This is a radiator water tank cap produced for the cooling system of the flagship BMW 7 Series E65 / E66 (2001-2008) vehicles, made by BMW's original equipment manufacturer MAHLE (Behr). The massive engines of the E65, which operate under electronic control at very high temperatures (105°C - 110°C), require flawless and stable pressure in the cooling system. This part is not just an ordinary cap; it is a highly precise 2.0 Bar (200) pressure adjustment valve that prevents the massive engine from overheating. An old cap with a broken spring valve or a crushed gasket can cause the water to boil prematurely, leading to evaporation and a constant low water warning on the iDrive screen. Secure your "official vehicle" with MAHLE quality.
- OEM Quality (MAHLE/Behr): MAHLE, the world's largest thermal management and cooling system manufacturer, is the brand that produces parts directly for BMW assembly lines. Unlike cheap counterparts from China, the valve calibration is flawless and does not jeopardize expensive N62/N73 engines.
- Critical 2.0 Bar (200) Valve: When the pressure exceeds 2.0 bar, it releases excess air to prevent the system from bursting at a weak point (sensitive water tank or hoses), and when the pressure drops, it reseals the system to prevent the water from boiling.
- Sealed Viton Gasket: Thanks to its special lower gasket resistant to the intense heat under the E65's hood, it perfectly seals the radiator tank's mouth; this effectively prevents hidden water loss through evaporation.
- Solution for Swollen Hoses: If the massive radiator hoses of your vehicle swell like rocks when the engine heats up, it means the drain valve of your old cap is clogged. This original cap system provides immediate relief.
Technical Details
| Brand |
MAHLE (Original Equipment Manufacturer - OEM) |
| Product Code |
CRB22000S (Compatible with Old Behr Code) |
| Opening Pressure (Valve Value) |
2.0 Bar (200 is written on the cap) |
| Compatibility |
BMW E65 / E66 Chassis (Especially 730i, 740i, 745i, 750i Gasoline Models - 2.0 Bar Systems) |
| Possible OEM References |
17 11 7 639 022 / 17 11 1 742 231 |
Frequently Asked Questions (FAQ)
My E65 730d diesel vehicle has a cap that says "140", what happens if I buy this cap that says "200"? You definitely should not buy it. Diesel E65s (M57) use a 140 (1.4 Bar) cap for their cooling systems. If you install this 2.0 bar (200) cap on a 1.4 bar system, the pressure in the system cannot be released when needed. The vehicle's water tank, circulation, or hoses may not withstand this pressure and burst. Be sure to order the same number as on your old cap.
I am receiving a coolant warning on the iDrive screen, but there is no water dripping underneath. Could this cap be the problem? Yes, the under-hood of the 7 Series is hellishly hot. When the valve mechanism inside the cap fails, the pressurized boiling water at that temperature evaporates and escapes through the cap's drainage paths without being visible. You won't see a liquid dripping on the ground, but your water is secretly depleting. In cases of hidden water loss complaints, the first and most affordable part to be replaced is the radiator cap before those famous pipes and tank.
Why should I choose MAHLE instead of a cheap aftermarket cap? The V8 and V12 engines of the E65 do not forgive the slightest cooling weakness, and engine block revisions can reach enormous budgets. The spring calibration of aftermarket caps is inconsistent. It may open at 1.0 bar instead of the required 2.0 bar and spew water out, or it may not open at all and burst the system. MAHLE is the most robust original equipment that protects your luxury official vehicle from overheating damage.
