Engine howling (radiator fan?), thermostat housing questions

[mdisalvo]

My explorer engine started to howl at the end of last summer when the temperate was over 60 or so, mainly while under acceleration with the AC on, and it started back up now that it's getting warm again. I'm almost certain it's the radiator fan kicking into high gear as if the engine is overheating, but the temperate is always fine. I read that a lot of time this is somehow a result of a cracked thermostat housing, I've never seen any radiator fluid leaking, but is there any way to confirm this is the issue? Also are there any write ups on replacing it in an 04' 4.0 liter?

 

[JoshMcMadMac]

My explorer engine started to howl at the end of last summer when the temperate was over 60 or so, mainly while under acceleration with the AC on, and it started back up now that it's getting warm again. I'm almost certain it's the radiator fan kicking into high gear as if the engine is overheating, but the temperate is always fine. I read that a lot of time this is somehow a result of a cracked thermostat housing, I've never seen any radiator fluid leaking, but is there any way to confirm this is the issue? Also are there any write ups on replacing it in an 04' 4.0 liter?

It could be the viscous coupling on the fan.

 

[mall]

This is just a hunch and I am no expert, but check your Idle air control (IAC)

 

[mdisalvo]

I don't think my car has the IAC, from what little I understand it uses the MAF sensor instead which I cleaned a few months ago. This is more of a roaring/jet engine noise than a whistle or whine. I bought a new clutch fan from advanced auto parts and will be replacing that in the next couple days to see if it fixes the issue.

 

[pet575]

mall, did you mean a fan clutch?

mdisalvo, do you mind reporting back after you change that fan clutch? I've had the roaring for quite some time (especially when the engine is cold) but I've never done anything about it.

 

[mdisalvo]

Pet-my roar seems to happen more under acceleration (it really gets going on the highway sometimes) when the weather is warm, so I won't know if it's fixed for sure until the temperature gets above 60 again. I replaced the fan clutch and so far it seems to be running well, it seems to engage a little more at start up, but other than that I can't tell any differences. I bought this one at advanced auto parts for 54.00 total after using a 20% off coupon code online.
http://shop.advanceautoparts.com/we...uty-imperial_15230033-p?searchTerm=fan+clutch

Here are some pictures I took, it was really quite easy, it took me about an hour:

1. Removing the fan shroud-removed 2 bolts and it slid right out (you can see the holes for where the bolts were on the left and right side of the shroud)

2. What it looks like with the shroud removed

3. The tools I used, the big wrench on the right came with the rented tool set I got from advanced auto parts, it's used to keep the water pump pulley from spinning when you loosen the nut holding the clutch on. Note-the kit came with some wrenches designed to remove the bolt too, but none of them fit the bolt on my car so I used a large crescent wrench instead.

4. Getting the wrenches in place. Once you get the wrenches situated, hold the large wrench that is holding the water pump from spinning in place and turn the wrench on the bolt counter clockwise (towards the passenger side) and the nut should come loose. Mine was pretty easy to get loose, then I just held the wrench on the water pump pulley and spun the fan blade to fully remove it.

5. The fan removed with the clutch still attached. I put my fan in the sink and gave it a quick rinse as it had some dirt caked on it. Remove the 4 bolts and then the clutch should pop off and now you can replace it with the new clutch.

6. Put the fan back in the car and do the opposite to re install it.

 

[mall]

mall, did you mean a fan clutch?

mdisalvo, do you mind reporting back after you change that fan clutch? I've had the roaring for quite some time (especially when the engine is cold) but I've never done anything about it.

No, I meant IAC. I thought his description sounded similar to the sound that my F250 is making...but if there is no IAC then I must be wrong.

 

[mall]

I don't think my car has the IAC, from what little I understand it uses the MAF sensor instead which I cleaned a few months ago. This is more of a roaring/jet engine noise than a whistle or whine. I bought a new clutch fan from advanced auto parts and will be replacing that in the next couple days to see if it fixes the issue.

I looked up on Auto Zone to see if my 03 Explorer had an IAC and mine does have one. I don't think a fan clutch would be affected by air temperature, water temperature and the fan speed can only change when you step on the gas. The fan does not run faster when the engine is hot...it is completely dependent on the engines RPM.

I could be wrong, but I think it sounds like the IAC.

 

[mdisalvo]

Someone feel free to correct me if I'm wrong but I believe 2004 was the year they stopped using the IAC. My symptoms were more like the clutch was getting stuck in place which is why I decided to replace it.

 

[pet575]

My bad, Mall. It was the post before yours (from Josh) that I was talking about. Meant to put his name down when I wrote yours in talking about the fan clutch.

I believe that the 2004 info is correct; no IAC as far as I know in the 2004's.

 

[mall]

Someone feel free to correct me if I'm wrong but I believe 2004 was the year they stopped using the IAC. My symptoms were more like the clutch was getting stuck in place which is why I decided to replace it.

From the Auto Zone web sight.

Duralast/Idle Air Control Valve
For your 2004 Ford Truck Explorer 4WD 4.0L SFI 6cyl
Price: $39.99

If you have the V8 it has idle air control motor. I am not sure if that can cause the same sound. I am not saying that I am correct, just that it sounds odd that a fan clutch would only make noise when it is hot outside.

 

[JoshMcMadMac]

My bad, Mall. It was the post before yours (from Josh) that I was talking about. Meant to put his name down when I wrote yours in talking about the fan clutch.

