94 Ranger Heat Indicator Wandering

Hey guys!!
I have enjoyed all the info that I have managed to collect in this forum,so before I begin, I want to thank all for this forum,and the infor it contains.

Now to my current issue .... I just recently bought myself a used 1994 4X4 Ranger XLT ( 4.0 cu),and am really enjoying it... but as is usual for something this old, it needs a little TLC ... the heat hand in this unit keeps ranging from normal,all the way up to too hot, then back to normal. I have flushed the system really well, changed out the thermostat,and radiator cap to no avail, The engine begins very normal and as you drive down the road it runs in the normal range, then it'll begin to head up the heat scale pretty quick until it gets out of the normal range to hot .... then it'll just head back to normal ,and stay there a mile or two, then back up.
I am planning on looking at the clutch fan next ... the plastic fan has several cracks, so I am hoping I can find one of those too ....I would really welcome any advice that any of you guys ( or gals!) could offer... maybe ya'll have run into this very thing too ?
Thanks !

Could replace the coolant temp sensor. Also look into the fan clutch.

Thanks!

Thanks Sparky !!

I will definitely replace the fan clutch, and will look at the sensor ...... I am going to also try to find a replacement fan as this one appears to be cracked.

I appreciate your input !

buck2850 said:

Thanks Sparky !!

I will definitely replace the fan clutch, and will look at the sensor ...... I am going to also try to find a replacement fan as this one appears to be cracked.

I appreciate your input !

Click to expand...

Np. It would be nice to know if it was actually heating up or if the gauge is off. No way of telling... I dont think.

RE:Thanks

Yeah, I know Sparky .... well, I have picked-up the clutch,and fan from O'Reilleys, and will put it together Sat ... if the heat hand continues it's wandering ways, I think I'll go after an after-market gage,and check the heat with it ....

I appreciate your thoughts Sparky !!

My 4.0 did this once. Turned out to be a 20$ coolant temp sensor. Takes 5 minutes to change.

I ran into a similar problem in my 95 4.0l. After a bunch of testing, I found the waterpump had low flow and needed to be replaced. I had all the same exact symptoms as you.


Try this: while your driving and the temp going up above normal (catch it before it starts to drop), rev the engine up above 3000 rpm (to speed the flow of the pump). If the temp drops quickly then it s prob the waterpump.

A fan clutch wont affect cooling while driving at highway speeds. There is more airflow then the fan can pull. So if it still gets hot on the highway, its not the clutch.

Changed it all

Well guys, I took advantage of a pretty Sunday to just change it all ( water pump, fan clutch,and plastic fan blade for good measure)..... I already had changed the thermostat,and radiator cap after flushingthe system. ....I then took it for a good drive ..... so for that drive at least, and after the fan clutch oil got distributed, the temp got pretty stable, and we quit wandering .... thanks for all the help guys !!!!

Now, all I gotta do is find the source of a slight leak at the lower right side, bottom of pump. LOL !! here I go now re-tightening bolts !!!

Again ,I really appreciate all your input !!!!