I have noticed lately that my high speed fan seems to come on a lot.

Using Edge tuner I watch the temps and are always within delta 15, more closer to delta 8 degrees. Put in a new Bulletproof egr cooler last year, new egg valve this year.

Driving around the other day it was 78 degree F out side pulling my 30 ft trailer.
ECT was around 212
EOT was 220 ish
Trany coolant was 187
Think it had about 20 psi boost at the time
Rad fluids all changed last year and still full, no burping.

The high speed fan kept coming on. This did not seem to occur previously. Might just be me, but is this normal.

Should I be looking at something somewhere ? I just don't recall it coming on so much at the cooler outside temperatures while pulling the 5th wheel.

Also, I pull a 5th wheel and I am considering a dirt bike carrier and a front receiver for the truck. Then put the 1000 lb rated dirt bike carrier on the front of the truck and place a couple of dirt bikes on it. Bikes range from 150 lbs to 230 lbs, I think it will be ok with the steering. I will be well within CGWR(Combined) for the truck and 5th wheel

I am building an extension to the back of the 5th wheel to carry two dirt bikes back there as well, for a total of 4 bikes. Might end up 3 on the back of the 5th and one up front the truck. Need to be careful of the tongue weight at the 5th hitch. Can't have to much weight behind the 5th wheel axles or my 5th hitch may bounce. Again well within the GVWR of the 5th wheel.

My concern is blocking air flow into the rad/grille with the front bike(s) and constantly over heating the 6.0L

Has anyone had experience carrying dirt bikes or anything else on the front of the truck ? Heard of a guy burning out his trans from a front mounted tire, but that is more solid and likely mounted closer to the grille.

I could build an air dam around the bikes, but think thats just more crap on the front of the truck.

Comments are appreciated.

 

Since I put in the SGII, I watch the Fans speed while towing. Trying to learn where and when it comes on.

I was pulling my TT one day in the city and could hear it at certain speeds, that I didn't really notice before.

I also thought, at the time, that the fan was increasing speed more than usual. I had my tow/haul on and I think, not for sure on this, that while in tow/haul, the fan increased more at the same temps (ECT) than with it off.

Don't know for sure, but I think that is what I was seeing.

 

Are you sure you are having the high speed come on, there is a low, medium and high. At those boost, you are pulling pretty good, so I wouldnt be surprised if medium is on most of the time. When you pull a hill high should come on for sure. I dont think this occurs on mine until 219 degrees ECT is indicated on my outlook monitor, then she howls and eventially off, sometimes even on the hill still. As long as the bikes are far enough out from the grill so air can get around and through I dont think you will have a big issue. Might want to consider smaller bikes in the front so you are not blocking as much radiator. Make sure the rad and all your coolers are clean, they shhould be backflushed and you should have a small plastic bug screen behind the grill in front to stop the bugs from plugging things up. The bugs stick to the plastic window screen, dry and fall off, this way they are not lodged in the rad. This is a bit of an old farmers trick, but it works, as the more radiator passages are blocked, the less cooling you have. I am thinking your comments may mean you are already partially blocked if in fact you are truly running on high fan speed a lot, as mine rarely goes on high except on 7% plus grades with trailer and full load in truck.

 

Thanks Mike,

I am going to watch it more, plus try and blow out the rad from the back with an air hose, soft brush or pressured water. Carefully!!! I don't recall the high speed fan coming on so much this last year, so my 'spidy senses' are telling me something is up. It is the high speed fan because its noisier that heck. I always get concerned when that fan comes on.

I am going to watch the temperatures more as well.

This has been a concern with wanting to carry bikes up front.

Thanks for the comments

 

Driving back into town today pulling my fifthwheel my instrument panel beeped and there was a note that said, check engine temperature. I was climbing a long hill.

My factory temp gauge was off the top. My Edge tuner said 244 and went as high as 250 in a few seconds. Pulled over and let it cool down.
Under the hood the coolant all looked good. Nothing boiling over.
This has never happened before.

I could not hear the high speed fan cutting in when driving. Fan was running when stopped.

Normally the high speed fan cuts in about 225.
I Don't recall hearing it cutting in.

As i Was near the crest of the hill and The Truck cooled to 240, i decided to drive again. See if it would cool. Cresting the hill and driving down hill now or on flat land the temp dropped to 220. Which is ok.

I drove a bit slower and had flat land all the way home. So truck and Fifthwheel are home.

I am thinking that because the instrument panel beeped that all temp sensors are ok and that i have simply lost the high speed fan function in the fan itself. Is there anyway to test the fan's high speed mode?

I am thinking just replace the fan.

I will also check codes tomorrow.

Thoughts ?

Thanks for your help in advance.

 

Sounds like the fan clutch is bad, not the fan.

 

Thanks I will check that out as well.

Still need to pull the codes. It will be next week before I can look at it.

 

Is your EGR connected, depending on year of truck, without EGR connected, I think you will have different fan operation than stock. My fan comes on high at indicated digital temp of 217, I think you need to monitor fan var and see what is being commanded versus what is actually happening. I also wonder if your ECT sensor is going bad, can you swap with oil or at least check temp at cold start up see if they match ambient temp within a few degrees. I have never really seen over about 223 d f on the coolant, certainly never that high as 250. Did you put that motorcycle carrier on the front?

 

Agree with the others. My high speed clutch engages at 219 and I can see it going up to 224 or so then right back down to 215 or less when towing.
I also agree with Bryan, check your fan clutch sensor as the fan noise you hear is the same fan, only engaged fully.

