roaring fan, 4.6, issue ongoing

[ThunderbirdSport]

Hey y'all, it's me again with my hypochondriac-assed Explorer LOL.

Anywho, when the engine is up to temp (or in the middle of the temp gauge) the fan will make a roaring sound.

I did search for this, did find one thread but it was kinda vague as to the fix.

I don't think the fan clutch is bad, as when the engine hasn't been ran in awhile it's resistant to turning by hand.

I've read there's a switched clutch, indeed, there's come wiring and an electronic device like I've never seen on an engine before...I wondered about it the other day while I was wrestling a shroud into place...

Any tips or methods to check it out in more depth?

My code reader only gives me a code for out of range O2 sensor(s)...not sure if a bad fan clutch or controller or whatever it is would throw a code in the first place...hell, for that matter, my podunk code reader might not even be able to access it..

As always, thanks in advance!

 

[michael loibl]

The roaring sound is when the fan clutch engages to maximize air flow. Normal under some conditions such as running the A/C at low speeds, hot weather, towing, and driving up steep hills.

However, if it is roaring away in mild driving, there is a good chance you are low on coolant. These gauges are designed to stay in the middle range even as temperatures climb to around 230, then they abruptly climb toward HOT.

 

[ThunderbirdSport]

Coolant's topped off, though it likely wouldn't hurt to have it flushed. I'll do that Saturday..

 

[gmanpaint]

The fan clutch will free spin very easily, until activated. If it doesn't free spin, after the engine is cooled off, time for a new one.

They are mechanical, so not sure what you mean by Electronic device. Share a picture, so we can see what your talking about.

 

[Explorer_PL]

I know nobody wants to just throw parts at a problem, but mine did it somewhere between 150-200k.

I replaced the clutch/harness with OEM Motorcraft part and it's been good for the past + 100k.

 

[DavidEBSmith]

In 230K miles we've replaced it twice. Brand new it almost always roars for a few seconds at startup, even when ice cold. Then at some point it starts roaring inappropriately and my wife gets annoyed and we replace it.

 

[michael loibl]

It’s mechanically driven, but electronically controlled. There is a wiring harness running to the fan clutch that can make it lock up when computer determines it should, such as when A/C is on

 

[ThunderbirdSport]

The fan clutch will free spin very easily, until activated. If it doesn't free spin, after the engine is cooled off, time for a new one.

They are mechanical, so not sure what you mean by Electronic device. Share a picture, so we can see what your talking about.

pic below, circled in red is what I'm referring to. This is the fan harness, no? It appears to run down into the fan's clutch area...somewhere...first time I've ever seen anything like this on any of my vehicles..lol

 

[07EddyB]

Yeah - michael covered that in the post above yours. gmanpaint may be thinking about the earlier gen.

 

[gmanpaint]

Yep, my bad. Whoops.

I looked up your rigs fan set up on rock auto, and seen the switch.

 

[07EddyB]

Yep, my bad. Whoops.

I looked up your rigs fan set up on rock auto, and seen the switch.

If you have ever wondered how some people get to be Moderators then you just got a lesson.

 

[gmanpaint]

If you have ever wondered how some people get to be Moderators then you just got a lesson.

Meaning??

 

[07EddyB]

Meaning??

You followed up and acknowledged your mistake. That's getting rare on the net.

 

[ThunderbirdSport]

Today I went into town for some lawnmower gas and ice cream for the kids, out on the highway (70mph) with the AC on, the gauge went up, the info cluster turned red, and the ice cold AC got a little less so.

However, if left to idle with the AC turned off, the temp will very quickly go back to normal, or the middle of the gauge. I'd suspect the water pump is ok....think it's some trapped air in the cooling system?

When I got this thing, the coolant was low...I topped it off and didn't have any problems aside from the lack of a fan shroud (that I resolved, made a thread ICYMI).

I'm open to suggestions....not sure how I'd get air bled out..?

 

[07EddyB]

Either Jack up the front or park it facing up hill. Run it with the front and rear heat on and be ready to add more coolant.

 

[gmanpaint]

Blower on high too.

Don't build pressure when bleeding it. Open the rad cap halfway. Run for 10 mins or so after it's up to temp.

Friend roasted his 04 engine in his Ex, from not bleeding the coolant system, after a flush/fill. Don't wait to do this.

 

[ThunderbirdSport]

roger roger. Thanks guys...will do this ASAP.

 

[ThunderbirdSport]

So I bled it the other day, and when the AC is off, the temp stays in the middle, with the air on, in about ten minutes, the gauge shows hot, the needle is at the top and the cold air no longer blows cold.

It also does it with the air on and idle...vehicle speed doesn't matter.

I would think the coolant is fine if it doesn't overheat with air off, no?

I will bleed it some more saturday, and I wonder if I hadn't ought to put a fan clutch on too?

 

[gmanpaint]

Might have some air trapped still. Make sure the front is much higher to let the air out. Cap halfway on.

While doing this, look inside the rad, and see if the coolant is moving at all. Then check to see if the air inside, is blowing hot.

When done, and you close the cap all the way, run it again, and watch the hoses. If they seem to collapse at all, that's a problem. If they are both hard to squeeze, then your good. If one is soft, and the other hard, that's a problem.

Might need a new t stat. Might need a pump. Might need a heater core. Might need a core valve. Might just be air.

If you can get a good digital scanner, you can read the actual water temp as you do your tests, and afterwards to compare.

 

[ThunderbirdSport]

Yeah, it blows hot as hell, there's movement in the coolant, such as when I have the wife give it a little gas while I watch it.

I'm gonna get a t-stat tomorrow....seems like a 16# cap is the order of the day?

It's running right now, about to go put the cap on watch the hoses. I think it's air, and I've got some of it out, it still wants to get hot but not as fast as before. It's getting warm...my old ass like the cold air on the way to work LOL.