Car won't reach operting temp

[bobaganoosh]

I recectly put a 2.3 from a 89 in to an 88 vert. and the gas mileage is horrible ever since the temperature went down.

I have a feeling it's because the car won't reach operating temp. it takes more than ten minutes for the temp. guage to even move and when it does it doesnt' get higher than the first hash mark.

I changed the temp sending sensor cause the original didn't work at all, but haven't changed the thermostat yet

i used prestone 50/50 when I refilled the radiator and wonder if I should drain some out and replace with water so I can get a little more temp out of it.

what's your opinion

mike

 

[BlownFiveLiter]

The 50/50 mix should be fine, but you could probably go with something like 80/20 if you really wanted to. My gut instinct says it's the thermostat, but double check to make sure you don't have some air pockets in the system, too. Toss the front end on some jackstands so the radiator fill is the highest point, and burp the system. That could very well be the problem all along, and could save you from even having to change the thermostat.

 

[wv109323]

Car won't reach operating temp

Also check the radiator cap. If the cap is leaking, you will not build up the heat you need. With an open system the max temp you can reach is 212 degrees at sea level. Less at high altitudes. If you are adding small amounts of antifreeze like a pint a week suspect the cap.
Also make sure you have the right pressure rated cap. I believe a 16 psi is correct. If someone put a drastically lower rated cap that could be your problem.
The problem is probably the thermastat. The first one that I bought and I put in my car did not come with the correct rubber grommet needed to seal around the thermastat. I went back and the parts store sold me the wrong grommet. Buying a second thermastat with the correct grommet cured the problem. Also the original thermastat did not have enough of the rubber grommet left to discern how it sealed. The thermastat should have a round rubber grommet around the circumference that makes it fit snuggly back in the cavity for the thermastat.
I hope this helps. I don't want you to go thru the agony I did.

 

[RustBucket]

Also check the radiator cap. If the cap is leaking, you will not build up the heat you need. With an open system the max temp you can reach is 212 degrees at sea level. Less at high altitudes. If you are adding small amounts of antifreeze like a pint a week suspect the cap.
Also make sure you have the right pressure rated cap. I believe a 16 psi is correct. If someone put a drastically lower rated cap that could be your problem.

Huh? So if I heat water in a pot (an open system) I can only heat it to 212 deg. F? It'll start boiling at 212 without a doubt, but I can keep heating it beyond that. Now if I put it under pressure, I can raise the boiling point above 212 degrees. The higher the pressure, the higher the boiling point. This keeps the water in liquid form at higher temps so it will continue to do what I need it to do and that's pull heat away from my engine which is something steam won't do. On the flip side, the lower the pressure, the lower the boiling point. Water in a vacuum of 30" hg will boil and evaporate at room temperature. It's one of the reasons for pulling a vacuum on an A/C system before charging it. Any moisture trapped in the system evaporates. But anyway...

Typically if a car has a bad radiator cap or some other reason for loss of pressure, it overheats. It can't maintain the pressure it needs to raise the boiling point and keep the water "wet".

When someone says it's not building heat, it's either a bad or missing thermostat, bad or inaccurate temp gauge, or a bad temp gauge sending unit.

 

[bonestock87]

Simple one, it's the thermostat.

 

[blue71mustang]

Hopefully simple.

I changed the sender and thermostat and I still only reach 140-145 at best on the gauges, but you can just about melt your shoes with the heater blowing on full on the floor. My fuel mileage did increase by 4mpg by changing the sensor. I'm at a loss to explain my gauge reading.

If you aren't getting heat or very low heat on your car, I'd suspect bad thermostat. My previous thermostat would also stick periodically giving me an over heat situation at low speeds.

 

[bobaganoosh]

haha

crap I didn't even think about the thermostat missing, the motor in this car came out of a parts car that I bought off this kid, and the parts car was hacked to pieces when I got it (it was running) but the thermostat didn't work and the fan was hardwired to the starter sylenoid so it was always on when the car was on, I replaced the temp sender and the temp guage works fine but never thought they would take the thermostat out to keep it running cool.

also I found a new problem with the a/c knobs no matter which setting I put the control knob on the air only blows out the defrost vent, anyone ever have this problem

mike

 

[rd]

Yep, check out the vacuum to the heater/ac controls. Make sure the hoses are connected, and there is vacuum available.

If that does not fix it, start checking the vacuum motors to the doors that direct air to different places.