2008 Rogue Almost No Heat

[451stroker]

Hello,

I'm working on a 2008 Rogue that has almost no heat. The thermostats have been replaced. I've bled the system of air. When it reaches operating temperature, the lower radiator hose is cold, and the upper hose is hot. After about an hour of running, the lower hose finally gets hot and the heat is acceptable. So basically, there's no heat for any around town trips. You have to drive the car for almost an hour to get heat.

Does anyone know why the lower hose is cold and the upper hose is hot when the gauge indicates that the engine is at operating temperature? The system has been bled more than once, and the fact that the lower hose eventually gets hot and I get heat after an hour makes me pretty sure that there is no air in the system.

Any help would be greatly appreciated.

Thanks!

[ImStricken06]

sounds like radiator is clogged. drain it, refill it, and see what happens. Have you filled the system and started the engine with the radiator cap off? See if system circulation is there?

[451stroker]

sounds like radiator is clogged. drain it, refill it, and see what happens. Have you filled the system and started the engine with the radiator cap off? See if system circulation is there?

There's no circulation for the for almost an hour. At some point, I have to put the cap back on because it'll spill over. There's definitely circulation once the lower hose gets hot though. But, even when the lower hose finally gets hot, the heat isn't great, it's just okay. Does that sound like a clog?

[451stroker]

I should clarify that my friend brought me the car after he had a service station change both thermostats, the water pump, and flush the system in an attempt to repair the no heat condition. All I have done so far is run the engine with one of those giant funnels to bleed it, and I also observed the cold lower hose after the engine was at operating temperature.

Why are there 2 thermostats? Is it possible that the lower thermostat is taking too long to open and that's why the lower hose is cold? The service station replaced both thermostats in an attempt to fix the problem, so I doubt that the new ones are faulty. Would removing the lower thermostat solve the problem, or cause new ones?

Thanks!