I bought a 2012 Hyundai IX35 1.7 diesel for my missus which had been off the road for 3 years, only 36k miles with full service history to back it up, and had a suspected head gasket issue (pressurising coolant). My and my mechanic mate Tom replaced the head gasket and head bolts, put it all back together and was running great. After a couple of weeks use and about 500 miles it started making some noise when warm, and had an oil leak at the turbo oil feed/return flange so I removed the turbo, fixed the oil leak with a very light smear of silicone gasket (high temp stuff for exhausts), and tried to remove the injectors to remove the rocker cover to check everything was ok under there. Could only get the middle 2 injectors out but noticed quite a bit of oil down the shaft of one, and at the tip. I put them back in, connected it all back up and the engine ran fine for 2 days without issue. 3rd day and it sounded like a tank, and I was pretty sure there was an exhaust leak at the turbo cos that’s what it sounded like. No exhaust leak there, and a hefty smell of diesel smoke in the engine bay.
So worked out the oil seals around the top of the injectors probably need replaced, have ordered them from Hyundai along with injector seals (copper washers) and all other gaskets for the injectors. Currently waiting for them to arrive, although I’m sceptical that the problem/noise lies with the injectors. Engine sounds fine when cold, then once it’s warmed up after about 10 mins driving it sounds like the engine is about to die. Still pulls strongly though, feels absolutely fine, oil level and grade are fine, and no warning lights on the dash. Also the noise goes away under acceleration. It’s mostly obvious at idle, off boost and on overrun.
Anyone got any experience with these engines?