Hey all,

I noticed yesterday after comming home from a 40 or so mile trip towing the boat that the fan had come on for a bit. I am not towing a huge boat here its a 19' probably weighs in at 4k with the trailer and full of fuel.

The situation:

The fan hadnt come on at all while toing either on the way or or the way home. I stopped after towing, mostly 45mph with occassional 30 & 55 mph zones, at the local sandwhich shop and left the truck running with the wife and pup in the truck for maybe 7-10 minuites. When I pulled away the fan came on for maybe 500 feet or so and then shut off. It was about 80-85* or so. I am hoping that you guys will tell me this is normal and not to worry.

I am not loosing coolant, I dont smell coolant, and the truck never pukes (Knock on Wood). I hope this isnt bad karma for me starting that darn haapy thread last week.

Anway I took the truck for a short ride early last week to pick up some parts for a job and it did the same thing too. It was 85-90* with high humididty when it happened.

Hopefully all is well with the truck.

One last question, now that I am paranoid I am going to buy a coolant guage, where should the sensor go to and at what temps should the truck run, and when should I worry. I know the truck will defuel but I would like to prevent it if I could.

Sarge

 

Sounds normal to me. Make sure your coolant level is at the MIN mark, no higher. Also, be sure the radiator is free from leaves, bugs, etc. An easier but more costly option than a coolant guage is an Edge Attitude monitor or a Scanguage, both of which you plug into the OBD port under the steering wheel and you can monitor several different functions at once. I have the Edge Attitude so i can monitor Coolant temp, oil temp, voltage and trans temp on the same screen with only the one cord to plug in. Hope this helps.

 

sounds normal to me too buddy....

 

Yeah I dont want to get an edge just cause if I travel I dont need to hear how its chipped blah, blah, blah. I am going to get a Fuel pressure and coolant guage soon. I have a trip to PA comming up to move my cousin to NJ, so Hopefully before then but maybe not.

Sarge

 

The fan kicking on while towing wouldn't worry me especially if you were doing start-stop driving or going up grades. However, I've never had my fan kick on doing "around town" driving. This would make me think there was something preventing proper engine cooling, however if this was the case the fan should be running excessively while under load.

Have you looked at the DashDAQ? It's pretty expensive but will monitor almost anything that is available via the OBDII port. You can also program alarm setpoints for critical parameters.

 

Like I said it didnt come on til I was dragging the boat through the city for a bit. The a/c was on max and it was hot with 100% humidity. I am not going to worry too much about it cause normally it doesnt even come on. Like I said no loss or smell of coolant and the temp guage didnt spike, not sure that it would, but I am still crossing my fingers there are no issues as I am headed for about 1000 mile trip in 2 weeks.

Sarge

 

The Edge product I'm referring to is NOT a chip or programmer of any type. It is just a digital guage that can monitor your choice of several engine functions at once.

 

nothing to worry about here sarge. its normal

 

I just finished a trip up through Las Vegas and Utah. The temps were 105 when I went through. I had a small utility trailor loaded down and the bed full. I monitored the coolant temps with a scanner plugged into the OBD port and the highest I saw was 218 degrees. The fan never kicked on and the gauge never moved. I would get a gauge soon and monitor it. I can also look at air intake temps and saw it get upto 128 degrees.

 

yeah the factory gauge is more like a dummy gauge. it is not very accurate. from what I have read once you see it start to move it is too late. I think the fan dosent kick in till 220, at 240 you are probably replacing heads. the trans gauge is the same as the coolant more like a dummy gauge. I would recomend having analog gauges for these if you do any towing.

 

OK, here's some actual facts for you, instead of an opinion.

I have an EDGE insight, and I can tell you after my last trip that without it I probably would have come close to frying something. Personally, I would never have regular gauges.

During the summer here in Vegas, once the outside temp hits 85 deg, the fan will come on and off during the day, at very weird times, not seemingly related to engine temp. (Unloaded city driving) It will often still be engaged first thing in the morning, it will run for awhile and then cut off. There seems to be no "one size fits all" answer to when & why it comes on. This does make sense though, as the fan is not simply controlled by coolant temp alone.

Now towing is a different matter. On the open road the fan engages at 210 degrees, not fully engaged, just partially. As the coolant temp climbs, the fan engages more, until 213 - 214 degrees when it is fully engaged and will remain so until the coolant temp is back to 203 or less (sometimes all the way down to 195). On my truck it has been quite common for the fan to cycle on and off frequently. I know this because I just got back from a 2,400 round trip pulling a heavy trailer all the way.

Another observation is that if you can keep the truck in a top gear, the EGT temps will be high (mine topped out around 1,120) but the oil and coolant temps will climb very slowly. If the truck kicks down one or two gears, the EGT will be alot lower (around 950 or so) but the oil and coolant temps climb very rapidly. This is very interesting to me because the belief has always been that these engines love to rev over 2,000 rpms. From what I have observed, not so much. If I had to continue to tow heavy loads, I would definately be getting a stick.

Now bear in mind that this is how my truck runs, from what I have read on here, it seems that hey all run differently, some a litlle, some a lot.

I would not be at all worried that you have a problem, but do get gauges becasue my stock gauges didnt move at all, even when the coolant temp hit 220 and the trans hit 200.

 

x2 mine runs just like this here in So Cal

climbing long grades towing what have you seen your temps max?

my oil around around 240 coolent 230 trans 200 egt 1250...I saw these on the hwy395 from bishop to mammoth during 105deg outside temp about 45-50mph up the steep grade towing my 26' toyhauler...on the flats runnning 60-65mph it was coming on and off every few minutes and the temps were going up and down...oil was between 215-230 coolent was 205-220.

is it better to run in a lower gear and have cooler egts and faster moving oil and coolent temps or better to run in top gear and have the egts higher and the oil and coolent temps moving slower??

 

now to me that sounds pike there is something wrong with your truck the fan should not cnstantly cycle like that. Unless that is one heavy 26 footer. I have a 38' in the Texas heat and don't run near that hot at 65-75 mph.

 

I know the Edge you are talking about is not a chip...but today with the economy and the amount I travel I dont need to get to a dealer that see's that and says "Oh the Chip did it" even though its not a chip. I will get a regular analog guage as soon as I get some extra scratch.

Normally the fan will not come on unloaded unless I am in stop and go traffic and the A/C is on max cool. Towing the boat like I said it only came on after the truck sat and idled for about 10 minuites with the A/C on max cool and high ambient temps ith 100% humidity.

The route to get me to the lake does include some steep grades so I wouldnt be concerned if the fan came on.

Also when it did come on it ran for a short time, 500' or so, and not at full power.

Sarge

 

Towing in the conditions you described I'd be a little more concerned if the fan DIDN"T come on. I don't think you have a thing in the world to worry about Sarge. I would get the extra gauges though......just for peace of mind.