Alright, here is a problem that has been bothering me for the longest time and has cost me money. Whenever i drive my truck for any distance or time, when i get out it smells badly of antifreeze, yet no dripping or overspray, and the truck feels extremely hot and stays hot for a long time afterward. I've had the thermostat replaced atleast twice, and i did it myself once with a 185 stat, and no change. Twice my engine has blown its load and once had to have it's radiator replaced with a stock style, not my choice, and i believe the water pump has been replaced also. I even went out of the way and cleaned the entire coolent system, radiator through pump to firewall and back around, and still no results. The odd thing is that when we first got the truck it ran very cool (no movement in temp gauge whatsoever) even with ac on high(lovecd it). Now it sits at the start of low on gauge and will got to mid level when ac is on during street driveing but go back to low when on freeway. Has anyone experienced a situation like this, should i replace radiator again with summit racing style or what. I have yet to overheat this summer so i shouldn't complain that much but it is just annoying as hell.

 

It kind of sounds like the fan clutch isnt functioning the way it should . What model yr & mileage on the truck ?

 

its an 89 150 300 and its got around 95"ger" for milage.

 

Even with the A/c on , On summer day , the coolant temp shoudlnt go much over 200 deg . Fan clutch failures , esp the age & mileage of your truck are common . If you look at the front of the fan clutch & see an oily residue on the bimetal spring thats a pretty good indication that the fan clutch has failed & isnt locking up when the engine needs more air thru the radiator . If you have no leaks in the cooling system , the radiator & A/c condenser are clean , no bugs or other debris , then its likely the fan clutch is the problem .

 

where exactley is the fan clutch on an 89 150? I've heard that term dropped by lots of people but have no clue what and where exactly it does and is located. Also to replace one, about how much is the unit and is it a simple bolt in and out type job or will i need to go to a local monkey. I have mild experience working on truck (have changed oil, removed disassembled polished and put back together throttle body, have cleaned coolent system, have removed and replaced thermostat) so would it be something that i could handle or is above and beyond me? also, are there aftermarket fan clutches that are better than stock or should i stick with basic replacement? Thanx

 

[font size="1" color="#FF0000"]LAST EDITED ON 08-Sep-01 AT 03:13 PM (EST)[/font][p] The fan blades are bolted to the fan clutch . On the 300 it screws onto the water pump & will require the use of a tool designed to remove it , It is a reverse rotation fan & the threads on the fan clutch are right hand thread . The front of the clutch has a bimetal spring that reacts to heat . When hot air is pulled thru the radiator & a/c condensor , its cause that spring to coil up , this opens passages inside the clutch that allows a thick fluid to lock the clutch so that it turns roughly the same speed as the engine , all its doing is turning faster , pulling more cooler air thru the radiator when its needed , usually stop & go traffic or slow speeds . Once you reach hwy speeds enough air is flowing thru the radiator , the bimetal spring cools , closes the internal passages & the fan slowly disengages . It helps save a little on fuel economy because the engine doesnt have to turn a fan thats locked all the time . Signs of failure of the fan clutch include an oil residue on the bimetal spring , an engine running hotter than normal at slow speeds , plus when the fan clutch is locked up , the fan noise is considerably louder . I replaced mine when it died with a Hayden model simply because the ones I got from Ford ( 2 of them ) didnt work any better than the one that died . They seem to make quality cooling system parts . I paid about $40 for it 4 or 5 yrs ago .

 

Some guys don't even bother with the fan clutches and put an Autozone flexfan on for $25. -something to think about.
BUT, what strikes me, is that you said it ran cool when you got it. If that was not to terrible long ago not much should have changed. I've talked to some who've run into the problem of overheating from running the carbureter too lean. - Another something to think about.

 

well i have had the truck since like early spring of 98, almost 5 years ago and my truck is efi so i don't think it should be a problem with carb cause i thought that efi don't have carbs persay. thanx for help anyways.

 

what if the fan doesnt engage at all, is this a result of a bad fan clutch or is this something new. I was wondering cause i don't remember if the fan came on or not. just an idea

 

[font size="1" color="#FF0000"]LAST EDITED ON 11-Sep-01 AT 01:29 AM (EST)[/font][p]Here is a thought.....check for a restriction in the Radiator. Start the truck....grab the upper hose and feel for when it get warm...(when the thermo opens) and then feel the lower hose...it should get warm as well not too much longer after the upper. If it stays cool for a while...you might need a new radiator.....i know the lower hose is going to be cooler...but 150 to 170ish is still hot in my book! You are over flowing so you are gitting hot....Definatly check the clutch...one test i heard of...not sure if is legit...but what you can do is spin the fan...if it spins freely or a couple of time...its time for a new clutch. At cold temps that fan shouldnt spin easly. You have get a big a$$ wrench to brake it loose...do it with the belts on and hit the wrench with a 3 pound mini sledge....makes it easer. If its been a while...might want to put in a new thermostat as well....they can stick....let us konw what you find.....

Dan "Mudinford" MacDonald

Rather be pushing a Ford than driving a Chevy.

Like A Rock......In Water!


woops! just saw that you have replaced the Rad...but even the new ones can defect.......just a thought