coop 261 Report post Posted July 2, 2015 Who here has done this with success? Any performance/efficiency gains? I did it with my E46 a few months ago. First long drive there was no noticeable performance or economy improvements, just no smoke holding her flat. Just had a look under all the covers this week and it looks like the cooler is now leaking coolant at the output clap leading to intake manifold. I assume hot exhaust gasses end up being trapped inside the cooler with no where to go, rupturing the cooler, pressurizing the cooling system and allowing coolant to leak into the exhaust port when the engine isn't running. Think I may order a new cooler and fit the original vale back in there. Quote Share this post Link to post Share on other sites
