Hi its me again. Good news and bad news. The good news is that it looks like the mass air flow problem has been finally solved. The bad news is that my check engine light came on again yesterday! This time its P0128, something about the coolant temp being less than the thermostat regulating temp.

I had this code come up a couple of weeks before, but got it cleared with my other codes(refer to the earlier probs!). While the air flow codes came up again, this coolant temp code didn't. Not until yesterday again. I've read up abit and it looks like I've either gotta change my thermostat or the coolant temp sensor. Which step should I take, or should I just change both? If I do change the thermostat, will getting the 87deg one be better?

Lastly, which 1 will require more mechanical labour? Cause if its related I might as well just change both at the same time so I don't have the pay the mechanic twice to fix it if 1 method or the other don't work.

Thanks for reading!

 

Oh yeah, something to add. The temp gauge shows normal. Once the car warms up, the needle points to about the middle, so I don't think theres a problem with the coolant system.

 

Sounds like it's a faulty coolant temp sensor. It's in the t-stat housing. Very easy to change. IF you are changing the temp sensor you might as well put in a t-stat while your at it. Just follow the upper radiator hose into the head and there is the t-stat housing. It's pretty self explanitory from there.

 

Is the sensor located in the thermostat housing as well? Do I need to remove any other components before I can open the housing?

Lastly, which thermostat should I get, the 87 or 90 deg one? I'm in Phoenix Arizona and the average temp is about 60-80 deg in the winter and 90-110 in summer.

 

I just realized that in my last post, i asked the exact same question which ihatespeedbumps already had the answer for!

Still dunno which thermostat to get, 87 or 90 deg? What's the diff, technically?