Wife's GC threw a p0128 code about 3 weeks ago when outside temps were 20 to 30 degrees. Says thermostat is opening to soon I believe is what the code is. So I bought a new stock one to replace. After pulling thermostat off jeep I realized it has a low temp mishimoto 180 degree stat installed. So I re installed low temp stat and drove jeep to monitor coolant temps.. Stat seemed to open after 180 but stays between 175 to 200 degrees even when getting on it and seems to be working just fine. Jeep threw that same code again yesterday and outside temps have been a little warmer mid 30s to 50s. Any ideas?
Thanks fellas

 

Moved thread.

 

Really no replies? Fellas.. Dealing w my duramax is alot easier than the jeep. Duramax forums better too

 

MOST people on this forum aren't driving anything that new, so chances of getting a response are more limited. My own opinion is it's running too cold and you need a higher thermostat like a 195*

 

X2

This isn't GRAND Cherokee forum. Lol

When it comes to the newer stuff this forum gets pretty slow.

NAGCA comes to mind as a place to try, but I've never owned a GC so I don't know how helpful they are on there.

I agree, you need to put in a stock thermostat (from dealer only) and see what happens before going further.

 

Haha I figured there wouldnt to many gc guys. I will install stock t stat,clear the code again and go from there. Not a huge fan of the wifes jeep ha. Thanks for replies fellas.

 

Well, the forum is full of XJ, ZJ, and WJ guys, but not too many WK or WK2 guys.