Thermostat choice

[Hobbyranch]

My truck is running warm and I want to replace the thermostat. Rock auto has temp ranges available from 160 to 190, seems like the 160 would be a logical choice to cool it down but I’m not sure if that would be too low. Any suggestions? Thanks!

[geezer101]

I personally wouldn't go that low. I'd use a 170 if I was going to try and keep engine temps down. First thing I'd try is to do is reduce engine temps by improving cooling system efficiency. Maybe the thermostat is getting jammed or your radiator is clogged up? They make high flow thermostats now so that could be an option...

[SubGothius]

Yeah, figure out why it's running hot. 180-195°F is the correct T-stat spec, and swapping to a cooler one is just a band-aid on the symptom that will only make your engine take longer than it should to warm up fully, which will tank your fuel economy. Once the T-stat is open, regardless of its opening temp, the coolant temp should wind up reading about the middle of the gauge -- even here in Tucson where the highs flirt with 120°F in midsummer.

I'd start with a thorough cooling system flush, and not just with water; use a radiator flush-cleaner product to dissolve scale and rust, and follow the directions for the most thorough method they recommend. At least in summer you won't have to worry about it freezing, so you can safely leave it in there a few days.

[xboxrox]

X3 on flushing the cooling system & use new coolant ~ ignition timing greatly affects how hot the engine runs ~ check the timing if too far advanced the engine could overheat ~ personally I would stick with original spec parts ~ enjoy the fixings

[Hobbyranch]

Thank you all!

[xboxrox]

Thank you all!

REPLACE THE RADIATOR CAP <---- DO THIS FIRST ----> AN OLD CAP MIGHT NOT BE HOLDING TH 15PSI COOLING SYSTEM PRESSURE ----> NOT ENUFF PRESSURE EQUALS OVERHEATING OR RUNNING HOTTER THAN NORMAL

[BROG]

Run some thermocure in the cooling system with some distilled water for a week. I've used it several times in my Land Cruiser builds, the stuff will clean your cooling system amazingly well, it's way better than any acidic flush you can buy.

[tortron]

Soda crystals are great for cleaning out a cooling system. Get them in your supermarket cleaning Isle

[d50Lewis]

A copper core radiator transfers heat 35% better than an aluminum radiator. I had a 3 row recore years ago and it stays cool even hauling my Jetskiis to the Colorado river across the socal desert running the A/C.

[Hobbyranch]

Thank you!

[dash]

A copper core radiator transfers heat 35% better than an aluminum radiator. I had a 3 row recore years ago and it stays cool even hauling my Jetskiis to the Colorado river across the socal desert running the A/C.

if copper transfered heat 80% better than aluminum, makes no difference. Aluminium radiators get the job done
500hp street honda civics do fine with their "half-sized" aluminium radiator. Find the overheating culprit

[geezer101]

+1 on the overheating issue. Check the face of the radiator for cold spots as it should give you an indication of poor coolant flow. I haven't used soda crystals as recommended by tortron but I have filled radiators and heater cores with citric acid solution to de-scale them. Worked very well - I would also heat the core tubes with a heat gun to excite the solution and flush the stuff through the radiator as best as possible before flushing both directions with a garden hose thoroughly (leave the solution in for 1/2-1 hour. Radiator out, lying face down on a flat surface with the cap on, drain, check and repeat as you feel necessary) Straighten any bent fins, strip the radiator with paint stripper and paint it with satin epoxy black paint. It will be as close to new as you will get. The mechanical fan lets the cooling system down and these trucks are prone to heat soak, so any improvement you can make to heat dissipation will help preserve the head.