Volvo Repair: Fluctuating idle, volvo v70 t5, volvo v70 t5, volvo v70

Question
Hi james.
I have recently aquired a 1999 (november) volvo v70 T5.
when the engine has gotten up to normal temperature the idle RPM fluctuates between around 600 and 900.
I have replaced spark plugs to no avail.
I have been told to clean the IAC valve but havnt a clue where it is so any pictures etc would be much appreciated.
Performance seems fine, no loss of power etc.
i have also been told to clean the throttle body, could this be done myself (i have a haynes manual) or would i have to get volvo to do it.
i have also been told to get some codes read, but this could cost a lot?
kind regards
James

Answer
Well first there is no IAC valve.  Since the throttle is electronically controlled (no throttle cable) the throttle module controls the idle by opening the throttle blade.  Most likely a cleaning would correct the problem.  To get to it you need to remove the piping from the intercooler to the throttlebody.  The throttle body is under the intake manifold in the center.  Once the pipe is off, scrub the plate and channel clean with a rag and some carburetor cleaner.  You may find it easier to remove the throttlebody to do this.  It is held in by 4 10mm bolts.  If that does not correct the problem then the most likely culprit is a failing throttlebody module.  That part has received an extended warranty by volvo to 10 years, 200,000miles.  If nothing else fixes it take it to a dealer and if the codes are stored for throttle failure it should be repaired at no cost.

James