Oh no, please tell me it isn't the crankshaft.

[KYEdge]

2002 Ranger, automatic transmission, 107K on the clock. It hasn’t exactly been a mechanical upgrade over my old 94 Dakota.

There is a screeching sound coming from somewhere around the front of the engine. I can’t place it exactly, but it sounds to be coming from somewhere around the middle of the engine and behind the belts. In other words, I’m about 60% certain it sounds like it is coming from around the crankshaft pulley. It is intermittent, and seems to come and go as I’m driving, but is the loudest when the RPMs drop to near or at idle.

I’m not really sure how to describe the sound either; it isn’t anything like a belt squeal, it is almost like nails on a chalkboard. My initial “oh crap” reaction was a bad crank bearing, but other than stalling out once while sitting at a stop light, the engine seems to be running fine.

Please, please tell me there is some part down there around the crankshaft that I don’t know about, and it is cheap and easy to replace.

 

[Earl43P]

Remove the serp belt.

Could be the water pump. If its pulley wobbles, pull the pulley off and check the weephole for evidence of leaking. No wobble, no worries.

Spin the idler and tensioner pulleys.
You can tell a bad one. They run ~$18 ea.

Start it with the belt removed to confirm its one of these. Run it long enough to be sure, less that 20-30 seconds should be plenty. You can do that a few times if you wait a while between runs. No coolant flow with the belt off.

There is no reason to suspect a crank problem until you rule these out.
All you need to remove the serp belt is a 15mm wrench and maybe another wrench as a cheater extension. Use the tensioner pulley bolt to remove the tension (tightening direction), then slip the belt off the alternator pulley.

If you've had this truck since new or thereabouts and have never replaced either of those pulleys, I'd just do both pulleys and put a Goodyear Gatorback belt on (they are pretty expensive).

 

[KYEdge]

Well, I tend to jump to the worst conclusions... it makes me feel better when it isn't so bad! lol

I guess this weekend I'm gonna have to get my dad to help try and pin point the location of the sound and then start testing things.

I was really really worried though that it was going to turn out that that crankshaft bearing was the only possibility.

 

[Viper Command]

Well mine sounded like a ratteling knock, much like a spun bearing or thrown rod but ran smooth no mis or shake.....

It was my oil pump going out. long story short, I couldent pull over and kill it before cyl. 1&4 rods welded to the crank..


better safe than sorry.

 

[fourwheelford]

It wouldn't be the Cam positioning sensor. Its most likely the cam shaft syncro they squeal before they die, I would bet money thats your problem at that mileage. The sensor sits on top of the shaft, people alway ALWAYS refer to these as the same thing but they are very different, one causes complete engine failure(syncro) and one just throws a code(sensor) 140 bucks for an oem one and a few hours of time should kill your squeal.

 

[KYEdge]

It actually did turn out to be the cam syncro. We looked all over and no one, between four people listening, could agree on where the noise was coming from; so I eventually took it to my local shop. They knew what it was pretty much from the get go.