I've been trying to track down the source, but haven't come across it yet.

When I drive more than about 2km, I can detect a mild scent of oil burning, like it's leaking onto the exhaust manifold somewhere, or cooking off of the block.

The front exhaust area is clean, no signs of oil leakage at all, so I am thinking it's going to either be on the rear bank, or in the center of the block.

Are there any known gasket or seal issues that would cause the slow leak? I'm not seeing any signs of exhaust gas in the coolant system. No over pressurization, no foaming, no fuel smell in the radiator, and coolant temps are staying steady where they should be, so I doubt it's a blown head gasket. I will be flushing the coolant out and replacing it to double check though.

I am waiting for a cannister purge valve to come in, and had a thought. Is there a PCV valve on the rear bank that could be broken? I know on the cars I am used to (older engines, pre 1980 US model stuff), if the PCV valve was messed up, it could be letting oil out through the grommet to get that lovely smell going.

The one and only PCV valve is on the driver's side of the front bank rocker cover, you can't miss it.
Pretty much no chance that is the cause of your problem.
Most likely explanation is the rear rocker cover seal on the firewall side leaking a bit of oil,
After about 120,000 k the rocker cover gaskets can go hard/brittle and start to leak oil, mine did.
Easy enough DIY job to replace, get the full kit of front and rear gaskets plus plug tube seals from Mal for not many $.

Most likely explanation is the rear rocker cover seal on the firewall side leaking a bit of oil,
After about 120,000 k the rocker cover gaskets can go hard/brittle and start to leak oil.


+1

2Km is about right to get the exhaust hot enough to go smelly.
Same engine design as the Magna, rear rocker cover gasket leaks any time after 100,000 km, and the oil from the rear runs straight onto the exhaust pipe. Front will leak at the same time, but doesn't seem to make as much of a smell.

Even if you do get the rear rocker gasket changed, the smell will linger for a while. Helps to spray degreaser onto the COLD exhaust from behind the rear bank or underneath, and wash with a hose.

It will be the rear bank rocker cover gasket.

Spiffy, that's pretty much what I was suspecting anyways. Same issue my 3000GT had with the 6G72 engine. What I am guessing is that that particular area holds heat a little too well, so that gasket cooks off faster than the front one, which has the blow-by from the radiator fans going on it.

Who's Mal? Mits-Fix?

Yep, Mal = Madmagna = Mits-Fix.

Now time for another stupid question. I've looked at the engine, and I'll have to take the inlet manifold off. I can't seem to find a gasket for it by searching online. Would one designed for a 6G74 fit it, or no?

Now time for another stupid question. I've looked at the engine, and I'll have to take the inlet manifold off. I can't seem to find a gasket for it by searching online. Would one designed for a 6G74 fit it, or no?

No need for a new gasket unless you somehow damage the existing one, it's metal and re-usable.
Even if you need a new one they are fairly cheap from your local stealership.
(and yes, I think a 6G74 gasket is the same, but don't quote me on that!)

Yea, knowing my luck, I probably will since I'll be doing the work up in Saddleworth, far far away from anywhere I can get a new gasket.

Hopefully I won't though, that'd piss me off.

Well, just got done spending all day Saturday working on the car.

The rear gasket was most definitely leaking...but even after over 100km, I can still smell it cooking oil somewhere. I'm guessing it'll need to go on a lift to see if I can find the leak.

Either you didn't clean off all the spilled oil, or you may have overtightened the rocker cover and caused the new gasket to leak.

The torque setting for these bolts is very low 3.5 NM if you over tighten them they will leak.

On the Magna, the rear cover leaks oil straight onto an expansion joint in the exhaust system. Seeing this is made of woven steel wire, it holds a lot of oil that is impossible to clean completely, and takes a long time to smoke the oil off. Perhaps the 380 has the same setup?

I've found an LED torch shows up the blue oil smoke really well. Need to do this at night, away from other lights. With the engine hot and the smoke smell present of course.

I'll try tonight with the LED torch. It's quite possible that it's in the flex joint, so I will take that into consideration. I didn't even think of it getting into there when I was poking around as I took everything apart.

