[locolobo]

I have been working on my 335d to give it the best TLC since purchasing 18 months ago with 32k miles. I now have 49,500 miles and I recently noticed that my car always runs at 80 degrees C (in the Torque app). No matter how hard I ran it, it would not go above 82C.

Several posts in the UK forum indicate this is not normal. The thermostat should open and maintain 88C - 92C when warmed up. I purchased one from BMW of South Atlanta and sure enough the metal part is stamped 88C. Note that they sent me 3 extra gaskets they recommended but were not needed. The new thermo comes with one o-ring for the smaller hose and the block gasket. The only one you need to buy is for the lower, larger hose. I just re-used the old one, though and it was in good condition, since they didn't send me a new one.

If you have ever done any work on your EGR system then the install is simple. (See other posts for this info). Remove the airbox, disconnect and remove the EGR cooler, pull off the retaining clips for the coolant lines, unbolt the thermostat integrated into the housing. Installation is the reverse of removal. It took me about 2 hours.

I did not drain the entire system and ended up losing about 5 liters of coolant, which I replaced with NAPA 1EXT extended life coolant (50/50 with distilled water). The OEM coolant is blue, FYI, and the NAPA is green. It's guaranteed to mix with all makes and models and cost $13.00 for a gallon.

Now I am am up and running at 88C. I hope this repair will result in improved fuel economy.