It's no secret among 335 owners that while the cars perform admirably, they tend to run a bit on the warm side. This appears to be true even with the cars equipped with the factory oil cooler; and in case you weren't aware, not all 335's came with an oil cooler at all! For those who drive the cars in a spirited fashion on a regular basis, this issue is even more pronounced. While this is certainly a concern in stock form, it becomes even more of an issue when you consider increasing boost pressure, which in addition to added power output also generates more heat. And when you back your products with matching new car warranty coverage, including consequential damages, you tend to be a bit more concerned about the real-world ramifications of increased turbo boost pressure on the car as a whole.
Recognizing the significance of this issue, Dinan set out to develop a more efficient heat exchanger, ultimately in the form of a High Capacity Oil Cooler. Two complete systems have been developed, one for vehicles that weren't equipped with a factory oil cooler and the other as an upgrade for the stock unit. Now every 335 driver has the opportunity to lower operating temperatures significantly, providing peace of mind as well as avoiding that notorious "limp" mode when things get simply too hot.
The Dinan High Capacity Oil Cooler provides literally twice the volume of the stock unit, as well as 414 sq./in. of cooling tube vs. 112.5, and that's really just the beginning. Nicely integrated inlet ducting provides greater airflow efficiencies and the ventilation of air to the fender well has also been improved with a larger outlet. The system mounts neatly in the stock location and includes lightweight PTFE hoses with polyester outer braid fitted with race-quality fittings. For cars that were not equipped with the factory oil cooler, kits are available that include all of the additional parts necessary for the installation.
The results of the oil cooler upgrade are quite significant, with the temperature gauge holding steady even under high load/high boost scenarios. And for those of you who track their cars, even occasionally, the Dinan oil cooler is a must.
NOTE: Some 335 Sedans, typically those with the Active Cruise Control feature, were equipped with a longer fog light that will not clear the oil cooler. This type of lamp can be identified by the plastic lens (the more typical lens has a glass cover with a part number on it). In these cases, the right (passenger) side lamp will need to be replaced with BMW part no. 63 17 7 158 542 which is a direct replacement and easily clears the oil cooler. Only the right side requires replacement. Dinan stocks the replacement lamps if required.
More total volume: Stock - 9.5 oz. vs. Dinan - 19 oz.
More surface area: Stock - 45 sq./in. vs. Dinan - 67.5 sq./in.
More cooling tubes: Stock - 10 vs. Dinan - 23
More tube length: Stock - 90 in. vs. Dinan - 207 in.
More tube area: Stock - 112.5 sq./in. vs. Dinan - 414 sq./in.
Dinan Point Value
Labor Time (Hours)
This part is legal for sale or use on Emissions Controlled Vehicles, Uncontrolled (Non-Emissions Controlled) Vehicles, and Racing Use Only Vehicles because it does not affect vehicle emissions and is not covered by emissions regulations.