Fan clutch engaged on cold startup on 4.6 V8?

[DavidEBSmith]

Lately, occasionally, on cold startup, my wife has noticed that the fan clutch on our Mountaineer engages with the accompanying roaring sound. It stays engaged for anywhere from 10 to 30 seconds, then disengages. It hasn't been hot enough around here that it engages any other time. The fan clutch has been replaced at least once, under warranty, so the current one has about 50-60K miles on it.

Since the noise really bothers my wife, I would just replace it, but for the cost, and that I found this: Rock Auto has fan clutches from Four Seasons, Hayden, and Motorcraft. On the Hayden page it says:

Electronic-Viscous Fan Clutch Troubleshooting During engine start up, the EV fan clutch will engage and match engine speed for up to 3 minutes. This is considered normal and may last more than 3 minutes in cooler climates or at lower driving speeds resulting in fan roar.

- Do NOT replace EV fan clutch unless a specific issue is identified by proper SI (Service Indicator / Check Engine) diagnosis.
- Do NOT replace an EV fan clutch for fan noise.

In searching old threads on the fan clutch, it looks like it pretty much never throws a code on our vehicles. And I looked in the Ford service manual and didn't see anything about the fan clutch engaging at startup.

So is it correct that the fan clutch on Explorers/Mountaineers will normally engage at startup - even cold startup? Or is sticking at startup a sign that the fan clutch is on its way out?

 

[Flag Gibby]

I don't consider it to be a sign of the fan acting up. I can occasionally have mine do that when I start the vehicle with the HVAC system in auto mode and the system immediately kicks the AC on. The fact that it shuts off so quickly says to me that there is nothing wrong.

 

[MotorCityFats13]

on my 4.0 it sounds like it engages on every start up almost like part of a systems check and after 10-20 seconds clicks off and the fan moves less air... so far the only time I can tell its engaged is when I first start it up.... I bought it back in december so I still have not driven it on a really hot day

 

[07XLT4x2v8]

My fan clutch seems to be coming on more and more often, even in normal weather (70-75). Lately it has been getting hot (today 92 deg) and the Explorer will start to overheat if idling for a long time at a light and the A/C is on. I'm going to take it in and have the fan clutch tested.

 

[Flag Gibby]

It may have nothing to do with the fan clutch. You could have a coolant leak that is causing the system to overheat.

 

[07XLT4x2v8]

I sent you a pm as I don't want to highjack this thread.

 

[RJ]

It may have nothing to do with the fan clutch. You could have a coolant leak that is causing the system to overheat.

But upon startup? Even with no coolant the metal block would take a minute or two to warm up.

I wonder if it's the re-programmed ECU to help prevent leaking rads. That's one of Ford's TSBs to help combat the failing radiators, suppose to increase fan running cycle.

Obviously it isn't working so well, my fans also roars on startup and I'm on my 3rd rad...

 

[Ronin8002]

Mine does it. Cycles off after a minute or so once the engine starts to warm up.

Only had one radiator leakage issue.....I replaced the radiator, flushed the system, and installed a lower pressure radiator cap 2 years ago. So far so good.

 

[Mart1n]

Lately, occasionally, on cold startup, my wife has noticed that the fan clutch on our Mountaineer engages with the accompanying roaring sound. It stays engaged for anywhere from 10 to 30 seconds, then disengages. It hasn't been hot enough around here that it engages any other time. The fan clutch has been replaced at least once, under warranty, so the current one has about 50-60K miles on it.

Since the noise really bothers my wife, I would just replace it, but for the cost, and that I found this: Rock Auto has fan clutches from Four Seasons, Hayden, and Motorcraft. On the Hayden page it says:



In searching old threads on the fan clutch, it looks like it pretty much never throws a code on our vehicles. And I looked in the Ford service manual and didn't see anything about the fan clutch engaging at startup.

So is it correct that the fan clutch on Explorers/Mountaineers will normally engage at startup - even cold startup? Or is sticking at startup a sign that the fan clutch is on its way out?

Hi, I know it's an old thread of yours, but I'm experiencing similar unnecessary engine fan running. Did you ever find / fix the cause of your problem? Thanks