Sammo 2544 Report post Posted February 9, 2020 So was giving my 330ci some love this weekend (oil, filter, plugs). This is the first time I've changed the oil and plugs on this car, so not sure of its history. Anyways, when I pulled the Spark plugs, several had a decent amount of oil on the threads (one particularly so) and most were a bit wet and sooty. The ignition coil boots however had no oil at all, even the one connected to the oiliest plug. A bit of googling has me thinking it could be the Valce cover gasket leaking, but given the coil rubber boots were dry, I'm not sure. Car showed a few misfire codes several weeks ago (P1342, P1346, P0300) but after I cleared them they have not come back. Car had been feeling a little sluggish, nothing obvious but is running great now with the new plugs and no codes - if its a leak I imagine it will be a matter of time before the issue manifests again. Pics below, including the plug wells. Car has been using a fair bit of oil (2 litres in 4000km) but that isn't unusual for an M54 from what I've read. Quote Share this post Link to post Share on other sites
KwS 2425 Report post Posted February 9, 2020 Id say the spark plug tube seals are starting to leak, but not yet bad enough to be on the coils. Rocker cover gasket should sort them out. Those plugs looks super worn out with massive gaps too. 1 Quote Share this post Link to post Share on other sites
Sammo 2544 Report post Posted February 9, 2020 4 minutes ago, KwS said: Id say the spark plug tube seals are starting to leak, but not yet bad enough to be on the coils. Rocker cover gasket should sort them out. Those plugs looks super worn out with massive gaps too. Thanks mate, yeah, car definitely felt better with the new plugs in. Will tackle the valve cover gasket in a few weeks then check the plugs again a month later. Been freaking myself out googling valve stem seals the past half hour ? Quote Share this post Link to post Share on other sites
Sammo 2544 Report post Posted February 29, 2020 On 2/9/2020 at 5:56 PM, KwS said: Id say the spark plug tube seals are starting to leak, but not yet bad enough to be on the coils. Rocker cover gasket should sort them out. Those plugs looks super worn out with massive gaps too. Yup, you were right. A week after this post got the telltale burning oil smell and saw it was leaking onto the exhaust heat shield. Sprung for the BMW gasket and replaced yesterday, was particularly brittle on the plug seals. New plugs had a little oil on the threads already, so cleaned them up and everything else. 1 Quote Share this post Link to post Share on other sites
