92' Z32 OIL Pressure/Smell Issue and Alt/Battery Died.

[bgtoronto]

Hey all, was hoping someone out there could shed some light on this annoying issue I ran into yesterday. On my drive home, I noticed a faint smell of burnt oil coming from...well...somewhere. Minutes later while driving at highway speed, I noticed my oil pressure gauge starting to drop quickly...I would try to kick it a bit when it got dangerously low and it would jump around a lot but never went to 0. I should mention that I had the pressure sensor replaced about 3000kms ago and it's been perfect since. Once I got home, I let it cool down then started it, let it warm, and would rev looking for pressure drops...it would slowly drop if i held it between 2-3k rpms..but anything below or above that it would appear normal.

This morning, it is dead. No alarm, no power, no nothing. I had suspected when I had the oil sensor replaced that my alternator was dying, and asked them to test it which they said had passed. I'm clearly not a mechanic but am I safe to assume that all of the above was caused by a bad battery or a bad alternator? I know these can cause oil pressure issues and issues with all of the gauges but I'm still trying to figure out why I smelt oil before noticing anything else if this was the issue...maybe over compensating?!

Any light on this would be great, my cars sitting dead while I try to figure out the most efficient way to tackle this :P

Thanks everyone!

[ThisIsSparTTa]

Oil sender reading is a resistance reading, so if you're not supplying the right amount of power, it would make sense to be off. When my alternator died, first just the brake light then all the lights would come on, especially during braking. It didn't last long from there.

For the oil smell, you're just going to have to look around under the engine and under the car. Make sure your dip stick didn't get blown off.

Measure voltage across your battery. Assuming its low then most likely your alternator died and drained the battery based on the other behavior. You can always have your alternator tested at the auto store before buying a new one if you remove it.

One other idea for the "oil" smell that would go with the alternator is if your power steering J-Hose or high pressure line is leaking, they will s*** all over the alternator and kill it, and the ATF will move backwards getting on headers, turbos, exhaust, etc. Check around your power steering pump for extra "oil". If its red, its ATF, and then you'll need to find which hose is leaking.

[bgtoronto]

Thanks a ton for the reply, dip stick stayed in, and I couldn't find anything leaking in the bay or under the car after sitting. My mechanic thinks my alternator shorted out and I smelt it burning, and then shortly after experienced the driving effects. I have noticed changes in the power steering lately however..sometimes becoming a lot tighter than others, so I'm afraid you may be right about the J-Hose or pressure line...I'll have to search a bit more for fluid, but I guess if the alternator died than the power steering would be affected.

The car has 68000km on it and has been great until now. (Oh, and when my recalled PTU died suddenly, shutting it down on a highway)

[ThisIsSparTTa]

Power steering is mostly a "dumb" system, there's not much electrical to it except for a couple of sensors and fail-safe cutoff. The PS pump pressurizes the fluid, the rack uses that to make steering easier, and returns the fluid to the reservoir to be sucked in by the pump again.

However, if you were leaking PS fluid, and it couldn't build that pressure, that would be a problem.

You'll have a good idea when you go to pull the alternator if its covered in an oily substance.