I keep getting a p0128 code
Coolant Temperature Below Thermostat Regulating Temperature

I put a new temp sensor in yesterday and that didn't fix it. what else could it be ? from what I read it uses the maf to calculate the outside air temp as well to get whatever value it needs. or am I reading this wrong? anyone have any ideas
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I should add I still get a coolant temp reading, thermostat still opens and fans still come on when they should. car doesn't heat up any faster than normal. same thing. nothing has changed except for getting that code.

 

I'm not sure if the lnf is just as bad as the l61 but my old base model needed a thermostat for this code. Inner seal on the thermostat was worn and leaking when the thermostat was closed.

 

Grab a oe thermostat, common issue like other guy said. inner seal breaks and allows too much coolant to flow not allowing the engine to properly heat up. the ecu has a timer that the engine should reach a certain temp within a certain time based on outside ambient air.

 

Ok thanks guys. Is the one sold by zzp oe? And will I need to drain coolant?

 

Don't you have HP Tuners? I disabled that code long ago. This is because if your car doesn't reach a certain temp in a certain amount of time, the computer assumes your thermostat is failed (they fail open) and ignores the reading entirely. If you're someone like me who revised his fan settings or lived in a cold-ass place, you'll get this code no matter what. That's why I disabled it, and every ZZP tune I've seen has this disabled. I also noticed that when I switched to synthetic, and more specifically 5W20 a very long time ago, the car got this code a lot more often.

BTW, by OE just make sure you get the 195* thermostat. Anything colder and it will constantly set the code.

 

I don't have tuning experience, but I'm 95% sure the LNF fan settings are different than the 2.2 motors'. Getting a 195° tstat could be annoying (fan on/tstat closed/etc) unless you change the fan settings accordingly... but if you did that may as well keep it cooler with the 180° tstat.

 

If you replace the tstat you will need to drain the coolant.

 

I live in cold ass place to and have never had that code pop up till recently. ill change the thermostat and if its still does it ill disable it

 

It is a lot more complicated than that, but the lnf and L61 are only marginally different. The motor still operates off a xxx* by x amount of time. The fan controls aren't on/off but rather go by percentage depending on coolant temp. At 210* coolant temp. The fan is only doing 31% capacity. At 196*, it's only 6%. So really the fan doesn't have much to do until much higher temps unless you modify them. These thermostats also don't work like the SBC used to. They are much more efficient.

 

Well in 100% it's the tstat. I have a gauge, prob is in rad hose, the gauge starts at 100f and doesn't go up till car warms up to 180 and tstat opens, then it goes up to 180, now it goes up past 100f = to engine temp on the cars readout. So it's stuck open. Car takes forever to warm up