low oil pressure (light)

[RamenPride]

Brief background: BSE kit from ExtremePSI w/front bearings flipped. Lightly ported oil filter housing. Oil port mod done to the cylinder head. Small 16G fed from the head using a stock 1G line. Reconditioned/re-sized rods (ARP rod bolts), rod bearing clearances in spec (don't remember exactly what they were, maybe .002?). Cylinders honed, new NPR pistons and rings (which is why I'm using dino oil for the time being). I used Castrol Syntec 10W-40 before all of this and the low oil pressure idiot light never came on.

I've had two incidents of the low oil pressure light flickering at idle since I started driving the car again. The first time happened with Super Tech 10W-30 dino oil and Purolator 14610 filter. I dumped it out and re-filled it with Super Tech 10W-40 dino oil, but had it happen again yesterday. Interestingly enough, the temperature was above 70 both times it happened. If I blipped he throttle, the light went off but flickered at idle again. When the light came on, I didn't hear any knocking or collapsing lifters. When it's cold out, the light has never come on. The light coming on worries me, but at the same time it doesn't because I have an Autometer electrical oil pressure gauge (remote mounted sender) that shows the oil pressure at about 12 psi at idle (it's a tad below the line between 0 and 25). I know the stock gauge isn't very accurate, but at idle it's nowhere close to the bottom mark either. Once warmed up it's about 35psi at 2000rpm crusing on the street, maybe 50-60psi on the highway cruising at 65mph in 5th. The wire is still clipped to the idiot light sender, but has anyone ever had one of these go bad? Should I be genuinely concerned about the light, or just ignore it because everything else says the oil pressure is fine? Coolant temp is fine, both by the stock gauge and Autometer electrical water temp gauge.

 

[tmoney20g]

Sounds like the sender for that is bad, I plan on removing mine, and the bulb in the cluster that goes with it. And I'll keep the factory needle gauge, and I'm going to add the innovate MTX-D (oil pressure/temp) gauge to the car. With that gauge, I can set a warning that will flash the gauge, so I won't need the idiot light, or its sender/wiring at all.

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[AllanL]

disconnect the wire for the oil pressure idiot light and connect to ground.

oil light on gauge should turn on.

if turns on, replace oil pressure switch.

if not, bulb or wiring.

 

[92AWDHX40]

I like that tony Im going to get rid of my prosport gauge soon, I like that link, to the innovate thanks.

 

[RamenPride]

I replaced the idiot light sender with one from O'Reilly's and the same thing happened. I drove around for a bit after work, and the light came on when the idle got kind of rough when the fans kicked on (idle dropped below 700rpm. All the lights were on also). However, as usual, the gauges read ok. I stepped on the gas and held it open at 900-1krpm to keep the light from coming on while waiting at the stoplights. I got home and parked it (light wasn't on), and let it run for a few minutes. The light never came on. So, the whole thing seems related to the idle (and maybe a dying alternator as well).

 

[oneslowwdsm]

Just a random thought, probably not your issue but could be somebody elses. I had an intercooler pipe just barely touching the sender, triggering the light randomly. Took me a bit to figure it out, should be obvious but sometimes you don't think

 

[1995-tsi-awd]

I went to heavier oil, but still had the issue when I would slow down a make a turn. BISS needing adjusting and it hasn't done it since.

 

[RamenPride]

Luckily, the light hasn't come on since I last posted. It was probably related to the idle dropping, since the idle's smoothed out and more consistent since I've been driving it (finally put 350 miles on it after the car sat for years). Still has me worried every time I drive the car, though. Good thing I have another vehicle to drive to give me a break from the stress of this car