Do these do a "self clean" on the 3L V6? Reason for asking is I put the battery back on mine yesterday[I'd took it off to charge it]started the car and let it run for a short while[didn't drive it anywhere]while checking other stuff a few seconds after turning it off there was a noise I can only describe as a Brrrrrr sound for a second or two.So I started car again and on turning it back off it did the same.I don't recall hearing this noise before,but I do know that although it's a different sound and a totally different vehicle/engine that Transits do a self clean of the egr valve and just wondered if this was the same or what else it could be.Rev counter still didn't work[although the needle quivered when I turned ignition on all the warning lights came on/went off as they should and fuel temp gauge worked,but that's a separate issue isn't it?