2001 V70 T5 w/ 140,000 miles. I do the maintenance and minor repairs. About 1,000 miles ago, after reaching normal operating temperature, the engine began surging after coming to a full stop, 500-1,000 rpm and a CEL. No surge while driving or when engaging the turbo. Hooked up my OBDII reader: no codes, turned off the CEL. If I turn off the engine when its surging and restart the car it "resets" and is fine until a bit later when coming to a a near or full stop. If I hook up my OBDII reader to the engine while its surging and press "Link" and then "Erase" the CEL clears and the rpms go up to 1,000 before settling down to around 750.
I did some research on this and other forums, pulled the throttle body and gave it a careful and thorough cleaning, installed a new gasket: no change. Suspecting it might be the wiper in the ETM, and figuring to solve THAT issue once and for all, I bought the XeModex ETM and installed it: no change. A little more reading and I ran across mention of the Turbo Flow Valve. Some symptoms were similar so I bought ipd's upgrade and installed it (couldn't hurt): no change.I've also replaced the MAF & IAT sensors. At this point, rather than continue the shotgun approach, I figure I'll ask for help.
Anyone have any insight into this sort of idle surge and the attendant fix?
All constructive commentary sincerely appreciated.
