GTSBoy

It's not an oil problem. It is yet another BMW design problem. Best fixed by not buying that Eurotrash in the first place, along with VAG products and half of Satan's limo supplier's catalogue.

If it is the HICAS that is loose, then it will be the outer ball joints on the tie rods, not the tie rods themselves that need to be replaced. If I was having to do that job, I would be doing the next logical step and binning the entire HICAS shitstorm, which banishes those stupid ball joints and all the rest of the stupid HICAS along with it.

Oxidation <> conductive.

It'll oxidise like a mofo and probably not do anything. But it won't melt.

Take it from an engineer. You could use 20-60 and not notice any difference. They all thin down to approximately the same viscosity at operating temperature. Look here: The viscosity axis is a log scale, so you have to keep in mind that every major division up that scale is 10x the value of the previous division. And that shows that at the 0°C end of the scale the difference in viscosity between 10 and 50 SAE oil is about that factor of 10. At the 100°C end of the scale, the difference is much less, about half an order of magnitude, which is about 3x (rather than 10x). Meaning, as oils get hotter, their viscosity converges towards a common (smaller) value. This is a chart for single grade oils, not multigrade. Keep that in mind, we're only talking about the behaviour of a single grade oil across the temperature range, and the difference in behaviour of a single grade oils at the same temperature here. I will address the multigrade situation after. There is no line there for 5 or 0 SAE oils, but you can imagine that they are a similar space below the 10 SAE line as the the 10 is below the 20. Look at the 10 SAE line at say, 10°C and at 90°C, being the typical (worst case) difference between a cold start and operating temperature in most of Australia. Some places never go below 20, some are frequently down to 0°C, but the argument is no invalidated by those additions to the limits I'm using. The viscosity at 10°C is about 0.2 Pa.s (Pascal seconds, which is the common term for the expanded SI units shown on the chart). At 90°C, it is about 0.009. That's more than an order of magnitude difference. Do the same for the 50 SAE oil and you get about 2 and about 0.03. That's more like 2 orders of magnitude. But importantly, the viscosity of the 50 SAE oil at 90°C is still about one order of magnitude lower than the 10 SAE oil at 10°C. This means..... A light weight oil, like a 0, 5 or 10, is quite thin at cold conditions, but is still thicker than a heavy oil is when that heavy oil is hot. And the engine is definitely going to be happy with the thicker oil at that hot condition, so it can only remain happy with the thinner oil at the cold condition. The difference between a 0 and a 10 SAE oil at typical Aussie cold conditions no worse than the difference between the thin and thick oils between cold and hot. And in fact, much less than "no worse". As has been said above, the only reason maufacturers are speccing thinner oils for modern engines is to reduce fuel consumption and emissions. Thinner oils do pump faster at the first turn of the engine and so do provide earlier rise of oil pressure and supply of oil to rubbing surfaces (like cams). But really, for actual protection against these initial rotation conditions, we actually rely more on the retained oil which is kept there by the film strength (and by modifier packages that are added to the oil) anyway, and thicker oils are better at hanging on anyway, so it is probably a moot point. If I had an engine that demanded 0W-20 oil, I would have no issue running 10W-40 in it. The chart below is for multigrade oils (which adds confusion to the explanation, which is why I used one for single grade oils above). The multigrade oils have a difference viscosity curve, because they act like a thinner oil at low temps and as a thicker oil at high temps, so the scale gets compressed. You can see that the scale on the below chart is not logarithmic (is linear), and that all the oils collapse to the 10-25 cSt range when at operating temperature, and are much more viscous at 10°C (which is not shown on the chart, but you can see they would all shoot up above 100 cSt.

And that would be wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong wrong

This is me....for the last year or so.

The answer to both questions in the title is "yes".

Were those all there and working properly prior to the heat hose surgery?

Hmm. If it was S1, I would have suggested that you might have upset the coil igniter by working at that end of the engine. As is it, I would suggest that you might have upset the coil loom. You might have tired old wiring connectors that got moved. Not particularly likely though.

So, what you're really saying is that you should have bought an IC7 to put there?

A helical is not the best choice for a track diff, particularly if there is going to be inside wheel lift (simply from high G cornering and high roll stiffness, or from hitting kerbs). This is because a helical acts like an open diff when when one wheel is unloaded.

S1 or S2?

If it's in good shape, sure.

Is the suspension at full droop? Try pushing up the lower arm with a jack. Careful not to lift the car off the chassis stands.

Point 1. If you want to do this and want to use that engine, just buy the whole Stagea. You will hate yourself less by getting everything on it all at once and then having to dispose of the stuff you don't want, compared to how much you will hate yourself if you miss buying something and it isn't there when you need it. If you can't afford to buy the whole wreck, then you can't afford to do the swap anyway. 1996 Stagea does NOT have a Neo. It is a version of the vanilla RB25. There is a bit of a halfway-house RB25 that was in Stageas at that time that kinda look like a Neo, in that they look like they have some Neo looking parts on them. But they are not Neo. They have hydraulic lifters and the same old bottom end as the vanilla 25. So, technically, putting that engine and its ECU into an R34 might be challenging. There might be some shenanigans with ABS communication, for example. I'm only guessing, because I've never contemplated messing around with stuff from that era. Sadly, you probably cannot Nistune the ECU (I haven't checked, but R33 era RB25s don't have a Nistune option because they have a stupid orphan ECU). So you will possibly end up contemplating an aftermarket ECU to get it working. You will DEFINiTELY want to take the Stagea's auto trans. The one in your car will die in very short order, especially if you turn the boost up at all. This is true even if you add a turbo to your existing stuff. Hence why I suggest buying the whole wreck.

Boot lip or tail lights.

That's not a thing. Makes perfect sense. The Quaife is a helical diff. A totally different operating principle, in no way similar to a clutch diff. Helicals are the most polite street LSD possible.

You didn't have "no luck". No-one is going to be able to identify the very random problem that you have. You are going to have to do actual diagnostic work. Put a go pro under it and go for a drive. Run it on the dyno. Tape a microphone under the car in various locations until you get an increase in volume. Etc.

good

Why not look to see if the wiring is intact before lurching into swaptronics?

Make a tool out of shim (ie coke can thickness stainless steel) like a little crows-foot spanner than you can slip under the head of the screw and pull upwards (away from the surface it is screwed to) while you turn it with the screwdriver. You'll be trying to get the threads to engage with an edge of something in the hole to provide some drive out.

Solenoid valves are just a coil of wire wrapped around a movable iron core. Put the required volts onto it and the wire creates a magnetic field that makes the iron core move. The moving iron core forces the valve to either open or close (depending on whether it is a normally open or normally closed valve). NO valves are closed by powering them. NC valves are opened by powering them. The failsafe valve is NO and is closed when powered. You should feel it click when it changes state from on to off or vice versa.

Is the failsafe solenoid even opening/closing when you power/depower it?

Well, it has to be. Yes, and, they are saying "This failsafe must be disabled" (My emphasis). And they are saying exactly how to do that.... "Giving the failsafe a switched +12V constant signal will keep the solenoid closed/disabled". I interpret that to mean that "any time the car is running, you want 12V permanently on the solenoid". Ie, power it to close it when the car is running. Have the power switched off when the car is not running.