Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - Bubbling in Overflow Reservore Related to Code P0118?

Hatchtastic · 08-10-2011, 03:27 AM

Bubbling in an overflow tank has several causes: faulty radiator cap, stuck closed thermostat, faulty water pump, air pockets in the system (turn your heater on when bleeding it), blown head gasket.

I don't think that your P0118 would have anything to do with this, since it is an electrical circuit fault, and air bubbling in your overflow is a mechanical cooling system problem. The PCM uses the ECT sensor to determine fuel trims, closed loop, etc. If there is a problem with the ECT sensor, it may be staying in open loop, and you will notice a drop in fuel economy.

I fixed a car today that had a stuck closed thermostat, incidentally. Boiled a bunch of coolant out within minutes!

08-10-2011, 03:27 AM	#2 (permalink)
Hatchtastic EcoModding Lurker Join Date: Sep 2009 Location: Colorado Posts: 28 'Stache Builder - '92 Honda Civic VX 90 day: 42.58 mpg (US) White Dwarf - '09 Mazda 5 90 day: 28.87 mpg (US) Thanks: 1 Thanked 4 Times in 4 Posts	Bubbling in an overflow tank has several causes: faulty radiator cap, stuck closed thermostat, faulty water pump, air pockets in the system (turn your heater on when bleeding it), blown head gasket. I don't think that your P0118 would have anything to do with this, since it is an electrical circuit fault, and air bubbling in your overflow is a mechanical cooling system problem. The PCM uses the ECT sensor to determine fuel trims, closed loop, etc. If there is a problem with the ECT sensor, it may be staying in open loop, and you will notice a drop in fuel economy. I fixed a car today that had a stuck closed thermostat, incidentally. Boiled a bunch of coolant out within minutes! __________________ 1992 Civic VX