Yes, I was referring to the fan clutch. I suppose viscous coupling is just a "fancy" way of denoting it.

I don't think a fan clutch would be affected by air temperature, water temperature and the fan speed can only change when you step on the gas. The fan does not run faster when the engine is hot...it is completely dependent on the engines RPM.

The fan does run faster when hot, thus the purpose of having a clutch. If you spin a new fan clutch sitting at room temperature, it will spin much easier than if it were heated...engaging the clutch. That is the easy way of checking to see if one needs replaced; drop the serpentine belt and if the fan does not spin freely when cold, the clutch is worn.
http://en.wikipedia.org/wiki/Fan_clutch

 

[mall]

Yes, I was referring to the fan clutch. I suppose viscous coupling is just a "fancy" way of denoting it.


The fan does run faster when hot, thus the purpose of having a clutch. If you spin a new fan clutch sitting at room temperature, it will spin much easier than if it were heated...engaging the clutch. That is the easy way of checking to see if one needs replaced; drop the serpentine belt and if the fan does not spin freely when cold, the clutch is worn.
http://en.wikipedia.org/wiki/Fan_clutch

Thanks, I guess I can't be right about everything.

 

[mdisalvo]

Just an update on this, it did fix the issue of the howling radiator fan at certain temperatures. It was happening when the engine was heated up and the weather was above 65-70 out, ever since replacing the fan clutch it's been working great. Initially the clutch stays engaged when starting up the engine, but from there on out it is only engaged when necessary, unlike before. Hope this helps.

 

[jghake]

I have this same howling issue in my '03. It started making the noise on the trip home from purchasing the truck...

I sprayed down the engine compartment with a power sprayer at the DIY car wash and it quieted down a bit but every once in a while it gets loud again. I can't say it does it when its warm out (I live in WA State and its never warm...) but it only does it sometimes and now that I think about it doesn't really ever happen when its cold/rainy. I will keep an eye on it and if I hear it acting up more I will replace this clutch.

Thanks a lot!

 

[JoshMcMadMac]

I have this same howling issue in my '03. It started making the noise on the trip home from purchasing the truck...

I sprayed down the engine compartment with a power sprayer at the DIY car wash and it quieted down a bit but every once in a while it gets loud again. I can't say it does it when its warm out (I live in WA State and its never warm...) but it only does it sometimes and now that I think about it doesn't really ever happen when its cold/rainy. I will keep an eye on it and if I hear it acting up more I will replace this clutch.

Thanks a lot!

If it is on the original ten year old fan clutch, replace it anyway. They wear out, and it will pay for itself eventually in improved fuel economy.

 

[mdisalvo]

I agree, it was cheap and easy and my cars running better now, not much reason not to.

 

[Mac McElroy]

i know it sounds crazy but check your idler pulleys mine did this and it was my bottom idler pulley

 

[Apachek]

Pet-my roar seems to happen more under acceleration (it really gets going on the highway sometimes) when the weather is warm, so I won't know if it's fixed for sure until the temperature gets above 60 again. I replaced the fan clutch and so far it seems to be running well, it seems to engage a little more at start up, but other than that I can't tell any differences. I bought this one at advanced auto parts for 54.00 total after using a 20% off coupon code online.
http://shop.advanceautoparts.com/we...uty-imperial_15230033-p?searchTerm=fan+clutch

Here are some pictures I took, it was really quite easy, it took me about an hour:

1. Removing the fan shroud-removed 2 bolts and it slid right out (you can see the holes for where the bolts were on the left and right side of the shroud)

2. What it looks like with the shroud removed

3. The tools I used, the big wrench on the right came with the rented tool set I got from advanced auto parts, it's used to keep the water pump pulley from spinning when you loosen the nut holding the clutch on. Note-the kit came with some wrenches designed to remove the bolt too, but none of them fit the bolt on my car so I used a large crescent wrench instead.

4. Getting the wrenches in place. Once you get the wrenches situated, hold the large wrench that is holding the water pump from spinning in place and turn the wrench on the bolt counter clockwise (towards the passenger side) and the nut should come loose. Mine was pretty easy to get loose, then I just held the wrench on the water pump pulley and spun the fan blade to fully remove it.

5. The fan removed with the clutch still attached. I put my fan in the sink and gave it a quick rinse as it had some dirt caked on it. Remove the 4 bolts and then the clutch should pop off and now you can replace it with the new clutch.

6. Put the fan back in the car and do the opposite to re install it.

 

[Apachek]

Thanks for DIY guide as I replaced mine as well, 2003 Ford Explorer 4.6L V8 engine. I bought a new viscous fan similar of what you've got from Rockauto.com.

https://www.rockauto.com/catalog/x,....com.au+Search+for+2003+FORD+EXPLORER+4.6L+V8

Pretty good it solved the howling noise and improved fuel efficiency.

For those who have similar issues, 3rd generation explorers you can buy viscous coupling on line. The wrenches or proper tools are necessary which will cost you about $50 bucks. To hold the pulley 4 bolts, I just made up one using a flat bar 2mm x 2" x 16" long and bore 2 holes to hold just 2 of the 4 bolts from rotating the pulley spindle.

http://www.ebay.com.au/itm/301150994414?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

TIPS:
1. Counter clockwise direction to loosen.
2. Clockwise direction to tighten.
3. Takes probably an hour or 1.5 hour to do the job.
4. Great savings if you DIY, $$$$$$$$.

Thanks for the thread, you're a champ.