Noise like a single engine airplane!

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1

I have an '89 Ford Ranger 2.3L std transmission with 220K mis. A couple weeks ago I noticed what sounds like a pretty, loud low hum at speeds >45mph. Otherwise it runs great with no apparent transmission problems. Should I be worried?

2

At that age anything is possible. the first places to look IMHO are at the tires (for wear), at the exhaust (for holes and loose hangers or parts like a heat shield), and at the driveshaft (for a bad U-joint).

3

Can rule out tires, just put two new ones on and the remaining two checked out okay. U-joint is possible. I’ve pertually had problems with them on this truck even after replacing the drive shaft. Must be a “factory setting” we’re unaware of ;-). Thanks.

4

What cab? Does the driveshaft have a carrier bearing?

5

The radiator fan speed is thermostatically controlled via a fan clutch.

With the engine cold, try spinning the radiator fan by hand. It should spin a few times. If not, the fan clutch is locked up and requires replacement.

Tester

6

I’d put odds on a wheel bearing. Especially so if the noise changes at all when you turn. (e.g. reduces or disappears while turning one way or the other).

7

That was my first thought but there is no noise at low speed or on turning.

8

Fan turns freely.

9

Extended cab…and I don’t know.

10

If it’s an extended cab it’ll probably have a carrier bearing. That’s still a possibility in my mind.

11

The low speed noise wouldn’t shake my bets - but if it doesn’t change at all when turning…well, that’s a different story. The one possibility there is that they are noisy on both sides. Its worth jacking it up & giving the wheels a spin.

Of course I’m also not saying to rule out other things - like the carrier bearing (mtnbike above & below)

12

Thanks everyone! It turned out to be the bearings.

13

Hold up a minute,we deserve to know what bearings and what test led them to this conclusion. Was it just one side and you were pursuaded with the old “if one is bad the rest are sure to follow” Even though you don’t answer many questions your info is still valuable to readers of CarTalk,contribute, it will be appreciated.