oil pressure light

[n2motorsports]

one problem after another.  got the e36 m42 into my e30 running and idling well but the oil pressure light is on.

so i when ahead and replaced the oil pressure switch and light is still on.  it drives well, and seems to be pushing lots of air out the oil filler cap when removed.  took my son to school ~ 20 miles and everything felt good.  let car cool down and oil level is perfect.

the mechanic that did most the swap had swapped over my oil pan and checked the oil pump bolts already so dropping the pan is probably isnt necessary.

after some reseach, could it be the oil passages are clogged?  the motor sat for 1-2 years prior.  maybe a can of seafoam will clear it up?

[Geoff]

I think I would probably try to get a reading with an analog guage to see whether the motor actually has oil pressure or not.   IF it has really low pressure, a 20 mile ride might cook it.  If you dont want to try that, you could pull the valve cover and idle the engine, if oil shoots everywhere low pressure is not likely.   Maybe wiring or maybe another issue keeps the light on
                                Geoff

[n2motorsports]

Finally picked up a gauge from harbor freight to test my oil pressure, will be doing that tomorrow morning.  

I'm pretty sure the light is working properly, I parked the car on a very steep hill facing downwards and the car started and idled for 5 mins without the light.  After moving it to level ground the light progressively got brighter.

On a side note, when my mechanic did the swap, he swapped the newer oil filter housing over with the plastic cap (should be fine??).  Also, suspecting the globs of blue sealant around the oil pan, I was horrorified when I pulled the filter to visibly see specks of sealant trapped in the filter.  This leads to me believe I've got a oil passage clog somewhere.

Guess I'll drop the pan again.  I'm confused, does that paper gasket need additional sealant?  I've used Hondabond in the past with good results, but talking to a parts guy, he advised to just go with the paper gasket.  Course he was a m20 guy and those gasket's are nice and thick.

[Wrench]

You might have a some chunks of silicone clogging the pickup screen on the oil pump. I've seen it happen on a few engines. If that oil pressure check with the gauge says it's low, I'd pull the pan and check it out.

[n2motorsports]

Thanks wrench.  Any idea if I go with silicone or just the paper gasket?

[Wrench]

Clean... clean.. clean surfaces, new gasket, very light coat of silicone sealant, tighten snug. Too much sealant will create a hydraulic effect and split the gasket. I learned that the hard way.

[n2motorsports]

Finally got to the oil pressure test:

PSI / RPM

27 /  1k  idle
53  /  2k
60  /  3k
64  /  4k

lowest it drop was after the 4k, it dropped to 25psi

Bentley manual says minimum idle is 7psi... seems low and elevated speeds for our cars is 63 psi +/- 3.  According to that looks like my oil pressure is good.

Time to drop the pan, will I be able to clean the oil screen when I remove the lower oil pan?

[Geoff]

yeah, removing the lower pan exposes the screen, as well as any pieces of timing componants that may have flown off..the oil pressure is good, have you figured out why the light stays on?
                                        Geoff

[n2motorsports]

still troubleshooting the light.  Bentley says when ignition is "ON" the oil light should light up, but it doesn't.  So I grounded the harness and it lit up...so harness to dash is good and that would mean the new switch is faulty.  I"ll buy another switch (oem this time, this one was a duralast from autozone) or get a cheap ohm reader to test continuity.  

Stupid red lights...  i just got the ylod aka red light of death on my ps3 too.

[n2motorsports]

so I've been putting off working on the car forever.

Geoff - i'm gonna pull the oil pan off to check, i don't know why i trusted the guy that installed the motor for me.  however, this is my question... when should you pull the upper oil pan?  would like to just pull the lower pan and check the bolts, if they have all fell off then i should probably remove the upper since the gasket may have slid out of place?

in short, when should you pull the upper oil pan?

[bmwman91]

How does your temp gauge behave? I have definitely mixed up the plugs for the oil pressure switch and temp sender before. It of course usually leads to the temp needle being buried in the red and the oil light slowly coming on. I'd imagine that you would be more concerned if the temp needle was showing max temp!

The M44 oil filter housing swap is no big deal. I have one on my M42 as well. Same pressure sender and oil passages and everything. If your pressure measurement was showing solid pressure, then I too would suspect an electrical issue. If the screen was clogged up, I think that you would in fact read low pressure since you are measuring it after the pump/screen. It does seem unlikely that a new sender would be faulty, but who knows. Have you pulled back the rubber boot on the plug and checked the wire condition? Sometimes the wire will fracture where it is crimped to the terminal.

[n2motorsports]

Yes the temp gauge is wacky and I've swapped both sensor harnesses..  Traced it back to a short in the black rectangular box underneath the throttle body.  Definitely some electrical gremlins but I still suspect some loose bolts in the pan because I hear a very distinct "air sucking" tap under the valve cover.  Leads me to believe oil pump maybe sucking air. 

[bmwman91]

Yeah, if the upper pan bolts came out, the gasket around the sump could have imploded and allow air into the pump.

[n2motorsports]

Today I dropped the oil pan.  Most of the bolts were snug except for the one in front of the oil pick up.  Apparently the mechanic over torqued the bolt and stripped it.  My ocd got the better of me and so I attempted to drop the upper pan to helicoil it but one of those torx bolt was stripped And sstopped me dead in my tracks.

Found some brown rubbery bits at the bottom of the screen as well.  Wonder where they came from?

https://www.dropbox.com/sc/siuw60c27jvb0ru/UwwmgTle52