Thermostats

[afsigma21]

Anyone ever installed a lower temp thermostat? I ordered, but have not installed, a 180* thermostat.

I am pretty sure mine is currently not opening at the right temp, so I want to put in a new one.

In my 02 Dakota the 180* thermo was a noticed change when under heavy loads. I am just curious if anyone did this, I have not seen it mentioned.

[Rebel]

Changing to a lower thermostate and the difference you see will vary. In other words, it depends on how marginal a system may be. It could do exactly what you want. Open at 180*water goes in rad. to cool, water in block heats up to 180* and open again. I have a marginal cooling system which is a V-8 and 3 row rad. with duel electric fans and after I installed a 180*, it opened and closed a couple of times in city driving, both the temp in rad. and block would both go over 180* keeping stat. open and coolant would over heat, never getting a chance to stay in rad. long enough.
Never know until you try it out.

[CaptSquid]

I'd install an auxiliary electric radiator fan instead. There's a reason the engineers installed a 195º t-stat in the first place.

[afsigma21]

I put the 180 in on Friday and had a short weekend trip planned, so I rolled the dice.

I put about 200 miles on it immediatly after changing.

I am not sure what the exact temp was it ran at, but it was much lower than previosly, but I am 95% sure I had a bad Tstat in it prior to the change.

If the guage looks like this:

100 . . . | . . . 210 . . | . 260

With the old Tstat in it would settle in at close, but just below 210 consistantly.

With the new 180 Tstat it ran steady at the bolded hard dash between 100 and 210. I dont have a mechanical guage yet, but will eventually so I dont know the number exactly.

Here are the relevant facts:

Drove straight shot 80-85 miles mixed highway and city. 50 hwy then 15 city then country roads varying speeds to destination.
high 70's outside temp
Fuel economy seemed increased, more miles needed to confirm.
A/C worked with no isses the whole time
Drove around local for a day
Drove home the same 80-85 miles.

Temp stayed steady.

I assume I will suffer from the lower temperature when winter comes around with less effective heating.

I know I need more miles for better info, but this is what I am reporting so far.

The only real question is, Is there a problem running the engine at a lower temp?

[Smiliesafari]

No problem at all. In the not to distant past all vehicles came with 180 degree thermostats.

[afsigma21]

Changing to a lower thermostate and the difference you see will vary. In other words, it depends on how marginal a system may be. It could do exactly what you want. Open at 180*water goes in rad. to cool, water in block heats up to 180* and open again. I have a marginal cooling system which is a V-8 and 3 row rad. with duel electric fans and after I installed a 180*, it opened and closed a couple of times in city driving, both the temp in rad. and block would both go over 180* keeping stat. open and coolant would over heat, never getting a chance to stay in rad. long enough.
Never know until you try it out.

I wanted to revisit this now that I have had some miles on the lower temp Thermostat, and make sure I understand what your saying.

With the 180 in, and normal city driving with a couple passengers, and no extra load (Other than all the extra stuff because its a high top conversion) I run really really cool. I like it there, it makes me believe that the trans is cooler too... maybe not.

So, last weekend I loaded up the van with 4 boxes of ceramic tiles, 3 cases of bottled water, misc camping gear and 5 adults including me. Hooked up my Jetskis (1500lbs) and hit the road for a test tow. AC on the whole way, 85 outside temp.

I towed in 3 and in about 20 miles I was already closing in on 210. Got off highway and drove thru a large parking lot, stopping, starting over and over to simulate a traffic jam. Temp was steady at 210. Got back on highway and in D was at 210, in 3 it lowered a bit but not much, still, below 210. 20 miles later got off highway and at stopsign on ramp hit 210, got gas, went 2 miles home and was just under 210 then.

A few questions.

1. Running at 210 for extended periods OK, what about over 210? How high is acceptable?

2. It sounds liek my thermo is staying open, so the coolant is at a constant flow and doesnt cool off before going back in? Sound right.

3. If I go to a 195 again, could I actually tow cooler, will it hold teh coolant in radiator longer?

I am bone stock except the second largest LPD Trans cooler I could find. 9 x 12 I think, but skinny, not thick. Mounted away from the condenser.

If I want to tow my boat at 3500 lbs I am scared.

What options do I have?

[Smiliesafari]

A steady 210 is no problem. If the needle starts toward 250 you have a problem. I don't think towing the boat is a problem either. I towed a '97 Astro conversion (4000 lbs.)with a very large trailer (1000 lbs.) and had no problems. Something you might want to check is a partially plugged radiator if the temps rise slowly to the dangerous side.

[e7ats]

Your rad fan kicks in at about 200-210. Even though your Tstat is open your coolant won't drop till the fan starts pulling the air across the radiator. Even going down the road the fan will kick on to help cool it down.

Personally I like running the 195 Tstats my self. 1 it helps burn the fuel cleaner (less carbon build up). 2 You will notice a big difference in the winter. As long as the T stat stays closed it will send hot coolant through the heater core, but when it opens up that water will stop flowing and it chills off very quickly.