As for the gaskets, I made quite sure to not overtighten them, I'm used to the low torque specs from my GTO and Lancer I had before in the US. (I'm also glad that my FIL had a torque wrench that went that low)

I think for right now, I will simply wait and see how it goes throughout this oil change. If I still can smell it when it's due for another, I'll find a way to get it up on a lift and do a full inspection. I just got rather twitchy with it because this is a very recent purchase, and I can't afford to do any major work to it right now if it is something big.

I'll try tonight with the LED torch. It's quite possible that it's in the flex joint, so I will take that into consideration. I didn't even think of it getting into there when I was poking around as I took everything apart.

As for the gaskets, I made quite sure to not overtighten them, I'm used to the low torque specs from my GTO and Lancer I had before in the US. (I'm also glad that my FIL had a torque wrench that went that low)

I think for right now, I will simply wait and see how it goes throughout this oil change. If I still can smell it when it's due for another, I'll find a way to get it up on a lift and do a full inspection. I just got rather twitchy with it because this is a very recent purchase, and I can't afford to do any major work to it right now if it is something big.

Not uncommon for a second hand car to present you with a few problems.
Leaking rocker cover gaskets, oil in the spark plug tubes, and cam belts way past replacement time are a few common ones.

Lack of servicing by a previous owner is not covered by any dealer warranty, though, AFAIK.

I found that when I replaced the rocker cover gaskets and plug tube seals on my 380, the rocker cover bolts felt a little loose after about a week, or around 200 km.
No oil leak that I could see or smell or feel, but I gave them a little tweak anyway (I went by feel rather than using a torque wrench), and never had a problem afterwards.

Oh, I well knew I would find a few things needing fixing with the car considering the KM's it's done. I didn't smell any oil when I took it for a drive to the servo to get some drinks (about 4km) though I'll be doing a run to the airport to pick up a friend on Wed, so that will be the test point I think. The spark plug tubes were all nice and clean, each one got carefully examined when I took the covers off. LED light inspection then wipe the walls with a cloth covered probe.

Overall though, I still think I've gotten a good deal for what I've paid and put into it.

Timing belt looks great still, it's got 10k before it's due according to the service sticker on the bonnet, that was really the only concern I had when I bought it. Everything else I can deal with easily enough.

Only thing left that I feel needs taking care of is flushing the transmission. I got all excited because Supercheap has a canister filter that's tagged on the box for the 380. When I changed the oil and then went after the transmission fluid, I got a rather rude awakening. So now I have to wait for when I am working and can afford a third jug of fluid @$60, and paying a shop to flush it for me since I don't have access to the machine to do it.

Distributor oil ring may be the culprit.

It was the rocker cover gaskets. The shop I took it to did a full inspection. Apparently I actually didn't have them tight enough, even when I did the Permatex on them.

Also found out that the pre-tension was completely shot, and that whomever did the water pump before did a completely shit job.

Good news is, the car is back in my carport, and running great.

excellent outcome

I agree, though I do find it a little odd that the rear cover required a fair bit more tightening than is normally called for. Eh, so long as everything's running right for now.

Once all of the parts come in, I will be doing a fun little project on the car.

I'm going to take the plastic surround for the MFD enabled models, and building a custom phone mount there (instead of the computer). The end result will be that I dock my phone there (with a hardwired charger running off of the car's wiring harness) to use it as a GPS. Total parts cost is about $70, and I'll need to buy a radio pocket for scrap plastic to trim and fill the hole. So, for under a hundred bucks, I have a secure place for my phone, GPS capability, and I don't ever have to worry about the device breaking or needing replacement.

For anyone interested, I'll take pictures of the process and do a walk-through.

Distributor oil ring may be the culprit.
not on a 380

Well if the oil smell stopped eventually - and you used a torque wrench - Id imagine the covers were done correctly by you. It just takes a few hundred Km for the smell to go away.

If the shop you went to just "nipped them up" by hand without a torque wrench, they would have felt "loose" becaus the torque spec is so low... And they may have bent your covers in the process.

I think you fixed it correctly, now they may have damaged it.

No, even after I did it, I was seeing obvious spotting underneath the car from excess oil.

And the shop did use a torque wrench, along with cleaning both surfaces thoroughly, inspecting the covers for warpage. The guy that did the work said that I had them done right, and he couldn't find any reason why what I had done was still allowing oil to work. Best we figured was that I crinkled the gasket or something when getting the rear cover on.

The main thing is that now the car's running the way it should, no problems...I just can't afford to renew the rego on it. (Yay for job hunting?)