Awhile back I put in a 180 TSTAT. I notice that when in slow city traffic or at idle the temp will still get up over 200 degrees but when cruising on the highway the TSTAT regulates it and keeps it down. This morning it was hovering around the mid 170 degree range and I got the P0128 temp code prompting me to ask this question. I hear that most if not all people change their fan settings via the Predator. I would like some detail on why this is and what affect it has. I should add that as I understand it, adjusting the fan temps would help keep the temp closer to whatever I set the temps at via the Predator during city driving and won't affect my current highway driving situation. Thanks guys!
That would be correct. 1) A t-stat sets the *minimum* temperature your engine runs at (once it warms up and if you're not in the artic circle at -50). 2) Air flow over the radiator determines the *maximum* temperature your engine runs at. Up to some point... assuming the cooling system has the capacity and the coolant is moving fast enough, yada, yada. Our engine cooling system has PLENTY of capacity so it's a matter of air flow. (Naturally, if the t-stat is closed and coolant is not circulating, you can't flow enough air over the block to cool it below the t-stat temp) The fan turn ON temperature stock is about 209 for the low speed fans and about 220 for the high speed fans. Note: the turn OFF temperature is about 3 to 4 degrees below the turn ON temperature. Fans kick on, temp goes down 3 to 4 degrees below the turn on temp and the fans kick off. Note: there are a number of things that will trip a temperature fault. Usually they are the kind of faults where it has to happen a number of times over a number of key cycles. Like if the temp doesn't get up somewhere between 167 and 177 withing 10 minutes of running after starting the car and that happens 3 times in a row. That kind of thing. If you have a 180 t-stat then you should NOT be seeing it hover around 170. The car should warm up fairly quickly to 180 or just above and never go below that after warmup. You may have a sticky t-stat or you may not have installed it so well. I would buy another one just to be sure. Before you put the new one in get a cheap meat thermometer and put it with the t-stat into a pot of water on the stove. You will be able to watch it open and close and what temperature it does it at. (If you test the one you have now antifreeze is not good to eat. Wash the pot after). It's usually the guys who use 170* or 175* t-stats that see the code for that. So... you want to set your fan turn on temps with the predator to take advantage of your lower t-stat. You're probably not going to want the fans running all the time. You can just hear the low speed fan and the high speed fan is downright noisey. Set the low speed fan at least 4 to 5 degrees above the t-stat open temp. I'd set the high speed fan 5 to 10 degrees above the low speed fan. (we don't have mid speed fans so it doesn't matter where you set that). You cannot screw up with the fan settings unless you set them up over 250 or something. Worst case is they run all the time. I have the motorad/valu-craft t-stat which is actually 185*. I have my low speed fans set to 192 and my high speed fans set to 199. The Jet t-stats are 180*
Here's a link to the How-To for fan settings... http://www.srtconnection.com/forums/showthread.php?t=7403
Well that clarified things a bit, thank you! I've had the TSTAT in since last summer and this is the first code I've thrown. When I get a chance I can pull the TSAT and re-install. If that doesn't fix it then I'll consider buying another. I thought mine was a Motorad but not positive now. I thought I read before there was some type of marking on the TSTAT that identified it?? Wish I had a spare plastic bag handy, I'd pull it on break.
Pretty much the two that are available are the Motorad (also branded as Valu Craft and something else) and the Jet. The part number for the motorad is 4128? and I think the 170 or 176 motorad is 4127? AutoZone sell them branded as Valu-craft. Yes it has motorad or something stamped on it (inside one of the spokes I think). I think Jet comes with a gasket and motorad doesn't? You need to save your gasket. The motorad fits TIGHT. I took mine and turned it with a drill against a file to take off about 1/16" diameter. most people don't bother.
Yep, sounds like I have the Motorad then. Sounds too familiar. So then that's even worse that mine actually a 185 TSTAT and I was reading 170's. I'll have to watch more carefully on the way home today. Outside temp is maybe 50 and raining, wouldn't matter right?
Rain will just cool better. No matter what, it should not drop below the t-stat temp once it has warmed up. If you're on the freeway in that kind of weather it should run within 1 degree of the t-stat temp. We were all smarter back then
This is the second year for my 180 stat. I think you are lucky on not throwing the p0128 code considering where you live. I'm in Penna. and will trow the code regularly whenever the air temp gets below 50. It is a PITA. I drive around with a scan tool in the car so I can reset it. Have tried 3 different stats, used the Ron recomended fan temp settings and run the Predator 91 octain tune. Have tried any recomendations to prevent it, but nothing works. But the car sill stay below 190 even in summer with the a/c on.
Hmm, that is odd. I've read most people don't have issues with the 180. I think we need more details about what actually triggers the code. I watched my temp all the way home last Saturday and it was either 179 or 181 during the whole highway trip which is about 25 miles. Temp bumped up to 183 when I cruised in 4th gear the last mile or so. No codes thrown. Have you watched your temps in cooler weather?
I had my 180 thermostat on all winter here (first year with it) in Jersey and never saw anything... It was below freezing plenty of times, and while it took longer to get to the 185 range - it got there just like it does most any time. And no codes. Even if it was in the single digits out, the initial temperature would be higher, perhaps in the 30s... I'd warmer it up until at least 100 before driving... and 10 minutes or so later it would be over 180. I have my fans set for something like 189 low, 194 mid (I think these are useless - right?), and 199 high. Never gets over 200 any time, and 98% of the time I'd say it is under 190.
No matter what temp stat. you have, it's always a good idea to allow your vehicle to come up to about 100 degrees ECT before operating. If you do this, you will never throw a P0128 & CEL...I've practiced this since 07 with success.
So... it's the "integrated over time" thing that's probably tripping the fault with the lower t-stats. If it doesn't get up to the expected temperature in the expected amount of time then it trips the fault. I think that expected temperature is something within the range of 167* and 176* or 17something. within some amount of time... like 10 minutes? Note that they factor in ambient temperature, and how the vehicle is driven following startup. The algorithm might vary the time and the target temp before making the comparison. For basically stock engines the thing is this. The t-stat goes from full closed to full open in a fairly small range of temperature. As long as the t-stat doesn't open before that threshold the PCM is looking for it shouldn't make any difference. Let's say the PCM is looking for 175* after 10 minutes of normal operation. Let's say your 180* t-stat starts to open at 177* and is fully open at 180*. Let's say the stock t-stat starts to open at 200* and is fully open at 203*. Both t-stats are FULLY CLOSED at 175* so it shouldn't make any difference for the fault. You might expect those guys with the 170* and 176* t-stats to maybe throw codes. Not the 180* t-stats and certainly not the 185* t-stats. If you do, I'd first pull the t-stat and check it with a thermometer in a pot of water to see if it's calibrated. Then I would look for sticking. Then I would look at installation. For modified engines and/or cooling systems Of course, if you've significantly modded your engine and or your cooling system then it's not going to warm up like the model that's programmed in the PCM which models the stock engine and cooling system. Kyle, yours probably stays closer to the model if you let it warm up idling and farther away from the model warming it up while driving. Others might not.
The Motorad Tstat will not come with a gasket and it is very hard to get in and out wihtout damaging the gasket. Somewhere I posted the part number for the gasket and most aurto parts store have the gasket. I believe the Jet Tstat fits easier.
Yes the Jet fits a bit easier (and I think it might come with a gasket?). The Jet is a 180* The Motorad is a 185* No reason, but I think the Motorad is made a bit better. You can take the Motorad and carefully (gently) chuck it in a variable speed drill. Turn it slowly against a fine metal file and take a mm or two off the diameter and it fits perfectly
