147 JTD misfire
So as the title suggests, I've got a misfire on my new (to me at least) 147 JTD, 2005 w/ 89,000 miles clocked. I 'think' it's a 16V model seeing as it says 150bhp on the reg cert but the 5 speed gearbox seems to hint otherwise.Anyway, brought it down to my local trusted Indie garage and he tells me there's a misfire on cylinder 4. He's checked injectors by swapping the one on cyl. 4 with the one in cyl. 3 and it fires just fine in cyl. 3, but still getting misfire in 4. Checked electrics and connectors, all good. He's thinking it's a compression issue now so he's waiting on the equipment to do a compression test early next week. What I want to know if any of you had this problem before? Mech's reckoning it's a swirl flap stuck open, I'm hoping it's just EGR (which is unlikely seeing as only the 4th cylinder is misfiring) and general forums are saying it's a head gasket leak. Honestly, I'm hoping it's just a swirl flap because those were due to come out and get blanked anyway but if it's something else, I'm in the deep end seeing as she already needs a new clutch (maybe even a DMF!) and a timing belt and w/pump done too..
Any info is appreciated and thanks for all the help people!