dgrov3r Posted August 3, 2011 Report Share Posted August 3, 2011 So first of all I think I am doing something wrong when using the search feature because I know there's already been a thread on 85% of my questions but I can't seem to get the right results.. Anyway my truck is mechanically stock and always runs at atleast half way (210) sometimes a little past and every once and a while 3/4 of the way to RED! I know running it hot can do serious damage. Anyway, a member told me to check out the clutch fan assembly which I have yet to do. Has anyone else ran into this and what was it. Also I am wondering what the E-Fans are all about and if the fans and or a Tstat can help my problem after it's fixed to prevent it happening again. The truck is an 03 with 123k Thank you for your help. Quote Link to comment Share on other sites More sharing options...
Raffailo Posted August 3, 2011 Report Share Posted August 3, 2011 Tru-Cool MAX transmission cooler *without external cold weather thermal bypass Makco Transmission Parts mine doesn't get as high but everyone recommends replacing the tranny radiator which i will be doing soon. Quote Link to comment Share on other sites More sharing options...
zachm89 Posted August 3, 2011 Report Share Posted August 3, 2011 i think he is referring more to the vehicle coolant rather than the tranny fluid temps. anyway, if the stock fan clutch is bad then that could be causing your over heating problems. the best way to fix it and fix it for good would be to install a 160* thermostat with a set of electric fans. which coincidentally, if youre interested, i have some fans for sale. for a full clutch fan to efan conversion you will need 1. fans from an 05+ truck/suv 2. harness to run the fans from the pcm 3. custom pcm tune to control the fans...and like stated at cooler thermostat is always a good idea as well! Quote Link to comment Share on other sites More sharing options...
jtmarine02 Posted August 3, 2011 Report Share Posted August 3, 2011 (edited) In my opinion 160 deg stat is fine, but a 180 deg stat will do just fine. Electric fans is the way to go, I have the HPM dual fans that I picked up off this site and my temperatures dropped quite a bit. I live in West Texas where as of lately the temps are over 100 and my trucks temp stays constant at 190. The fans make a difference however, you could have air trapped in the coolant system. Do you know if it has been serviced lately? Another reason for the over heating could be a bad termostat (rarely happens) or debris in the radiator/ coolant system that can cause a blockage of flow therefore creating a higher operating temp. Edited August 3, 2011 by jtmarine02 (see edit history) Quote Link to comment Share on other sites More sharing options...
BlueAKSSS Posted August 3, 2011 Report Share Posted August 3, 2011 If you cluster has never been replaced it could possibly be a bad stepper motor. On another car I have I was questioning the gauge so I bought an inferred thermometer for $29 bucks at home depot, opened the hood and checked the temp of the coolant at the thermostat housing. Quote Link to comment Share on other sites More sharing options...
Cramer Posted August 4, 2011 Report Share Posted August 4, 2011 If you don't know if the coolant has ever been changed, or the thermostat replaced I would do a cooling system overhaul. Start off by having a shop do a complete cooling system flush and fill with the green antifreeze and a bottle of water wetter, Royal Purple purple ice, or any good coolant additive. At the same time the coolant is flushed replace the thermostat with either a stock replacement or a 160* unit. If you decide to go with a 160* t-stat you will need (should get) it tuned. If your budget allows it at the same time would be to swap to electric fans. Like the ones Zach has for sale is what you would need. You would need to tell the tuner to turn on the e-fan functions so the PCM can take care of the cooling. You may or may not need to replace the alternator with a 145amp alt to be able to provide enough power for the fans and other aux functions but alot of people keep the 105amp alt with no problems. If you don't have the budget for the e-fan conversion, i'd run to the junk yard and get a clutch fan from a lower mile truck and put that on. To me it sounds like your clutch fan is the culprit as a faulty gauge would be more eratic on the readings but it would be a good idea to have a shop or someone with tuning software to hook it up to a scan gauge to see what the actual temp the pcm is reading. My gauge is about 8* off from my actual temp through my scanner. Quote Link to comment Share on other sites More sharing options...
misterp Posted August 4, 2011 Report Share Posted August 4, 2011 First determine exactly what/where the cooling issue is: The truck's ECT is designed to operate about a needle's width or two below "straight-up" (195-205) at freeway cruise in the summertime heat. STEP 1 - If the truck overheats at 50+ MPH, then the radiator and/or engine coolant is not working right. The truck is supposed to get a complete coolant flush/fill service at 100K-miles, if this has not been done then you are driving on the factory 8-year old coolant. I would also advise, this might be a good time to splurge $7 and replace the engine coolant temp sensor, since the motor's cooling jacket will be emptied and it's easy to reach; also make sure you burp the air out of the system before driving the truck. STEP 2 - If the truck runs fine at freeway speed but overheats when parked, then the radiator is not getting enough airflow, i.e. the mechanical fan clutch is shot. Fan clutches do not last forever, I would not expect more than 75K-miles service out of one. If your truck still has the factory fan clutch at 120K+ miles, I would strongly encourage replacing it. Another much more expensive repair option is to ditch the mechanical/clutch fan system and use electric fans instead, good ones work great but at a cost of hundreds of dollars E-fans are more of an 'upgrade' than a 'repair'. When servicing the cooling system, USE THE CORRECT FLUID or you WILL F-up your engine *quick* - research and make sure you are using DexCool. Also replace the belts as well, they are not meant to last more than 60-75K miles at best and this would be a good time to inspect/replace them if necessary. About the dash gauge - yes it is possible the stepper motor of the gauge could be defective, but I have not seen a temp gauge do this yet; I would consider that last on my list of diagnostic tests. But if you want to make sure, a good cheap way to verify is to get a $6 hand-held infrared temp sensor from Harbor Freight and measure the temp of the upper radiator hose, and end-tanks of the radiator itself - that will probably give you a very clear idea of just exactly the temp the motor is operating at; you can get a nicer infrared gun at Home Depot or Sears for $90-100 but the tiny one I got from HF works really well. Also, some volt-ohm-meters will have thermocouples and can measure temperature (I have a Fluke that does this) - my point is that you might ask and one of your buddies may have a diagnostic tool you can borrow to quickly verify that your temp gauge is correct. Mr. P. Quote Link to comment Share on other sites More sharing options...
