Hi Thank you for your question, my name is ***** ***** I am a fully qualified technician with over 30 years in the trade, I hopefully can help you.
The way you describe it I believe that the problem is with the ignition lock failing to turn the extra distance to activate the starter.
This can be a common problem on the Volvo's with the laser cut keys and could indicate that you may need to change the ignition barrel soon.
The solution in the short term (and this should work for a while) is to use a small amount of three -in-one oil on the key blade and a small amount put into the ignition lock where the key goes in.
The jiggling the key in and out to allow the oil to access the tumblers, should free it off.
I hope this helps and answers your question, but do please feel free to ask any further questions.
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