Changed waterpump and themo not getting to temp

[HONDAKID11]

So i just got done with changing the waterpump, inlet and outlet tubes and the thermostat. Thats fine, but now the truck wont get passed 105 degrees.. I dove it down the road thinking there was an air bubble, drove 5 miles and it only reached 150 deg. And coolant is still full in radiator... I have a mechanical water temp guage thats replaced the sender on the block.

What could cause this to only read 150?? Guage is bran new

 

[tinman_72]

A mechanical probe is so long that it hits the exterior of the cylinder wall. I would not doubt it if you fried the probe.

 

[RonD]

Cold engine
Start engine and pop the hood
Feel upper rad hose, it will be cold
Run engine for 3 or 4 minutes
feel upper hose again, if it is warming up with the engine then thermostat is open or not seated correctly

Upper rad hose should not get warm unto coolant in engine is at 185-195degF and thermostat starts to open.
1995 2.3l engine will use a 192 or 195degF thermostat.

2.3l engines do not generate a lot of heat so will run very cold without proper thermostat.

There are two temp sensing units on all fuel injected engines.
ECT(engine coolant temp) sensor has 2 wires and is ONLY used by the computer
ECT sender has 1 wire and is ONLY used by the dash board temp gauge

Which one did you remove?

 

[Grey_04]

I have drilled a small hole in the thermostat ring to aid in the removal of air in the system that might be something to consider.

If you have one of those lazer pointers for temp readings you might want to check that against what your gauge is reading.

 

[HONDAKID11]

have 195 thermostat and i removed the one in the block with one wire.. i ran the truck for about 15 mins and didnt get any heat from the upper hose, after a short drive i had some heat in it, but it seems like the coolant is not flowing. possible the radiator is plugged?

 

[RonD]

The Radiator is there, on all cars/trucks, to get rid of "extra heat", while it is part of the cooling system it isn't a part that needs to be used, and mostly isn't in very cold weather.
Water pump circulates coolant thru the engine and heater core, it is a closed system.
When thermostat opens coolants path flows easier(less resistance) going out the upper hose and then coolant in lower rad is pulled into water pump easier.

If upper hose was heating up then coolant in engine must be above 180degF at least

What the temp of the heater in the cab?

What coolant ratio are you using?
50/50?

 

[HONDAKID11]

well the heat wasnt like burning hot, but it was warm. im going to flush the core and radiator today when i get home. but it is 50/50. one thing idk is the waterpump goes onto the block adn theres a huge hole for it rather than the water pump plate and smaller hole like other vehicles so it may just be that its having trouble circulating. my gf's cousin who is a ford tech said these trucks are normally a pain to get blead when you drain the coolant. ill know more when i can get to it today.

 

[mkyhmltn]

I found that the aftermarket thermostats dont seem to fit quite right letting to much coolant past them during warm up. I went to the factory one. Expensive, but helps.

 

[RonD]

Problem won't be air in the system, air prevents engine coolant circulation and if trapped at thermostat prevents it from opening at the correct temp.
So air will cause over heating, not under heating.

Always good to flush rad and heater core, but again these wouldn't cause under heating only over heating.

Fan clutch would be a stretch causing this issue but could if it was cold enough outside.
The fan is there to circulate air in engine bay and to pull air thru radiator once radiator gets warmed up.
Fan clutch is engaged and disengaged by radiator heat, when rad is cold clutch is disengaged so fan can spin almost freely, it doesn't pull or push much air, giving engine and engine bay a chance to heat up.
On the front of the fan clutch is a metal spring, as radiator heats up in the center that spring gets warmed up and expands, this movement starts to engage the fan blades to spin closer to engine RPMs, pulling and pushing air, this cools radiator when you are stopped or going slowly, the warmer the rad then more the clutch engages.

Cold engine
Start engine and run it for 30 to 60 seconds, this will set the fan clutch to outside temp
(You can also hear this happening on most cars/trucks, loud fan noise on cold start, then it gets less and less after 20 seconds or so)
shut engine off
pop the hood and spin the fan blade, it should spin easily, it will slow down quickly but should spin if you give it a good push or pull.
If it is tight, won't spin at all after letting go of the blades then that could be a problem.
Fan could be over cooling engine and engine bay, not letting engine warm up.

Fan clutch is suppose to "fail safe" in the engaged fully position if there is a problem, since more air circulation is better than less(over heating).


I had an old Dodge pickup with straight 6, I had to put insulation on the heater hoses to keep heat in the cab in cold weather.

 

[naford]

This might be wrong. Doesn't hot water come into the radiator from the top? If you take a temperature reading from the water at the top of the radiator that should give a fair idea of what's going on. You should be able to just let the truck idle and it will heat up. At least that is what happens when I move snow around I just leave the truck idling in the street. You could test the thermostat by boiling water and then drop it in. If you have a temperature probe you could then see that it should open up and then slowly close as the water gets cooler. I wonder if the thermostat is getting flexed when you installed it into an open position?

 

[kimcrwbr1]

How cold is it outside? Just a small leak past the thermostat will keep the engine cool especially if cold out. Many put a piece of cardboard in front of the radiator to bring the coolant up to normal temp.

 

[RonD]

How cold is it outside? Just a small leak past the thermostat will keep the engine cool especially if cold out. Many put a piece of cardboard in front of the radiator to bring the coolant up to normal temp.

And just as an FYI, covering the rad with cardboard or those zippered covers used on semi's is not for the rad, it is to slow air flow into engine bay.

Doesn't matter how much over cooling happens to/in the rad, thermostat would just close a bit more, or all the way, if rad was cooling the coolant too much.

Cooling down the engine and engine bay by air flowing in can't be compensated for by thermostat if engine can't reach operating temp.
So blocking that air flow can help in cold temps

 

[HONDAKID11]

Ok so here's an update..I flushed the radiator block and heater core. All had water free flowing. I bought a new thermostat, tested it it opened when it needed to, installed it and still not getting up to temp...I also replaced the heater control valve. So keep in mind I'm using an aftermarket mech guage. I drove down the road with the heater on got up to 160 on the guage. Turned the heater off and it went to about 180 just u Der 190 then it dropped to 170 and them did a little back and forth. So I think I'm ok, it just take driving to warm the engine up and the cheapish guage is off. I drive everything going is ok.. however my radio cap doesn't get hot... upper hose was hot after the drive.

I do remember the water pump has a fairly large outlet into the block.. that normal? Thought water pumps had plates on the back that only had like 1 in holes