasket seeping and tightened the bolts down. Thanks!

 

Try using a long screwdriver as a stethoscope and see if you can hear where the noise is loudest. BE CAREFUL around all of the moving parts.

hj

 

I used my stethoscope on the water pump, putting the point of it on the WP housing and the noise was louder towards the impeller of the pump. I didn't try it with the belt off though so I blew 50 bucks on a water pump that I didn't need. I'm going to get somebody to come over and sit in the truck with their foot on the brake before I climb under it with it running. I'll give it a poke with the scope around the crank pulley and tranny then let ya'll know what I find. I do know the noise doesn't change when I mash the clutch in and it speeds up with engine revs.

 

Is there any chance you have the 3.0L v6? If so, it could be the camshaft sensor/synchronizer shaft assembly.

https://www.ford-trucks.com/forums/2...placement.html

 

No, I'm sure it's the 4.0, VIN X but it could still be the cam sensor on the back of the block. I called a friend of mine that's a Ford tech and that was the first thing he thought of. It's a bugger to get to but if that's what it is, I'll break out the tools and try to fix it. I saw that mentioned on another thread, especially the part about losing the oil pump if the cam sensor fails. I gave it a brief listen when I was home on lunch and heard a little chirp come out of it but didn't have time to let it sit there and idle long enough to really know. I've got a meeting tonight so I'll try again later and see what it does. I guess I can find the intake r&r process somewhere on here along with the torque specs and part numbers. One thing I have noticed in the last couple of days is the idle is a little rough. It was loping a bit yesterday, enough to rock the truck around some, almost like it had a high lift cam in it.

 

I checked it out this evening with the scope and I feel sure it's the cam sensor/syncro shaft. With the tip of the scope on the wiring plug, it screeched a couple of times in my ear, loud enough to hurt my ears. High pitch, like fingernails across a chalk board. What is it I'm hearing? Dry bushings? Is this common on the 3.0/4.0 V6? I got the cam sensor out for a visual inspection and it appears fine. Any ideas?

 

Well, I finally got around to replacing that cam syncro assembly and that took care of it. I turned the gear by hand and it squeaked in my hand with a lot of drag on the shaft. I guess the bushing was dry or gooked up causing the shaft to stick. Any ideas of why this part went bad or anything I can do to keep it from happening again? I've only got 93k on this truck so I hope this doesn't happen again. You folks helped steer me in the right direction! Thanks!