A/C - Insufficient Heat Output, Clean Filter Screen
84bmw03GROUP 64 Heating and Air Conditioning
Bulletin Number 64 07 84 (850) Page 1 of 1
Montvale, NJ November 1984 Technical Dept.
SUBJECT: Heating system complaints
MODELS: 528e, 533i, 633CSi
Complaint: Insufficient heat output.
Cause: Reduced coolant flow rate due to clogged up filter screen in water valve; caused by dirt in the cooling system (oil in coolant, casting residues or nonapproved coolant additives.)
Correction: Remove water valve and thoroughly clean filter screen (arrow).