 

A bad etc sensor could be reading low and causing the fan clutch to lock up because the pcm is reading higher ects than they actually are.

Shack the ect after an overnight soak. It should be close to ambient and close to the eot. If it isnt, you know it's bad. If it is, that doesn't mean it isnt, bad when temps increase.

I don't know how you check the accuracy of the ect sensor other than installing a known good one. The Eot and ect are the same sensor. I guess you could swap them if you clean them up real good.

 

Thanks guys great input. No i never put the motorcycle carrier on the front. Just thought that was a bad idea for a few reasons. Including having to clean grasshopper guts off of the bikes all the time. Haha

My EGR is connect.

I am certain that my high speed fan kicks in at 225 as indicated on my Edge Tuner. Fan is noisy and you can definitely hear the high speed kick in. The only time the high speed fan ever goes on is when i am pulling the fifth wheel up larger hills. I don't intend to pull anything far enough to get to those hills until i get this fixed. Its a few 100 kms . So while it would be nice to test, i don't want any issues out on the road anywhere.

The think i find strange is that the truck has never been that hot before or say it was that hot and i have never seen the info screen come up and say ' Check Engine Temperature'.

It said it reached 250, but to get out and look at the truck under the hood, nothing seemed different. I was expecting at that temp to see water bubbling back into the splurge tank. But everything looked normal.

So i am suspicious of the sensors.

I have had no time to look at the truck it has been in the driveway since i got back. Am going to look at it this weekend and read the codes and maybe just buy a sensor and swap it out.

I honestly expected at 250 to see it boiling over into the splurge tank. The truck also seemed to be running fine.

I will post back here what i find out this weekend. Thanks for the tips.

 

Lots of discussion out here about the OEM coolant caps and their poor psi holding capacity. I recently changed my original out to a new Stant unit after seemingly losing some coolant. My egr is totally dry so it's not going down the egr cooler.

 

OK,

Looks like I am throwing a few codes.

P0480 Fan Control Circuit - Fan Control Relay
P0528 Fan Speed Sensor Circuit No Signal

That would seem to suggest to me that this is an electrical thing causing the high speed fan to stop working. I am going to check the wiring on the plug to the Clutch fan assembly. I think if the clutch fan itself was not working I don't think this would show up as electrical related codes. Probably just over heat with only a high temp code. Funny. I didn't show a high temp code. That seems strange to me.

I read the codes and thought I would just go out and buy new sensors and install them. However, nobody, NAPA or AutoValue has a part listing for either of this sensor or relay. Cannot see them being OEM only, so I am right now, assuming they are part of the clutch fan assembly. New clutch fan was priced out @ $460... ouch ! Thought I was buying a $14 sensor or two ...


I have a few other codes that I believe are non-related.

P0341 Crankshaft Position Sensor
- I saw this one before, it has come back
- will have to check the wiring on this one

This wiring ( assuming its up top on the cam or something) and the fan stuff could be up on top of the motor in the same area. Maybe that dam squirrel packing pine cones under my hood on top of the engine chewed some wiring.


P0500 Vehicle Speed Sensor A
- will have to check the wiring on this one
- this is a new code



P1876 Transfer case 2 Wheel Drive Solenoid Circuit failure
P1832 Transfer case differential lock-up circuit failure
- these are new
- This sounds like a bad ground off of the transfer case, as I doubt both sensors went at the same time.
- shifts ok


also..these three

U1900 CAN Communication Bus fault
B1352 Ignition Key in circuit fault
U2023 - seems to be related to a no start.
Just before I read my codes, I had the key in the ignition for some time setting up my reader, then tried to start the truck and had a no start scenario. Would turn over but not start. No fuel ignition at all. Shut off the key and then turned the key on and it started just fine with a few cranks and its all been good since then. So I think something just happened there with the key in with the ignition on for so long. Maybe the glow plugs cooled off to much. Not worried about these last three codes.


Thinking I need to check some wiring around the truck.

 

That's a whole lot of wiring codes. I'm fighting the P0500 code myself and it's not the sensor but I've not been able to get the wiring diagram for it. Check all the connections on the driver's side fender well closely. The fan circuit codes are usually a cut harness from the fan shroud over to the motor and be sure to give the fan a wiggle to see if it's "loose" which could indicate a water pump problem.

 

Ok, i had a look at it on the weekend.

"Give a wiggle to see if the fan will move" not sure what you mean. But i can turn the fan blades. Should i be able to do that? I am thinking yes. I am thinking the fan just spins free until it heats up then the clutch fan engages. Then when it gets too hot the fan turns on the high speed fan electrically and spins the fan faster than the clutch fan is spinning. Is that how these work? Mechanical clutch with an electric side?

Took the truck out for an hour drive. It heats up driving around the city, get up to 210 and i would not let it get hotter, not normal, so high, so
I hit the highway and it cooled down to 192, in the evening had it cooling down to 184 from 210.

So water pump is working and the rad is working in an air cooled mode. But not enough air is pulling through the rad to cool the coolant at lower speeds or higher load climbing. It over heats.

So if the fan is a clutch fan that comes on mechanically when it heats up, it tells me the clutch fan itself is not working or engaging the mechanical side because it is not pulling additional air through the rad to cool the coolant at lower speeds in the city. That is if the clutch part is mechanical only.

If the fan is totally electrical, either the wiring is toast or the fan motor has failed, or i guess a sensor that runs it all could be failing.

Can someone tell me exactly how this fan works please and thanks.

Also is there a kit to rebuilt these clutch fan ? Vs. a new non oem clutch fan for $480 ?

Thanks

Kev