Recently bought a used 1993 ranger 2.3L manual with 100k or 200k. Fixed a few things on it like, transmission was stuck in 3rd gear, replaced 4 of the 8 wires/plugs on the left side.
replacing the other 4 on the right side soon.
my issue is: the engine won’t get to normal operating temp and I have read a lot of other posts on this.
the temp stays to the left of the normal bracket.

some background as to what I’ve done:
I replaced the thermostat(verified it works 195 degree) before install.
flushed everything, radiator, hoses, water pump and heater core.
also have the fan removed from the system, viscous clutch is still there to hold pulley on.

without the “fan”, I can get inside “normal” only after it’s been idleing for 10 min, but still no heat.
i do get the radiator hoses nicely hot and get 195 degrees with my infared pointing at the thermostat and still no heat.
thinking I have a faulty fan clutch, can’t find much online to test them. I tried to rotate it (cold) and it rotated 1/4 turn. Heated it up and watched the spring tighten, rotated maybe 1/2 turn. So thinking that’s faulty.
the temp slider on the dash has a cable and not sure where that goes or what exactly it controls.

wondering my next course of action without throwing parts at it,
sorry about the longness, just want to give as much info as I can.

 

Have you checked the heater hoses? Might be issues with the heater core or something. I dont know, mine gets toasty after about 10-15 min run time.

 

Checked all hoses when I had thermostat and water pump out.
flushed everything with the water hose.
heater core had some gunk in it but was not blocked.radiator has sludge in it, wouldn’t drain till I shot it with 40psi.
All hoses are clear and fresh 50/50 is in the system.
still nothing

 

Welcome to FTE.

You've been busy on this puppy & seeing as how it's OBD-1 diagnostics, you might find this archived site http://web.archive.org/web/201308190...ction.com/?p=1 with all kinds of early Ranger sensor values & reading helpful, here is some good info from it in checking out the temp sensor values Fuel Injection Technical Library » Engine Coolant Temperature Sensor (ECT). We have Two coolant temp sensors, a single wire one for the dash temp gauge & a seperate Two wire one for the engine computer. SO, which coolant temp sensor was replaced???

From your IR measurement feedback, it sounds like the thermostat is working ok as the hoses are hot & the IR sensor says its in the right range. SO, if the dash temp gauge is still indicating the engine is cold, suspect the single wire coolant temp sensor, its wiring, electrical connector, or wiring run to the gauge. A quick check of the gauge & wiring run can be made by turning the ignition switch to On, grounding the Temp Gauge single wire sensor electrical connector & see if the engine Temp gauge goes to full scale hot. If it does, the gauge & wiring are ok, so suspect the gauge temp sensor & measure its resistance with your multimeter.
NOTE: be careful what you use for a sensor thread sealant, PTFE ribbon dope isn't recommended as it can insulate the threads & cause a poor or no ground connection to the engine & muck up the sensor output to the ECM or temp gauge. Use something like Loctite 565 https://tdsna.henkel.com/americas/na/adhesives/hnauttds.nsf/web/2675723BB7F1421C882571870000D819/$File/565-EN.pdf.

On the no cabin heat, are Both heater hoses at the firewall getting hot???? If not, you have a flow problem through the in cabin heater coil. So did it get back flushed separately when you were servicing the cooling system??? If it was flowing flush water ok, then you have some kind of water, or air flow Control problem. So if Both heater hoses are getting hot at the firewall, suspect a in cabin air blend door problem.
More beginning trouble shooting thoughts for consideration, let us know what you find, can't have you driving around cold this winter!!!!

 

Pawpaw, appreciate the assistance.
i did not replace any coolant sensor. The engine computer sensor was tested and works IAW with the link and resistance/temp changes.
the dash sensor works but the engine takes a long time to get to the O in normal. When it gets to the “O” I am reading 195 IR at the thermo, 180 top of the radiator, 120/85 at the heater core hoses... with the dash sen
with the above, I am now getting more heat in the cab than before, now I’m getting 75 degrees. Only thing I did extra was to touch the blend door.
all this was still done without the fan on the clutch and it is currently 50 degrees here.

