Question 7.3 loaded or unloaded

[GB1982]

I have a 2002 with 7.3... I have seen where some people talk about fan kicking on.. My truck when you stop the fan will kick on when you start off and usually go off when I reach overdrive. Every time it will do this in the summer. Also riding down the interstate no load at 70 mph . My truck fan will kick on and stay on for what seems prob 3 or 5 minutes maybe. I am just wondering if clutch it going bad, or if I should look somewhere else. Also A/C will not blow hard and it seems to start blowing warm. System is charged. So anyone That can Help I would appreciate.

 

[BJS]

Welcome to the site.

Driving down the highway it is very unusual for the fan clutch to kick in on these trucks.

There are a host of potential problems but two are the most likely culprits

1. bad fan clutch - when the truck is off and cold try to turn the fan by hand there should be a slight resistance (a bit more than there is turning a door knob) but you should be able to easily turn it

2. debris in the intercooler, A/C condenser, & radiator stack. I tore the radiator out of my uncles RV to solve this exact problem (we thought it was clogged tubes since it would over heat easily too) I discovered that the front side of the radiator was covered in a thatch like mess effectively blocking the air flow to the center of the radiator, I was amazed at how little was actually clear and the 454 was staying cool unless the a/c was on.

 

[silverF250]

My brother had the same ac problem I'll ask him today to see how he fixed it. I know it was simple and didn't cost money.

 

[GB1982]

i hope so

I have actually cleaned at that out. I know what you are saying though. If there is thatch or nest like material, well there is only one way to get that out. I am only racking my brain because it does it unloaded and should not be at all. I have pulled some big trailers like a 40' enclosed. As far as pulling it is not hurt, ...yet.

 

[JLDickmon]

loaded or unloaded, doesn't matter.

What does matter is the amount of airflow getting through the stack of condensor, intercooler and radiator.

I gotta go with Brandon on this one.. I think I'd be looking for mice in the stack...

HOWEVER... I think I'd also be wondering if you're feeling the EBPV (Exhaust Backpressure Valve) trying to keep the engine warm. Ain't it like, the coldest it's been down there in like 40 years?

 

[GB1982]

loaded or unloaded, doesn't matter.

What does matter is the amount of airflow getting through the stack of condensor, intercooler and radiator.

I gotta go with Brandon on this one.. I think I'd be looking for mice in the stack...

HOWEVER... I think I'd also be wondering if you're feeling the EBPV (Exhaust Backpressure Valve) trying to keep the engine warm. Ain't it like, the coldest it's been down there in like 40 years?

Well no i know what your talking about. The fan kicks on I mean on this truck hell yeah you know when the fan is on lol. I guess I need to take the top cover off and have a look see on whats going on. When I said loaded or unloaded I was just saying that I could understand if I had a big load on it. I would expect it to do it then maybe. But no since its been cold it does not do it.

 

[BJS]

Yank your fan off and drive it around without the fan. JL brought up a rather good point that it might be the the EBPV that you're hearing as it has a similar sound to a fully engaged fan clutch. You can drive around without the fan in the cooler weather >70° without great fear of overheating as long as you don't have a trailer behind you. Be aware that your defrost/AC won't work unless you're moving because there will be no draw across the coils when you're still now.

 

[GB1982]

Yank your fan off and drive it around without the fan. JL brought up a rather good point that it might be the the EBPV that you're hearing as it has a similar sound to a fully engaged fan clutch. You can drive around without the fan in the cooler weather >70° without great fear of overheating as long as you don't have a trailer behind you. Be aware that your defrost/AC won't work unless you're moving because there will be no draw across the coils when you're still now.

Ok he said it right. It is the coldest in a while. Winter time its NOT doing it. My truck does it middle of the summer. I mean even hot as hell outside the fan should not kick on that much going down the interstate? The EBPV releases like it should at idle when brake is applied.

 

[BJS]

if it is not doing it in the winter then you have a bad fan clutch.

EBPV actuation not tied to brake application it should cycle at start-up and when extremely cold it will close to help warm up the engine but should open once you hit the throttle

 

[JLDickmon]

Ok he said it right. It is the coldest in a while. Winter time its NOT doing it. My truck does it middle of the summer. I mean even hot as hell outside the fan should not kick on that much going down the interstate? The EBPV releases like it should at idle when brake is applied.

"hot as hell outside" it very well MIGHT cycle going down the interstate... it all depends on how hot the air is blowing on it..

however, I'd still have to tell you to take apart the stack and clean out any and all debris in there first..