# 335d EGR Cooler



## diapason8 (Jul 1, 2011)

My 2011 335d (174,500 miles) has had a slow EGR cooler leak but only just recently got an SES light - code (P2457) indicated EGR cooler function error. 

I took a close look at the EGR cooler and noticed that there is a valve actuated by a vacuum device on the intake end of the cooler. There appears to be a spring on this valve that has broken. In reading online, this sounds like a common fault but one that requires replacing the entire EGR cooler.

Question : Does this valve regulate the flow of exhaust gas into the EGR cooler or does it regulate the flow of coolant?


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## Doug Huffman (Apr 25, 2015)

The throttle valve regulates exhaust gas flow.


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## diapason8 (Jul 1, 2011)

Thanks - does anyone know of any documentation that describes the EGR cooler function and the circumstances under which the vacuum control actuates and what it actuates? 

Also, anyone ever replace one themselves? I found a procedure online and it doesn't look too bad, but was curious if anyone has given it a try.


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## Doug Huffman (Apr 25, 2015)

diapason8 said:


> Thanks - does anyone know of any documentation that describes the EGR cooler function and the circumstances under which the vacuum control actuates and what it actuates?
> 
> Also, anyone ever replace one themselves? I found a procedure online and it doesn't look too bad, but was curious if anyone has given it a try.












https://www.bimmerfest.com/forums/attachment.php?attachmentid=879835&stc=1&d=1579995792


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