Not sure what yr your Frontier is, but:
Are you running the original stock radiator...and IFF so, are you aware of the possible transmission-fluid/coolant cross-contamination issues associated w/ '05-'10? AKA SMOD?
Edit: I see you have an '07 Frontier...so, if you're auto trans then you'll want to look into this/SMOD.
Are you running the original stock radiator...and IFF so, are you aware of the possible transmission-fluid/coolant cross-contamination issues associated w/ '05-'10? AKA SMOD?
Edit: I see you have an '07 Frontier...so, if you're auto trans then you'll want to look into this/SMOD.