Driving a '99 TJ with 186k miles, which we just acquired. We found that the heater will not get hot, and have done some troubleshooting.
The hoses to and from the core don't get hot, but when I disconnect them and flush with a garden hose, there is water flow both directions. The first time I did it, the water that came out wasn't pretty. Water in radiator was nice and green, and the guy I bought it from said he had replaced the radiator recently. I figure he didn't flush the system so the heater core was clogged. Flushed both directions until water pretty much cleared up. Put it back together, but it didn't solve the problem.
Why would a heater core that allows water to flow through in both directions not get hot? I thought the connections to the block might be plugged, but they aren't. I can get water from the inlet hose (disconnected from thermostat housing) through the heater core, back to and through the water pump, radiator or block and back out the pipe that the hose attaches to.
I connected the supply hose back to the thermostat housing and disconnected the return to the pump to see if I could get water out the return hose. Connected a piece of scrap garden hose to the pump return line and elevated it above the radiator fill neck so the system would stay full except what comes through the heater core. Filled radiator, then start the engine. The water circulates from the block to the radiator (top radiator hose gets hot) but there is no flow coming out the heater core return hose.
How is this possible? Bad water pump? Water pump installed wrong? Bad thermostat? HELP!!!!
The hoses to and from the core don't get hot, but when I disconnect them and flush with a garden hose, there is water flow both directions. The first time I did it, the water that came out wasn't pretty. Water in radiator was nice and green, and the guy I bought it from said he had replaced the radiator recently. I figure he didn't flush the system so the heater core was clogged. Flushed both directions until water pretty much cleared up. Put it back together, but it didn't solve the problem.
Why would a heater core that allows water to flow through in both directions not get hot? I thought the connections to the block might be plugged, but they aren't. I can get water from the inlet hose (disconnected from thermostat housing) through the heater core, back to and through the water pump, radiator or block and back out the pipe that the hose attaches to.
I connected the supply hose back to the thermostat housing and disconnected the return to the pump to see if I could get water out the return hose. Connected a piece of scrap garden hose to the pump return line and elevated it above the radiator fill neck so the system would stay full except what comes through the heater core. Filled radiator, then start the engine. The water circulates from the block to the radiator (top radiator hose gets hot) but there is no flow coming out the heater core return hose.
How is this possible? Bad water pump? Water pump installed wrong? Bad thermostat? HELP!!!!