1996 F150, 302 cooling problem

[Jetmec2k]

I have a co-worker at work who wants to trade my 99Ranger2wd3.0 for his 96F1504wd302. The thing is there is no mechanical problems with my Ranger but there is a coolant problem with the F150. The coolant problem is that the truck will warm up to the M of NORMAL on the temp gauge, then drop to the O/R range of the gauge then raise back and forth. The truck does not over heat, but is this fluxuation ok/normal? In my 86' mustang 5.0 it steadies itself at the O/R range of the temp gauge. My friend has changed the thermostat (dosent remember the temp range installed) and the temp sensing unit. What do you all think??... Thank you for your input and time...

 

[offroadkarter]

Did he replace the temp SENSOR or SENDER. There is a difference. The SENSOR, which is on the crossover tube is for the ECU. the SENDER is for the gauge cluster. I'm drawing a blank on where it is, yet you have a 302 and my bronco has a 351. I replaced the sender on my friends 302 explorer and it was on the lower intake.


You'll think I'm an idiot for even suggesting this, but try unplugging it and plugging it back in. On my bronco, my temp gauge would fluctuate like you described. (mine was actually worse, it'd drop almost to C then shoot back up to O) I replaced what I thought was the sender, but turned out to be the sensor, and the gauge just died. So I left it for months, until me and a friend started poking around and we found out the sender was actually on the lower intake. So I unplugged it, plugged it back in, and it has worked perfectly from that day on, its been about 2 months I just cleaned the contacts for good measure.

You can also test to see if its a bad gauge, by taking the pigtail plug for the sender, and grounding it to the engine, and turn the key to on. If the gauge immediately spikes to H, then its a bad sender. If it doesn't respond then its a bad temp gauge...


hope this helps :beer:

 

[hotcobra03]

i have an 1995 f150 4x4 with 5.8...

i would read service manual for understanding and repair...they are hard to find..ive came across a helpfull link for 1995 ford info on trucks ..it also has about everything else you could dream of..

i just also came across this pinpoint test section where you might find a way thu it for help..i just found it and havent searched but clicked around to see highlighted items go to that page/section

1996 Bronco/F-Series

main link to use for searching
Ford Bronco And F-150 Links - PARTS SOURCES - Including FREE BRONCO SPECIFIC PARTS CATALOGS!

i just now looked found backdoor into manual..
http://www.thedieselstop.com/faq/9497faq/maint/stj/leftside=stjs440l.htm&rightside=stjs440r.htm

 

[5.0Flareside]

could be as simple as the sensor is twitching or that the thermostat is at times sticking closed and then it forces open finally which is why you see that temp drop.