running too cold?

[Litchkar]

Hello everyone,
I had my Challenger out for a drive today on a nice 70 degree day, Like always, the temp gauge reads on the low end of the non-rally gauge. When I got home, I checked it with an Infared thermometer, it read 170 degrees. I checked the rad, thermostat and upper and lower hoses. Even with the A/C on, it still does not get much higher on the gauge. Is this too cold for city driving?
340 stroker, 371 ci.
auto trans
26"
3 row aluminum radiator
factory fan and clutch
185 degree thermostat
17 LB rad cap

 

[moparleo]

Temp too low. Needs to be in the 190-200° range.

 

[Chryco Psycho]

is the engine warmer ? nice to have an efficient system !

 

[Litchkar]

is the engine warmer ? nice to have an efficient system !

I know most members have the opposite problem, so, what is the best solution to get it up? Engine block is cooler than that.

 

[Xcudame]

Buy an inexpensive temp gauge and plum it into the water pump/timing cover and leave it under the hood as it's temporary. Then drive it and see what it reads. 190° to 200°F like Moparleo said is ideal.

 

[Ricks72Chlgr440]

How long did you drive it for? Very strange that the temp was 170 when your thermostat is a 185. Wondering if the thermostat is really a 160? The best thermostat is one like a high flow Stewart Components. That unit has large windows for excellent flow and has a small hole to purge trapped air out.

 

[Ricks72Chlgr440]

In thinking about this, do you know for a fact that there is a thermostat in there?

 

[Litchkar]

In thinking about this, do you know for a fact that there is a thermostat in there?

I built the motor, it is a 180 thermostat, has always run on the cold side, been together a few years now.

 

[Chryco Psycho]

Thermostat could be stuck open

 

[Steve340]

As the engine heats and cools during operation the thermostat should open and close to keep the engine at the correct temperature.
Change the thermostat first job.

 

[Xcudame]

I think Chryco Psycho may be right, a stuck open thermostat. I'd put a 190°F thermostat in there like Rick suggested.

Another honky fix I've done in cold weather is block part of the radiator with a piece of cardboard. Sounds crazy, but it works and can easily be removed for warm winter!

 

[sixpactogo]

I'm not sure what your problem is but I can attest to having one vehicle with a similar problem. This was 30 years ago but my truck heater would provide heat at an idle but on the road it would not. I put the cardboard in front and it helped some but finally I ran into a guy that knew what was wrong. He told me my radiator was junk. I thought, how could that be since it never overheated? He showed me how easily the fins between the cores would bend. He informed me that the fins are there to help regulate the heat dissipation and without them the radiator would cool too easily. I got a new radiator and solved the problem at once. You could check yours by running a finger up or down between the cores. If they bend easily it could be your problem. How old is your radiator?

 

[Litchkar]

I went ahead and pulled the thermostat; it was marked as a 180 degree. When i put in hot water, it started to open at 180 and popped fully open at 185 degrees. I bought a 195-degree unit at Advance Auto, (in stock for 9.49). The gauge moved higher, and the Infared thermostat read 183 degrees on the top of the Rad. I know this is not the most accurate method, but as a reference to the other day, it was 13 degrees hotter than before. Happy with the results, and hopefully will pick up a little power.
Thanks to everyone who weighed in with their knowledge.

 

[Steve340]

You may not notice much or any power increase - but the cabin heater will work better!

 

[moparleo]

The factory thermostat was normally a 190-195°. Engines need a little heat to be efficient.

 

[Xcudame]

I watched my poor father (God rest his soul) soldier the same radiator multiple times (in different places) trying to fix it! I told myself then when in a similar situation with a bad radiator, bite the bullet, pay the money for a new one! Now we have aluminum radiators that look stock!