ETM or Breather Box? 2001 Volvo S80
 

Forgive me as I've seen a similar post on this topic on the forum, but my question is slightly different. My car has been surging in a "cycling" way at idle. it's 2001 with about 115,000 miles.

My private mechanic tells me that this is 99% likely to be a failing ETM, which is covered under extended warranty.

Took to dealer who said ETM passes code check and anyway it's 98% likely due to clogged PCV breather box (because "I didn't change my oil frequently enough": bogus!).

While I believe the breather box work may need to be done, my question is this: is the surging, "cycling" idle consistent with a clogged breather box?

Thanks in advance for your response and for this wonderful forum

I'd try cleaning your ETM first.

here's how....

http://www.youtube.com/watch?v=8Zaxtm-hdyo