How hot does your PA run?

[Smith1000]

I have a 2002 that runs about 200-203 degrees. I noticed today on the interstate that when cruising, it was about 207 degrees. It seems a little hot. Is this the normal temperature range? The thermostat reads about 1/2 on the gauge or slightly over. I was curious what everyone else experiences.

[C man]

Before I changed my radiator my temps would run around 195-205 degrees in city traffic. Highway traffic it would run at 192-195 degree more so at 192 with consistent cruising. I used a scan tool and from personal observation the temp gauge would be one mark lower on the interstate. With my new radiator which is about twice as thick as the old one city temps run from 188-196 but mostly at the 194-196 mark since the thermostat is rated for 195 degrees and daily temps have been at the bordline 100 degree mark for the last week. Highway cruising temp has remained the same at around 192 degrees. These cars have good coolant capicity. For my normal driving conditions (city) with my new heavy duty radiator the temp gauge now reads on mark lower.

[Smith1000]

Interesting. My old Lesabres used to run similar to what you are talking about temperaturewise. They also had larger/thicker radiators. This '02 PA has a fairly thin radiator. Today, cruising home, it was running about 208 degrees on the interstate. One thing about it though, it gets good mileage--much better than my old Lesabres. Cruising at about 79 MPH, it average 29.3 MPG. The AC was on and I drove 90 miles. If I reduced to 74 MPH, it would do about 30-31 MPG. I wonder if the higher operating temperature improves the gas mileage?--probably not. What kind of mileage are you getting? The temp gauge reads "normal"; however, I do not know how accurate the electronic temp reading really is (either)

[C man]

I do mostly short trips now. I use to average around 19-21mpg when I had to travel farther. Now my usually average is around 18.5mpg. But for the past month it has been in the 16-17mpg range. I going to change my spark plugs wires tomorrow because the gas mileage drop happen all of a sudden even before I put the new radiator in. They're duralast and have been on there for almost 59k miles. On a highway trip doing anywhere from 80-95mph I got 24mpg and I have gotten as high as 33mpg driving reasonably. But higher temps do equal better combustion. Once I change the spark plugs wires I can see if the dropped temps have any connection. I doubt it though since there only a 10-15 degree difference in the idle tempeture in traffic with the new heavy duty radiator.

[HotZ28]

Engine temps should run within a few degrees of the thermostat rated temp while driving on the highway, provided you have a good coolant mix (50/50), with unrestricted flow and good heat transfer through the radiator. Due to some modifications (14.5 psi boost and other things) I run a cooler thermostat (160 deg) in the spring/summer & (180 deg) in the fall/winter. Last week, we had 97 deg ambient temp & while driving at 70 mph on the highway with a 160 deg stat, my engine temp was reading 162 deg on the scanner, as well as on the gage. I would suggest using at least a 180 deg stat in the summer. Cooler engine temps have no negative effect on the gas mileage. Anytime your engine is in closed loop (140 deg+) and the 02 sensor is functioning properly, it will do it's best to maintain a 14.7 AFR.

[C man]

If you run a 180 degree stat will your trans temp be around the same temp? I know the usually run around the same temp but the trans temp take longer to get to the same temp as the coolant. My trans was running at 195 degrees with the ambeint temp being 95 degrees yesterday. Coolant was at 191 degrees. I do mostly short trips and usually the trans temp only gets 150-170 degrees by the time I make it to my destination.

[HotZ28]

There are many variables which have an effect trans fluid temp. i.e. ambient temp, number of shifts, TC lockup, external coolers, air flow, & heat transfer, just to name a few. Normal driving at highway speeds in 4th gear (TC lockup) without an external cooler, the trans temp should remain within +5 to 10 deg of coolant temp. Of course, stop & go traffic with constant shifting, can raise temps much higher. C man, check your PM for more info.

[Smith1000]

I watched the temperature gauge closely today on my way to work. The outside air temp this morning was 69. I go about 30 miles to work. The temp slowly continued to climb during the first 15 or 16 miles of the trip and finally leveled off at 199 degrees. I did notice that, when on the highway cruising, when the temp was about 179, the MPG was reading 30-31 MPG with the cruise on. For the return trip, it reached 205 on the highway and it did not not climb any higher, even at idle when stopped. I believe the thermostat it calls for is a 195 degrees, so it is running a little hotter. I will blow out the radiator with air and water this evening to ensure it is getting good air flow. If this doesn't help, I'll change out the thermostat.

[Smith1000]

I cleaned out the radiator fins and changed out the thermostat to another 195 degree thermostat. It has been running about 202, but did get up to 205 yesterday, so this did not help much. I picked up a 185 degree thermostat yesterday. I could not find a 190. I'll install it this morning. It takes about 10 minutes to change out the thermostat. I am getting ready for a trip, which will involve mountain driving, so I would rather it does not go over about 200 degrees. I checked the anti freeze and it says it is good to -40.

[Smith1000]

Okay, I changed the oil and switched out the thermostat. What they told me is a 185 degree thermostat is stamped 180 on the bottom. At any rate, it is running 183-185, which is fine. It will probably go as high as 190 when it is very hot out.

I set the cruise on 60 mph and the temp reads 183 degrees. The oil pressure reads 63 psi and the fuel economy reads 31 to 32 mph, depending on the grade, but it was mostly flat.

[HotZ28]

I think you are ready for your trip to the mountains. Have fun and enjoy the trip!

[Smith1000]

Thanks! Also, thanks to you (C man too) for the great advice!

[Smith1000]

It ran great and the overall average gas mileage was 27.4 mpg over 2,000 miles. It ran about 185 degrees when cruising, but climbed to 226 degrees before reaching the summit of Wolf Creek Pass. We turned on the heat and opened the windows. This dropped the temp to 216, all of the time reading "normal". On the downhill side of the mountains, it ran 178 degrees. The guy in front of us smoked his brakes on the downhill grade.