So, this constant P0128 code my car throws now that the weather is cold is getting old; I keep the scan tool in the car so I can reset when I pull over which is happening everyother day. I've been driving around with the additional displays up so I can monitor the actual coolant temperature - it runs a constant 176 degrees. Car has a JET 180 stat that went over 10,000 miles in warmer weather without codes. So I guess running at 176 it is just on the low end of the specs. I figure that if I get a slightly warmer stat, I should be able to avoid the P0128 in the cold weather. Following leads here, I check the Auto Zone web site, find the Motorad 4128 listed as part 15128 and in stock. Go to the store, where after some searching the guy finds it listed in inventory as part 4128 (eventhough the box also has 15128 on it). I buy it, $14.88 + tax, they don't have a gasket availible, not even listed. Opening the box, the stat is stamped Motorad 4128 Germany and the actuator is stamped 180 degrees, not 185. now what?? I guess I'll try it in a pot of water on the stove and measure where it actually opens, hoping it is higher than the one I have now. Is there a real 185 or 190 degree stat out there? I'm so confused, my head hurts.:search:
Just adjust your fan setting to a higher temp. with the predator. I use 179 for LS and 190 for HS and never a code with Jet 180. Car runs at 180 and max temp it ever sees when flogging on it is 190.
Thanks for your input, but my fan settings are higher than that. It is cold enough here (14 this morning) that the fans are not coming on, there is enough cold air flow while moving to keep the operating temp at 176, far below my fan settings. The operating temp is fine in warm weather, running 185 to 190's with the air on in the summer and never a code (over 10,000 miles) until this winter. I'm sure if I lived where you do, there would be no codes.
Location: Baton Rouge, Louisiana = warmer than most Why not just drop in your stock stat. for the remainder of winter.
Yes. Motorad 4128 (rebranded as Valu-Craft at AutoZone -- also part #4128). Real live 185* tstat. Put it in a pot of water and check it. I think you'll find it opens at 185*. Mine does. When it gets really cold here (40*) the lowest the car will run at going down the freeway is 186*. I think you're right on your assumptions. Car needs to get over a threshold that's somewhere between 167 and 177 degrees within some amount of time after key-start. If it fails to do so for some number of key cycles it will throw that code. Your t-stat is a 176 (probably a 175 actually). That's why the car runs at a constant 176 all the time when it's cold outside. I doubt that your fans turn on at all so moving them up probably won't make a difference. You could do like the truckers and put a piece of tarp over the front of the radiator
You probably don't need to measure with a thermometer... When you're swapping them in the car just throw both of them in a pot of water. The 175 should open first and close last. Unless they're right together the motorad should be just fine.
I kew that I didn't have a fan isue, car only has 16,000 on it this week...it's so cold here, I could probably have sold Chase my fans, won't need them for months!
Exactly the same as mine, even the same part number. I have never thrown a temp code and I have driven my car at -25 degrees F startups for many days in a row.
Well, that is encouraging...maybe the new stat will work as i hope, now to wait for a day above freezing to swap it out. What temps are your fans set??
I think 191/199, and as I remember the medium speed fan setting means nothing, or something like that so I think I set the MS fan to 199. I just made sure and set them higher than my car normally runs based on the T-stat. FWIW, I flew into Cincinatti to pick my car up after shipping my car to DCXDepot a few months earlier. The day I arrived, I was left standing outside their shop after the dyno that day, with my car, when they closed up shop. The idle was set to 1700 and the fans were set to come on at 170 degrees F or something like that, which meant they were on the whole 22 hour drive home. That was fun at the gas stations "idling" around as I made my way home. ^^^Sore spot to say the least considering what else was fu$@ed up.. All I can add is that I have never thrown a code for coolant temp or anything else, and I start my car up whenever I need it, regardless of ambient temp...and I have some COLD temps in Wyoming.
Correct on the MS fan. We don't have that. That's exactly where I have mine set too. In the summer the high speeds only kick on occassionally and the low speeds are off about the same amount of time they're on. It was the right balance for keeping the temps from getting out of hand and hearing the fans running
