Enes : Hello and welcome to our web page here my name is Enes I'm a Certified Volvo Car Expert Mechanic.I'm going to try today to answer your question.
Enes : The valve you talk about can make noise clicking type for short time to run self test most the time at start up cold
Enes : Now that valve is called turbo control valve
Enes : the maf sensor what type did you use orginal from volvo ?
Enes : did you clear codes after repair ?
Enes : did you re check codes after repair ?
JACUSTOMER-4vhwll2r- : I used a Bosch part. The car has no power and I haven't noticed the cocking noise before
Enes : Did you use VOLVO dealer part ?
Enes : how much was that one.
JACUSTOMER-4vhwll2r- : No
Enes : 80% time all maf sensor sold out there are bad made or just wrong for volvo
Enes : volvo maf sensor cost close to $350
Enes : Now to know if you have good maf sensor you must use VOLVO advanced scsnner to illuminate the guess on maf
Enes : advanced scanner can read air flow thru and graph flow
Enes : You will have to that
Enes : than you can see if that is good maybe other problem is there
JACUSTOMER-4vhwll2r- : I paid $300 for Bosch maf from reputable motor factor (the original maf was a Bosch)
Enes : I'm just saying 80% out there from report poeople who come here online. Ends up to be bad maf sensor or wrong type
Enes : now you can have good maf sensor but you still gone have to use advanced scanner to monitor all other sensors how they work and maf sensor
Enes : Bosh makes maf sensor for all cars
Enes : You can have other issue maybe mad fuel pressure or throttle also
JACUSTOMER-4vhwll2r- : Assuming I have a good maf is there anything I can do without bringing it to a man dealer to reset the engine system service light? Do I need to drive it for a while for it to get clear readings. I had read about the etm but was this for earlier engines?
Enes : Throttle. Fails on your model also fuel pressure and sensor. Requires pressure gauge and scanner
Enes : all said you must use scanner or you will guess again $300 part to try
Enes : Without confirmed testing you will be guessing
Enes : but bad part is you can't do much at home with no scanner
Enes : Reset of check engine must be only reset with scanner
JACUSTOMER-4vhwll2r- : My engine system service light used to come on under heavy acceleration then go off maybe 24/48hrs later? Would disconnecting th battery for a while do this or reset the codes?
Enes : Don't do that you erasing all codes you must know all codes that stored before you disconnect battery do you know problem area
Enes : If you just clear it out it will happen again and can damage more
JACUSTOMER-4vhwll2r- : Will I damage eng e by continuing to drive?
Enes : It can create problems
Enes : engine will not brake that easy
Enes : but can create brake more parts. If you had the codes from scanner I could tell you more
JACUSTOMER-4vhwll2r- : I have an ob11 scanner would that give you the codes?
Enes : You can give me if you have obd2 scanner it can give idea to what is going. On
Enes : Reply back with codes when you check