I know of no oil pressure spec.
Personal preference.....idle 10PSI or better, higher revs 45PSI+ with hot oil.
Low pressures are likely a sign of plain bearing wear, most noticeable with high pressures when oil cold since it flows out of bearings but lower pressures when oil is hot.

I also prefer getting oil pressure from the far end of the oiling system so you know earlier on is good. But that's me.
Oil pressure lights (all warning lights I call "idiot lights") come on too low, you should never see them except a flicker when first starting.

 

you should never see them except a flicker when first starting.

Yup. In my case it's only on before a cold start, so I know it's still working. The moment the oil pump starts moving it goes out, so I know the engine is healthy.

The noise I'm hearing is most likely a mildly gunked HLA.

 

I don't know of any oil pressure specifications either. All I know Is that when the light comes on it's too late lol.

 

Man I am glad you started this thread, I was considering doing the same just recently. I also have a cheap oil pressure gauge. I was a little suspicious of its readings eventually, so I bought a Glowshift one and put them side-by-side. The difference in readings is astronomical. According to my cheap gauge my engine is failing, often reading as low as 0.5 or even 0.3 bar (does that seem right to you?) Meanwhile, my GS says 17psi which as far as I understand is where it is supposed to be at idle fully warmed up with 5W30.

What's really messed up about this is my cheap gauge wasn't this way initially. It would fairly consistently be at 1.1 bar at idle, and sometimes go to 0.9 bar when things were more hot. Made sense to me, the engine I have in my car isn't in the greatest condition either (a temporary solution until I rebuild one of my old engines).

 

Some updates to add:

I've been giving thought as to why a cheap gauge may read incorrectly, and I get the feeling that it is related to temperature. Assuming the sensor is on an oil filter sandwich plate then it is fairly close to bank 2's header. I planned on creating a heat shield nearby to see if that would yield different results, but I get the feeling it's possible the sensor may have been damaged from heat exposure already (which may be independent of the header as well). I suspect that Glowshift's sensor is probably better heat-resistant (rightfully so).

As far as oil pressure itself goes, I recently came across a rule of thumb stating that the minimum oil pressure for most engines (so basically outside of dedicated racing applications) is 7PSI per 1000RPM. Which would be a good peace of mind if true.

 

Your rule of thumb sounds a little low to me, especially once the oil is hot. It's a start though.

 

Hmm, my gauge goes down to about 0.4 bar with hot oil, but the genie lamp isn't lit, so I guess it's okay.

 

jeez that's right on the edge of spec, which is 7.3psi or 50kPa (or .5 BAR).

 

Well.. either that or I'll start seeing the gentle flicker of Aladdin's Lamp on the dash and then I'll know it's time for a set of new bearings.

 

Well... Something might NOT be fine. I just dropped the oil, under 2000 km on it, and it is very sparkly. Hardly anything will stick to a magnet, but it looks like a lot of fine aluminum has been circulating around in the engine. Replacing oil and filter now but I might need to do another quick oil change in another 2000 km.. or find another motor. This one has likely had it.

 

Damn. I hope it's just from the cam timing chains digging into the heads/covers.

 

Ooh yeah, got a video.



That oil has less than 2000 km/1200 miles on it.
Engine was filled with 5W-30. Refilled engine with 5W-40 to see what happens. With 5W-30 there would be a very soft tapping sound audible in the cabin at low rev - not really at idle, but at low revs, which would get drowned out at about 2500 RPM. Now with 5W-40 the engine was initially a lot quieter, until the oil started to warm up and the tapping started, a little louder this time, and as I dropped off my garage buddy we noticed that there's now an additional sound which sounds like a chain chafing.

All noises are still at camshaft speed, so it's hopefully a head issue (but it could also be early stages of piston slap or rod knock).
Also, in my other thread I was wondering if I should be worried to see glitter in the PCV catch can.. well, there was more glitter in the catch can. And plenty in the oil, along with flakes of something.

I've got fresh chains, so I might try swapping those in once buddy's Mk2 Probe is out of the garage.. until then I don't think I wanna keep working on this one too much. Might need to buy another Tiburon, as that's still the cheapest way of getting a replacement motor.

 

I've seen a few situations where glitter appears lately. Non Ferrous is typically light rod bearing wear. Ferrous is typically heavily worn thrust bearing, HLA/lifter/cam wear or old cam chains striking the bare metal of the wear indicators. If you replaced only the wear indicators and not the chains, that's usually going to wear down to bare metal rapidly. We don't have chain guides as people tend to name them. They are wear indicators to warn you if chains are stretching. Brand new chains won't make contact with these parts until they stretch excessively from age or abuse.