85 running Hot or Cold?

[YungICY]

Hey guys I have a bit of a brain teaser that I need some input on. I can't tell if my engine is running hot or cold.

First things first I'll give you a breakdown of the truck.

It's a mildly built 2.3. Shaved head, big cam, holley 350 cfm carb, esslinger underdrive power pulley and water pump pulley (stock water pump & 192 stat).

I have aftermarket gauges on the inside (equuis). The temp gauge uses some kind of pressurized tube that runs to a probe that I have in the stock location on the block.

Here's where things get interesting. The stat is definitely opening because the upper hose gets plenty hot. The radiator (stock) will get warm after a while and the lower hose will get warm after a while but cool enough to grab. The temp gauge tells me I'm running at like 170 degrees.

I can only logically think that as the cooled coolant goes back into the engine it is only hitting 170 as it passes by the temp probe and 192 or higher by the time it gets to the stat but that seems somewhat unlikely. Or that the gauge could just be out of calibration.

Also one other tidbit is that the carb is running a little rich.

And anyone shed some light on this?

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[RonD]

Temp reading will depend on where the sender is located.

192 t-stat will start opening at around 190degf

Radiator usually cools coolant down 15-20degf, 15deg idling, 20+ deg driving, better air flow

If temp sender is near t-stat housing, most are, then it should be reading closer to 190

If it is nearer lower hose, cooled by rad, then it will read lower.

best thing would be to read temps using infrared handheld device, at the sender and upper and lower hoses

Rich running, is choke plate opening all the way, it needs to be adjusted twice a year, for winter and summer temp changes.

 

[YungICY]

Sender probe is located at the back of the block just below the oil pressure port. What type of temps would I like to see with an infrared scanner? Choke is open all the way it just needs a lil smaller jets.

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[RonD]

infrared thermometer would show you thermostat housing temp, with upper hose warmed up it should be 185-195

Then lower rad hose connection on engine end should show about 15-20 deg cooler

Turn engine off for the testing

Odd spot for a temp sender, on the block, cooler part of the engine, the head is where all the heat is generated.
So the 170 reading is probably correct

You may want to just plug that hole and use a bung on a heater hose and put your temp sender there, better place to get instant overheating warning.

You can look here: http://www.autometer.com/accessories/adapters-fitting-hose.html

7th row down are the bungs for smaller hoses.
You want it on the "out to heater" hose of course, as close to the engine/water pump as practical.
These only work well if heater hoses have constant flow, many earlier Rangers have coolant flowing through the heater core all the time, or have a by-pass valve that cuts heater core flow but keeps coolant flowing between heater hose OUT and IN on the engine end.

 

[YungICY]

So to moniter coolant temp you ideally would pay attention to temp as it exits the engine. Makes sense. I never thought about putting a bung in the hoses. That would work very well on my heater hose since it has constant flow.

Thanks Ron.

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[RonD]

Your welcome.

I never knew the 2.3l had the temp sender there.
Yes you will certainly get a better temp setup the higher you are on the engine cooling system, best to monitor max. temp than return temp, also better in case air gets in the system, it always goes to the high areas and will cause a temp sender at that location to fluctuate the gauge.

 

[tomw]

All 2.3 temp gauges have had the sensor in the block above the oil filter. The water jacket around the cylinders likely doesn't have the highest temperature coolant, which I expect would be around the exhaust port in the cylinder head.
If you are concerned about temperature, use a non-contact thermometer to measure the outlet temperature immediately after the thermostat housing. The stat will open and close depending on temperature, and will try to regulate the temperature near the rating.
I had thought 195F was the normal temperature thermostat to use in the Lima. If so, you'll get better running with the higher temperature stat, and better fuel economy.
I believe there is another temperature sending unit that the computer uses to help determine open/closed loop, timing and fuel/air mix, along with cold idle speed. It is not on the side of the block near the filter. If you have a carb setup, I don't think it is installed or used unless the carb has 'electronic' controls.
tom

 

[YungICY]

Yeah 195 might be right. the 192 is just what I remembered off the top of my head. Either way, I believe it was the hottest OE replacement. Now that you mention the other sending unit it would make sense that the one in the block isn't in the best spot. The one in the block originally went to my dummy light on the dash and it's possible that the sending unit for that was calibrated a little cooler. The one that went to the EEC I still have in just to plug the port. The coolant T's off the heater hose and comes into the bottom of the EFI intake and the sending unit is right in the middle of the top of the lower intake.