View Full Version : P0128 persists even after dealer fix

06-20-2012, 10:33 AM
Every post I go to says that the P0128 code is "Coolant Thermostat (Coolant Temp Below Thermostat Regulating Temperature)". I got it! So I brought it to the dealer to replace the thermostat. Of course they found other things that needs attention so after all was said and done, I was $2500 poorer.

It's only been a month and now the service engine soon light is back on. It's the same P0128 code. Coolant level is normal. Im taking it back to the dealer in a couple of days for who knows how much again.

Is this because my work is only 3.5 miles from my house? Which causes the engine not to heat up enough by the time I get to work? My other cars seem to hit normal operating temp a couple of minutes before I arrive at my work place. And that's in the dead of winter. This is my other gripe about the 07 E60 model - why is there no temp gauge? It's mid 90F here in Indiana for the last 3 weeks now, so I think it would heat up enough after 10 min of driving.

Can somebody please give me some input so at least I can be better equiped with some wisdom before I take her to the dealer?