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Man of endless projects
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Discussion Starter #1
every time i take my truck offroading, even lightly, it has a horrible tendancy to overheat. onroad is perfect due to airflow but offroad lasts a few minutes then im sitting waiting for it to cool enough to refill it with water. i use to never overheat but now im curesed. i have replaced the radiator, radiator cap, checked hoses, replaced t-stats with a 185 and 165, replaced waterpump twice, done a few flushes, taken out condensor for better airflow, bought heavy duty fan clutch, replaced timing chain, and probably a few other things i cant think of. still cant get rid of it. any other ideas will help.

also i have a EGR bypass (its my offroad only truck and im in florida) on. since the hot gasses wont heat my intake anymore, does the throttlebody still need the cooling hoses? seems like it would only heat the intake and cause lose of power.

do electric fans on the front really help noticeably? should i take the fan clutch off and have it fixed on?

i really dont want to keep throwing money at this problem but any help to kill this problem will help
 

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Roller rockers are gay
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have you tried testing the ECT (engine coolant temperature) sensor for proper resistance? search in Steve83's (a member here) supermotors. there is a chart for the ohms there.

have you hooked up a mechanical coolant gauge to see what the temp is actually reading?
 

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ever get a coolant smell in the truck? condensation on the windshield often? sounds like the only thing in your coolant system you havent replaced is the heater core. I had the same problem, It was fine on the road but as soon as the revs went up without the airflow when offroading it would get hot. check it out. either that or your timing chain cover gasket. have a peek at the timing chain cover to see if its leaking. only things I can think of that would cause coolant leaks other than the rest of the stuff that you say youve replaced.
 

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i have a similar problem, but on the street. mine doesnt over heat but runs towards the warm side. only when i go up hills then drops when i level out.i think its cause i have 35's with stock gearing. i just got it so i still got to tune it up and regear it. im thinking 4.56.
 

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3g alternator and electric fans
 

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Man of endless projects
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Discussion Starter #7
i repalced the heater core about a year ago and doesnt show symptoms of it being a problem. ive dont the timing chain cover twice due to a broken gasket. i dont have any leaking and the system seems to have pressure like it should. every time i go offroad, i have to add the 2 gal i carry in the back because it all boils out of the overflow. but other than that, onroad i never have to add any.

no i havent tried the ECT yet, ill try it out when i can find where i put my multimeter
 

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maybe take it to a shop that can pressure flush the system, maybe you have a partially blocked coolant passage somewhere thats just not flowing enough.
 

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is the water pump the correct rotation waterpump ive gotten standard rotation water pumps b 4 that were in a reverse rotation box..
 

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Some assembly required!
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I had a similar problem with mine wanting to overheat when I went crawling around in low range. I didn't try most of what you did, however I did solve the problem by going to the junk yard and getting a pair of smaller electric fans and installed them as pushers, leaving the stock mechanical fan and shroud in place. I picked these fans in particular because they had metal surrounds instead of plastic, and they had guards built into them. One came out of a Geo Tracker and the other out of a Mazda MPV, that being the smaller one. I run both of them off of a manual switch on the dash, and they are powered off of ignition power rather than hot power so I can't forget them and kill the battery by leaving them on. Due to the added thickness of my additional power steering and tranny coolers my grille doesn't fit on there anymore, but it looks just fine to me with that big winch bumper covering everything up. I know it's a little ghetto for some folks taste, but it works like a champ and definitely solved the problem.







 

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Man of endless projects
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Discussion Starter #12
ya i was starting to consider electric fans as my next option. my fan shroud is all broken to hell so i need to replace that with one from a junkyard and find some fans while im at it. new shroud and pusher fans and i bet ill be the coolest one out there lol. since i already took my a/c condensor off, i should have plenty of room but i did add a tranny cooler and loudspeaker in its place
 

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Hey if your shrouds help direct the air flow to the motor ,and pulls air from the radiator I bet that is your problem .Cause when driving down the road the air it being pulled cause your speed, but off road high rpms and not having good air flow could be the problem. And your thermostat being under spec might not help. Cause your t state opens when coolant gets warm but closes when it gets cool. This give time for your coolent in the radiator to cool down so when your t state opens the coolent flow into the motor and cool it. If your t stat stay open cause of low opening temp it all just circulates and doesn’t get a chance to cool
 

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Man of endless projects
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Discussion Starter #14
hmmm thats a very good point bout the t-stat. my shroud is bad but it should still be doing its job. but every time i go over a big bump, the fan will hit the shroud and take another chunk of it out.
 

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If your shroud is missing big chunks than the fan can't draw cool air through the radiator as well, which you will notice at low speeds, cause ther's less air being forced through the front end. Get or make yourself a shroud that will work better and try putting in the thermostat that's recommended for your application. A lower thermostat can help in some circumstances if you keep it close to what the original is, if you go too much the stat will never close and therefore your coolant will stay warmer. 20 degree change is quite a bit, I never go more than 10 degrees lower than stock. Make sure your whole system gets flush out really good also. This could easily be caused by multiple small problems.
 

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Are you sure your fan is pulling the air from the radiator? Are the blades correct for the water pump rotation?
 

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Man of endless projects
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Discussion Starter #18
the stock waterpump was apparnly a reverse rotation waterpump because it went on the flat side of the serpitine belt. the new one, im not sure which direction it is so ill have to look at it tomarrow to tell but i htink it is the same. the head gasket seems fine cause the i have strong compression in all cylinders and the water in the radiator is clean. no signs of it blowing out the exaught either.

ya the fan shroud is beat up allitle but it doesnt look in that bad where it would overheat soo badly. ill still replace it tho. anything good to make one out of? if not ill jsut go to the junkyard.
ill also get some electric fans while im at it. if i still have a problem then ill try the t-stat but it was still overheating when i had the stock 185 in it. hell it was still overheating with the fan shroud is almost new condition.
 

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QUOTE"(Decided to replace the thermostat and the little hose coming off the fitting as a bypass.

I discovered what I thought was a reversed thermostat. Parts store and and old ford book I found proved that the thermostat was installed backwards.

I have no idea how long this was this way? I have no idea how many 6 packs were involved? BUT I tested the old thermostat and it was still working but backwards. I replaced it anyhow with a new one I also tested in a pan of boiling water and a new gasket. EUREKA. That was all it took for now. Operating even with the AC on in 90+ FL weather at 5/8th of the temp gage.)"

From the mustang site FEP which im a member of ...Just a thought..
 
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