BMW E32 heater core leak and replacement
E32 how to tell if the heater core is leaking?
There is a sweet glycol smell in the cabin, the windows fog up with a sticky film and the floor or its insulation is wet. You can tell the film from water by taste: glycol is sweet. The smell can fade even though moisture remains in the air ducts and the carpet.
Can an E32 heater core leak be sealed with a leak sealer?
Not advisable. Sealer can clog the cooling system and damage the engine block heater. A leaking core is replaced with a new one, and the cooling system is bled after the job.
How is the E32 heater core replaced and what should you note?
The core comes out through the driver's footwell after removing the panel and plastic trim pieces under the steering wheel, or by opening the air conditioning box. The leak may be only in the O-rings of the pipes, so check those first. Clean the air ducts thoroughly and take photos while dismantling.
Can E32 windows fog up for reasons other than a heater core leak?
Yes. The air recirculation may be stuck on, the boot air extraction vents blocked or the windows dirty. Leaves and debris collected in front of the core can also cause fogging.