98 explorer making sound (like a blender)

[jonvil]

Need help please!! I have a 98 ford explorer sport. Sometimes the car makes sound like a blender if I release my foot on the gas. The sound goes away if I step back on the gas. It feels like the sound is coming in the front bottom part of the engine. Also the sound is like from a motor (could be starter? alternator? or something else). Anyone knows what could be it?

Thank you....

[shorod]

Welcome to the forum!

Can you duplicate the sound with the truck stopped and in park? You might try very slowly and steadily increasing the engine speed with it in park. I'm guessing somewhere around 2000 rpms you'll hear the noise, and it will turn out to be a loose heat shield on the exhaust, probably over/under the catalytic converter. If that turns out to be the case, you can probably find a very large hose clamp to put around the converter and heat shields to circumvent the broken welds.

-Rod

[jonvil]

Thanks Rod...

It does not sound anything loose. I had somebody check anything that could possibly loose under the car. The sound is like when you turn on a blender at home or like a little motor. It comes out occasionally. I will also try it when the car is in park tomorrow and will let you know if it would duplicate the sound. Thanks for your help.

Originally Posted by shorod

Welcome to the forum!

Can you duplicate the sound with the truck stopped and in park? You might try very slowly and steadily increasing the engine speed with it in park. I'm guessing somewhere around 2000 rpms you'll hear the noise, and it will turn out to be a loose heat shield on the exhaust, probably over/under the catalytic converter. If that turns out to be the case, you can probably find a very large hose clamp to put around the converter and heat shields to circumvent the broken welds.

-Rod

[wrightz28]

I'd put my first bet on the radiator fan acting up. That's if the catalytic converter heat shield checks out

Rod: funny you should say that, Home Depot used to sell the large 12-14" A/C ducting worm clamps but discontinued them. I used to keep a box of those laying around after my 3rd car an '88 Mercury Lynx (escort) had it's shield welding crack and learned this.

[jonvil]

Thanks wrightz28.

The catalytic converter heat shield was checked and no problem. The sound came out again one time while I was driving and the heat was on. I turned off the heat and the sound was still there. Do you think the radiator fan is good?

We also thought it was the cruise control motor and after replacing it, the sound still came out. The sound comes out once in a while. Thanks for your input.

Originally Posted by wrightz28

I'd put my first bet on the radiator fan acting up. That's if the catalytic converter heat shield checks out

Rod: funny you should say that, Home Depot used to sell the large 12-14" A/C ducting worm clamps but discontinued them. I used to keep a box of those laying around after my 3rd car an '88 Mercury Lynx (escort) had it's shield welding crack and learned this.

[Davescort97]

Check for the fan hitting on the shroud.

[shorod]

Try turning on the headlights and see if the noise seems to be more apparent. Maybe you're hearing rough bearings in one of the pulleys, such as the idler pulley, tensioner pulley, or alternator pulley.

Did you try to duplicate the sound with the truck in park or neutral yet?

-Rod

[wrightz28]

Originally Posted by jonvil

I turned off the heat and the sound was still there. Do you think the radiator fan is good?

So did you try and track it down while it was present?

[jonvil]

I tried it while the truck was in park/neutral and did not make the sound (blender or motor). The sound comes out every now and then specially when i get in to a certain speed (approximately 40mph) and when i released my foot on the gas, sometimes i will hear the sound and when i step on the gas or hit stop the car it will disappear.

Originally Posted by shorod

Try turning on the headlights and see if the noise seems to be more apparent. Maybe you're hearing rough bearings in one of the pulleys, such as the idler pulley, tensioner pulley, or alternator pulley.

Did you try to duplicate the sound with the truck in park or neutral yet?

-Rod

[shorod]

Oh, this may be similar to the noise I've been hearing in my 2000 AWD Mountaineer. After about 40 mph, the noise will come in while I'm cruising or coasting. If I step into the throttle, the noise will go away, but immediately fade back in when I let off the throttle. The sound is very consistent on my truck, any time I'm above 40 it will make it, regardless of temperature, time on the road, or weather.

I recently replaced the rear axle bearings due to leaking axle seals and that had no impact. I also changed the rear differential oil at the time and there were no shavings or signs of wear on the pinion or ring gears.

I've suspected it's pinion bearing, but my Dad (who has much more experience than me) says it sounds like a carrier bearing. Once I get around to replacing either of these, I'll post back and let you know the outcome. I haven't gotten to it for about a year now though, so it probably won't be any time soon.

-Rod

[wrightz28]

I'm sticking to my guns here, I really haven't looked into how the fan clutch is actuated on mine yet, but Blazers were notorious for sloppy fan clutches that make the sound you describe, be it the clutch or bearings.

Pay attention to your initial startup in the morning and listen to the fan when it runs clutched for about the first 5 seconds or so (mine does anyways), it should be lighter in tone due to less engine speed, but see if it is in fact remotely the same.

[vicv]

Just had this problem with my 97 Expy.. Let off the gas and hear the whirring noise. It started and then got worse over the course of a few months. The transfer case is worn and the gears are separating from each other. It is a known issue. I originally thought my tranny was bad but AFTER replacing it I still had the problem. I replaced the transfer case and problem is gone. Forunately for me the parts were from a junkyard and the whole job only cost $300.00. Search this and other forums for transfer case noise. Good Luck

[wrightz28]

oooh, that's a good point.

[tyefickes]

I have had 2 different sounds like that the first one sounded like a big gust of air, which was the clutches in the fan. You got to be careful about that get that done as soon as possible or it will make ur water pump go out, and the 2nd one sounds like one of those wheels you spin at a carnival with a arrow and its hitting on nails. if thats the sound then it one of the 2 timing chains mine was the 2ndary timing chain and gears. That one is expensive so hold ur breath the parts itself coast like 600 bucks then it 11 hrs of labor so it was over a 1K to get it fixed! hope this helps

[fordtrucksonly]

How many miles on the truck?