Turned the defrost on and heat on last night on my way home…temps dipping into the 60s outside. Started to get a weird musty noxious smell and my heat was blowing cold…unless it had it set to max high temp on the temp controller, at which point it blows nice and hot.

thoughts?

 

Just saw some coolant drips on the ground,
coolant expansion tank is also low. Hope it’s not the heater core

 

Okay, so the heater core has in practice constant flow through it.

Symptoms of an obstructed or blocked heater core include lukewarm air on the left side of the vehicle while the right side tends to have a warmer temperature.

The smell you describe isn’t usually the core’s fault, unless it is really a sweet smell which would indicate you’ve got a coolant leak in the cabin, but probably bacterial or similar growth in the air ducts or a wet/damp cabin air filter.

To troubleshoot the latter, take a look at the cabin air filter first and replace if necessary. There are also foams (etc.) available to clean and disinfect the air ducts.

 

Definitely not the heater core. No coolant smell or wet carpets on the interior, no visible leaks where the lines go from the engine compartment through the fire wall. Took off the engine cover, underbody protection and the small plastic covers between the wheel well covers and engine - looked around extensively and didn’t see any visible leaks at the hoses.

Went for a road trip to get the engine up to temp (kept climate control off). Parked and coolant was leaking from somewhere above the oil cooler. Appeared to be a few ounces of coolant. Return trip home and parked…no leaking.

intermittent coolant leak?!

 

Update!

the rover started making a weird whinning noise and shutdown while driving…dash lit up, all the warning sensors and messages were displayed, locks were furiously locking and unlocking, park break engaged…etc. vehicle wouldn’t start or turn over, completely dead. Electrical burning smell coming from engine bay. Jumped it but wouldn’t stay on. The alternator is definitely dead. When jumping, the cables got hot. It drained the tow trucks battery jump packs really fast (they kept the car running to drive it on the flat bed with the jump packs attached).

dies everyone agree the alternator is dead? Related to leaking coolant?

also noticed the wires of the this electrical connector on top of the engine were brittle and broken. Are these fuel injector wires? The engine was running smooth and getting great gas mileage.

 

Update, replaced the water pump, very easy job other then the coolant mess from draining. Two pieces of advice, keep the belts on when removing the pulley bolts, and get a vacuum coolant tester/filler. Both of these will speed up the process and make life easy. I bought this vacuum tool: OEMTools 24444.

after install, I drove for 30 mins around the neighborhood to get the coolant up to temp and everything checked out fine. I’ll check fluid levels in the morning.

obd II live values after 30 min cruise and T-stat opening up.