dgrov3r Posted August 8, 2011 Author Report Share Posted August 8, 2011 The fan clutch motor spun pretty freely when the truck was off so I replaced it and it runs at about 195 now. I plan on flushing the system and getting a 160* Installed at the same time as my intake just waiting to splurge on a tune. Anybody heard of REVOLUTION TUNING in Hampstead NH? I know its a longshot.... Thanks for all the very good help Quote Link to comment Share on other sites More sharing options...
matt 2k12 Posted August 9, 2011 Report Share Posted August 9, 2011 From what I have learned over the years, electric fans should be a supplement, not a replacement of your belt/mechanically driven fans. If your vehicle is overheating, there is a problem with the coolant system, plain and simple, and no amount of upgrades or gadgetry is going to fix that. Repair what came from the factory, then worry about upgrades. Quote Link to comment Share on other sites More sharing options...
gmJake Posted August 10, 2011 Report Share Posted August 10, 2011 The idiot I bought my truck from actually had the efans wired in backwards so the fans were pushing instead of pulling. Sometimes ya gotta wonder Quote Link to comment Share on other sites More sharing options...
Cramer Posted August 10, 2011 Report Share Posted August 10, 2011 From what I have learned over the years, electric fans should be a supplement, not a replacement of your belt/mechanically driven fans. If your vehicle is overheating, there is a problem with the coolant system, plain and simple, and no amount of upgrades or gadgetry is going to fix that. Repair what came from the factory, then worry about upgrades. So your saying that GM didn't mess up when they put clutch fans on the trucks, then in 05 started putting them on the trucks? And by supplimenting the use of the electric fans along with the mechanical fans is when you know your having problems. Electric fans are more economical and practical than clutch fans. Hence why GM put them on the 05's. Spend $350 for electric fans now and benefit from them or spend another $100 on the clutch fans again. His problem with the coolant system led to the clutch fan being faulty. That can easily be fixed by upgrading to efans or replacing the clutch fan. That is plain and simple. Quote Link to comment Share on other sites More sharing options...
matt 2k12 Posted August 10, 2011 Report Share Posted August 10, 2011 So your saying that GM didn't mess up when they put clutch fans on the trucks, then in 05 started putting them on the trucks? And by supplimenting the use of the electric fans along with the mechanical fans is when you know your having problems. Electric fans are more economical and practical than clutch fans. Hence why GM put them on the 05's. Spend $350 for electric fans now and benefit from them or spend another $100 on the clutch fans again. His problem with the coolant system led to the clutch fan being faulty. That can easily be fixed by upgrading to efans or replacing the clutch fan. That is plain and simple. I don't portend to know everything about these trucks. I just know about vehicles in general. And I know on a high performance application, a belt driven fan will always cool more efficiently than E fans. Quote Link to comment Share on other sites More sharing options...
dgrov3r Posted August 12, 2011 Author Report Share Posted August 12, 2011 I didnt have the funds for efans yet but i appreciate all the input. Put an new fan cluth assembly in and the truck seems maybe 5* cooler? Still always over 200/ The clutch fan did not spin freely when truck was off now it has resistance Quote Link to comment Share on other sites More sharing options...
shadowsniper3006 Posted August 12, 2011 Report Share Posted August 12, 2011 (edited) I don't portend to know everything about these trucks. I just know about vehicles in general. And I know on a high performance application, a belt driven fan will always cool more efficiently than E fans. I have to ask were you are getting this logic. The e fans provide more cfm of cooling then a clutch fan and are at a constant cfm level( or programmable level), not an rpm based level. I can also tune my fans to come on at what ever temp i so choose and go off at what ever temp i choose, not based on the air temp that is blowing past or around the clutch fan. I can also program my fan or fans to come on with a certain ac pressure as a fail safe. I can also have my fans stay on when the truck is shut off if the temp is above a settable point, and set a time limit for which they stay on, and in addition i can also add a manual switch and leave the fans on(and is some cases an electric water pump) to cool the motor while its not running, of coarse not available with a clutch fan. And on top of it all, the e fans only put a slight load on the alternator where as the clutch fan can put much more load on the motor sucking more hp out of it, to the point where a lot of the old school hot rods run a electric motor on the water pump/fan so its not crank driven and adds the ability of the cooling when the motor is off. Edited August 12, 2011 by shadowsniper3006 (see edit history) Quote Link to comment Share on other sites More sharing options...
Cramer Posted August 12, 2011 Report Share Posted August 12, 2011 Quote Link to comment Share on other sites More sharing options...
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