Coolant sensor for the dash seems to be good, since it is registering. Is this all it feeds?

imo, the items suspect are;
1. Blend door
2. Water pump may be low flow? Not sure how to verify that or would low flow cause this issue?
3. Viscous fan clutch, from previous testing.

with the blend door next, does that involve removing the dash?
thoughts?

 

The temp gauges in these things generally don't go above the N in NORMAL, but you have hot rad hoses so everything inside the engine is working as designed, it's likely the temp sender for the dash gauge is old and tired or new with too much thread sealer on it. The. dash sensor is not the one in the thermostat housing, it's buried down on the side of the motor IIRC

And another note, if you live in a northern climate the truck will need a winter rad cover if you do any highway driving.

No heat in the cab is a separate problem. Check the heater core hoses for heat, if only one of these is hot the heater core is plugged. Sometimes they can be flushed with a garden hose other times they have to be replaced.

 

not so concerned anymore with the temp dash reading.
heater core like all the other hoses and radiator have been flushed and are getting hot.
i did cut a hole behind the glove box and was able to observe the blend door doing what it should.

About to take the guess work out of the equation.
ordering a new water pump and viscous fan clutch.

 

Got my water pump and viscous Fan clutch today, installing water pump shortly.

i was expecting the fan clutch to be free spinning, but it’s same as the old fan clutch.
is there some test to verify the viscous fan clutch is working properly?
the old one, I took a heat gun to it and saw no change in the “catching” of it.

 

The fan clutch turns free, with some resistance cold & locks up with more resistance to turn free as the under hood temp rises. The fan clutches don't fail often, only when they leak fluid, or a blade cracks or breaks.

Now with all of the deposits you had to flush out of the radiator, you may find the heater core tubing walls are covered with deposits & aren't conducting heat as well as they could.
If your having engine over temp problems at highway speeds, or say climbing a long grade under load, then with all the cooling system debris you said you flushed out might also have water pump impeller erosion, or block deposits that are insulating heat flow into the coolant. If its a water pump impeller erosion problem, a new pump would be in order. If its a deposit problem in the block, head, heater core & radiator, then time for a heating system cleaning agent to be added, run as specified, then another cooling system flush until the flush water runs without color or deposits. Then drain & fill with distilled water to remove, or dilute any remaining tap flush water, drain that & add uncut coolant amount = to a 50/50 mix ratio of the cooling system total capacity & see how it goes.

If the cooling system & heater core temp are ok, but the heater output air temp is still wimpy, have another look at the blend door operation, as its a common problem on no, or wimpy heat woes.

 

Got the water pump and fan clutch installed.
getting some decent heat with dash temp gauge at the “N’ in normal.
will test more on the heat with regards to staying warm.

seem to have another issue now and I’m sure it’s related.
seems to be a squeaky belt tensioner and after looking at the belt path.
i should be able to remove the belt and make sure it’s not a new squeaky water pump.

 

Ok good feedback on things looking better for cabin Heat.
On the squeak, the idler pulley is a good suspect too, so remove the belt & check the idler & tensioner pulleys for rough feel, or looseness / side to side bearing wobble. The bearings should be smooth & snug when rotating, no free-wheeling & no side to side looseness / wobble play & no rough feel when rotated.

 

Update,
found the bolts slightly loose on the fan pulley, guess I didn’t tighten them fully.
sprayed water on the grooves and squeezing stopped till the water dried, so I know it’s not a bearing from alt, ps, ac...
there was very little play on idler, no play on other pulleys
there is groove on the outside edge of the belt which appears to be caused by tensioner pulley, in addition to rubber in all the pulleys.
I have ordered a tensioner assay and a new belt and in the meantime, will clean the grooves in the pulleys.

 

Stick a straight edge across all the pulleys to see if they are aligned, sometimes on these older motors a shim is needed here or there to make everything line up. It's also possible some of the parts in the system aren't correct, at this age who knows what has been replaced by a PO.

 

Ok, good finds & feedback & good idea to clean all of the pulleys. If you've found some play in the idler I'd replace that puppy too, along with the belt, while your in there. Where did the belt tensioner gauge register on its tightness scale???

 

^+1 on using a straight edge to check pully alignment!!!!