Cooling fan

[Darol Wester]

Here's a test I found I'll try. It might isolate your problem too. Run the truck until it warms up and then feel each of the two heater hoses to see if they're both warm or one is and the other is not. If that's the case, the heater core or a hose could have blockage it. If so, run a water hose in both ports of the core (not too strong) and see if it might blow something out. Same with the heater hoses. The fan sounds like a goofy switch.

 

[Kyure]

Darol, I'm getting so frustrated. But too stubborn to do anything under the hood but cut the dam wire turning that fan blowing on the radiator. I dread a trip to the store to buy food or go get coffee with my daughter. Same things happening with my computer. Can I throw it all away and start over?

 

[Darol Wester]

My apologies K. I've been eating lots of cold medicines/drugs this last week and mistakenly thought High was the one with the problem. I would think that the fan wire would have a disconnect somewhere inline. It definitely should be fused. You should have a book or a schematic somewhere showing the fuses. Did you try banging on it with a big stick? I've gotten results occasionally with that method, but not very often.

Like some have said here, a sensor or relay can also be the culprit. I'll check with a mechanic bud of mine and see what he says about it.

This is a 350 Chevy in what vehicle and year? Great motor by the way.

 

[Floorist]

I think he said it was a 2001 Express.

 

[Darol Wester]

Yep, thanks. I missed that.

 

[Darol Wester]

Out of curiosity, does anything change when you turn your A/C off and on when the fan is running?

 

[Darol Wester]

An interesting read. Understanding the fan.

http://independent.co.ug/society/motoring-/5254-is-your-vehicle-cooling-fan-running-all-time

 

[highup]

01 express. It's the radiator fan. The temp gauge in dash barely moves. The heater blows but its cold, not ice cold but cold. I'll check on the hose.

I've been confused about the radiator's fan being electric. I don't work on "newer" vehicles like yours ,however I still thought it would be very strange for a van to have an electric fan, unless it was a additional fan added for towing and heavy duty use.
I found this link and it shows these engines come with a standard issue clutch fan which is driven by the pulley on the water pump. They can go bad. My clutch fan went bad and the clutch didn't always disengage......... is sounded like a jet engine under the hood, especially at low speeds.
Vans are sometimes difficult to look into because of the hood and fan shroud. Does yours look like this?
http://troubleshootmyvehicle.com/gm/4.8L-5.3L-6.0L/bad-fan-clutch-troubleshooting-case-study-1

 

[Darol Wester]

Does the fan come on when you turn the key on, or just when the motor is running?

 

[Kyure]

Out of curiosity, does anything change when you turn your A/C off and on when the fan is running?

A/C is a whole nother issue I started having the past summer, it comes and goes intermittent as it pleases.

 

[Kyure]

Does the fan come on when you turn the key on, or just when the motor is running?

No it starts spinning as soon as I start it

 

[Kyure]

Highup - I'm pretty ignorant when it comes to vehicles and computers. It's not attached to the belt so I assumed electric.
Edit - Yes! It sounds like a jet engine, good call.

 

[Darol Wester]

OK....After thinking about this some more, I think your first thought of replacing the sensor COULD be in the right direction. As cold as it is where you are, and the fan running full speed, it would be tough go for the motor to warm up very much. If you disconnected the fan and then run the motor, I'll bet it warms up like it use to. A new sensor looks to be around $12. I'd go for that and see what happens. It is throwing parts at it, but a cheap part.

Also, did you get the thermostat in correctly? Spring side in the engine?

 

[Kyure]

Thanks for reply Darol. I was thinking sensor too and it's pretty cheap. My big shmeal right now is it's cold out, though we're getting 50's this weekend. And I dreaded going under the hood, tho gettin in it to go store was dreadful as well with no heat. I'd have to remove a bunch of crap to even get to where the thermostat is. But hopefully we pull some gulf air and sun soon.

 

[highup]

Highup - I'm pretty ignorant when it comes to vehicles and computers. It's not attached to the belt so I assumed electric.
Edit - Yes! It sounds like a jet engine, good call.

Every place I look, it shows a mechanical fan on these vans, and they are driven by the water pump pulley. Attached to the water pump is a thermally controlled fan clutch to which the fan is connected. If that clutch part goes bad, the fan can be spinning all the time, even when it's not needed. That might cause the jet engine sound.
When the engine does not need cooling, such as when the engine is cold, or when you are driving above 20 or 30 miles per hour the fan clutch lets the fan blade freewheel. When the engine is hot an needs cooling, the clutch engages and makes the fan spin.

http://www.stylintrucks.com/parts/h...ent_fan_clutch/HAYFA55141/haydenhy2626-.aspx#


I don't think the fan or fan/clutch issue can cause the heater to be cold.
If the clutch is defective, the engine's cooling fan could spin continuously, even when the engine does not need cooling.

 

[highup]

Have you ever changed the coolant in the radiator?
What color is the coolant? Green or Orange?

 

[Darol Wester]

Me thinks that K needs to take a really good look at the fan assembly one more time. I've looked on Rock Auto for cooling system parts and they only list clutch fan parts for his van, regardless of the motor in it. Also, this comment from a Chevy forum I visited this morning.


"Re: Radiator fan 2001 Express 5.7

If the fan is running with the engine off and key out of the ignition then its a electric fan.
If the engine is running and the fan is making a roaring sound when using throttle, (As you mentioned) like an airplane then its a clutch fan."

I think you're right High. We'll see what K finds in one more look at it. Sure would be nice to have a peek under the hood.

Take a picture of it K and post it.

 

[Kyure]

You guys are right, told ya I'm not to keen. Going to replace the sensor today.

 

[Darol Wester]

Before you do that, make absolutely sure that this fan isn't driven by a belt K. The Chevy people say that that rig came stock with a clutch fan. A sensor won't help that.

 

[Kyure]

Ok thanks, I'll look closer, we're getting to 60 today so I won't dilly dally. I'll get a better look before deciding it's electric this time!

Edit- yep its connected to a pulley running on a belt