I was banned from parking in the carpark because my Zed was marking the parking spaces. The Zed would leave several drops of engine oil when parked. I haven't driven her much in the last two weeks but suspect she pisses a bit more than that while being driven. It drips from the lowest point between the engine and transmission. I followed the oil to the starter motor and looked under the starter motor heat shield but could not see any oil. The oil has a path around the starter motor. The oil starts coming out here. The pic shows oil coming out of the flexplate alongside the starter motor. I looked above the starter motor and higher up the engine, looking around the head gasket and higher but could not find a river of oil. I had the endoscope all over the hidden parts of the engine and decided to phone Niall BrisEuro. Reading threads on this forum, I am thinking Rear Main Seal. If Niall is doing the job, I can get a few Zed specific things done.
+1 for rear main seal. Mine was leaking from almost the same spot, stopped after I replaced the rear main.
Would a faulty PCV allow pressure buildup in crankcase and cause oil to be forced out the main seal? Is there a rubber hose somewhere that can be checked or pulled off a t-piece on NA engine to relieve a PCV problem? Another car owner mentioned this because I have a one hour drive to mechanic.
In my view, It is possible, but you would need both PCVs to be plugged plus very worn engine ie, bores, rings, valve stem seals. Run your car engine with oil filler cap off and see if there is any pressure. Usually find that when a rear main seal leaks, it never reseals again anyway
Rear main seal is getting replaced on Monday, I will ask Niall to check both those PCV. I see page 189 of the manual says to remove each of the PCV hoses? and put a finger over to check for vacuum. I don't know which hoses they are. Black ones ... http://www.wallpaperama.com/forums/how-to-replace-change-pvc-pvc-valves-on-nissan-300zx-turbo-non-engine-t421.html OK, I think I see one next to the engine oil dipstick, runs north-south with car, but I can't see the same on passenger side.
Hey mate, If I'm correct these are the ones that run into the upper plenum on both driver and passenger side, there are two PCV valves, one each side, they are located in the middle of the upper plenum on both sides with big thick black hoses on them, PCV valves face to the rear of the car so rubber hoses are facing front if that makes sense.
OK the thick black hose. Do these things need replacing or can they be cleaned / serviceable. I notice that pcv is on the list of 300zx deletes.
Can't just delete the PCV valves all together. The delete is actually blocking off valves and running catch can to the front 2 breathers and either atmo venting or recirc them into the intake with the catch can removing most of the oil out of the intake and subsequently the plenum. No more oil pooling at the back of the plenum after this. Can recommend it though, makes for a cleaner intake.
OK, won't be trying to delete. Hose off and finger test for vacuum. Found this picture in another thread on this forum.
I am not sure how they build these pcv valves, but if it fails the suck finger tip test, why not squirt some degreaser and 5 mins later, squirt some compressed air to unblock? Has anyone ever pulled one apart to find out why they fail? Is it just gunk that can be cleared or non metal parts that wear out?
Just Gunk, Yes you could attempt to clear them in situ, but remember where all that gunk will end up. Its not a big job to remove, clean and test them properly.
You would be right, not a big job, but battery needs to be out, cables/harness moved (disturbed) and spare hose needed as standby incase something happens. Started and decided not to because I am driving this leaking car in traffic to Rollin tomorrow morning so I want to make sure I don't stop it from starting. I checked oil level on dipstick. A little bit high. Your other suggestion about takiing oil cap off, I tried making the oil cap loose and see if any difference, Car got up to temp and idling for 30 mins. I could see the droplet from two days ago hanging there, but it didn't drop. Put some paper under car to make sure I catch and drips. So no drips for 30 mins when oil cap was loose. I revved it above idle and a minute later I had heaps of oil. A puddle. Don't be driving behind a White Zed tomorrow morning because there will be a trail of oil.
PCV valves checked by Rollin while he was fitting a new Main Seal. It was hardened and wasn't a Nissan OEM quality part. Lasted 6 years. There was an additional problem, the orange retainer gasket was also leaking. I'll post some photos after I have had a good look at the old parts.
I forgot to bring my replaced parts home to take photos and inspect. Rollin took these photos, he said the rear main seal was hardened but there was a leak in the lower part of the seal carrier (where the orange smile shaped plastic that is fitted with black silastik sealant). He replaced that too.
