Replacement thermostat With Housing for B46 and B48
10X Entries Into Our F80 M3 Sweepstakes For vehicles with the earlier Gen1 B48/B46 only - not compatible with the later Gen2 B48 (TU) engines
Located on the side of the engine block, includes gasket. OE+ Upgrade over the original.
2X Entries Into Our F80 M3 Sweepstakes We Price Match - Give Us A Call or Chat! For vehicles with the earlier Gen1 B46/B48 engine - Not compatible with the later TU engines
OEM replacement thermostat with housing and gasket for B46 and B48.
For vehicles with the earlier Gen1 B48/B46 only - not compatible with the later Gen2 B48 (TU) engines
Brand:
ES#:
3198177
Mfg#:
11537644811
In Stock
8% off MSRP
MSRP stands for Manufacturer's Suggested Retail Price. This is the suggested retail price provided by the manufacturer, supplier or seller.
$602.99
This product was last offered at the strikethrough price on 11-05-2026
Includes the components needed to replace the two biggest B48 cooling issues, plus most of the "while you are in there" parts we highly recommend replacing - featuring an Aluminum Oil Filter Housing, Coolant Thermostat Module, and coolant pump assembly!
10X Entries Into Our F80 M3 Sweepstakes For vehicles without Energy Recovery System (S1CEA) For later models with the B48 Gen2 (B48D) engine only - Not compatible with earlier Gen1 engines
Brand:
ES#:
5425175
Mfg#:
G2XB48DOFHL2KT
Ships in 1 Business Day
ON SALE!
SAVE 15%
$1733.99
This product was last offered at the strikethrough price on 06-15-2026
Your engine relies on a steady temperature to stay healthy and efficient. With the Rein CTA0079, you’re getting OE-level quality and a frustration-free install that gets your car back to peak performance.
2X Entries Into Our F80 M3 Sweepstakes
Brand:
ES#:
5470515
Mfg#:
11537644811
Ships in 3 Business Days
$322.99
This product was last offered at the strikethrough price on 06-11-2026
Replacement thermostat With Housing for B46 and B48
2X Entries Into Our F80 M3 Sweepstakes We Price Match - Give Us A Call or Chat! For vehicles with the earlier Gen1 B48/B46 only - not compatible with the later Gen2 B48 (TU) engines
Main cylinder head gasket 1.00MM (+0.3) (plus size)
2X Entries Into Our F80 M3 Sweepstakes For vehicles with production from 07/2015 with the B46/B48 Gen1 engine
Brand:
ES#:
4940647
Mfg#:
597.170
In Stock
Limited Qty Sale
$134.99
This product was last offered at the strikethrough price on 11-04-2026
Includes the main components needed to replace the two biggest B48 cooling issues - featuring an upgraded Aluminum Oil Filter Housing and new Coolant Thermostat Module
10X Entries Into Our F80 M3 Sweepstakes For vehicles without Energy Recovery System (S1CEA) For later models with the B48 Gen2 (B48D) engine only - Not compatible with earlier Gen1 engines
Brand:
ES#:
5425168
Mfg#:
G2XB48DOFHL1KT
Ships in 6 Business Days
ON SALE!
SAVE 22%
$1106.99
This product was last offered at the strikethrough price on 06-15-2026
$861.46 USD
Free Shipping
on orders $49 and up
Partial Replacement
More About Engine Coolant Flanges & Parts
Replace a cracked or failed coolant flange with a brand new coolant flange to stop those leaks!
Lifetime Replacement
