Random no start?!

[e30onBBSs]

I solved the last problem about 2 weeks ago maybe even less and I was driving in my neighborhood going up a hill and all of a sudden it stopped working. The oil Pressure light has been on forever and I think it has something to do with that, but it doesn't seem like anything is wrong oil system wise I thought maybe there is low oil, went and got some, checked the dipstick, it's okay. Poured in some anyways, still doesn't start. In a rage fit because I had no idea about what it could be I ripped the wire off the oil pressure sender because I thought it would still start without a possibly iffy signal. It still doesn't start. I also poured 2 gallons of gas in it to make sure it had gas. I'm going to do the normal diagnoses but I have some questions (again)

1. Could an adequate amount of oil but low oil pressure sieze an engine?

2. Will the engine not start without a signal from the oil pressure light? I read on bimmerforums it will still start if there is no signal.

3. The engine won't crank if the CPS is broken right?

4. Could this be the bearings? I don't really know what they are, what are they?

5. Could it be an oil pump at about 180k on the clock?

6. Can I get an oil pressure reading if the engine won't start with a gauge threaded into the sensor port?

Thank you all for all the help you've given me with this car, and for any answers you may have.

Ben

[spdracrm3]

I solved the last problem about 2 weeks ago maybe even less and I was driving in my neighborhood going up a hill and all of a sudden it stopped working. The oil Pressure light has been on forever and I think it has something to do with that, but it doesn't seem like anything is wrong oil system wise I thought maybe there is low oil, went and got some, checked the dipstick, it's okay. Poured in some anyways(not a good idea to overfill the crankcase with to much oil), still doesn't start. In a rage fit because I had no idea about what it could be I ripped the wire off the oil pressure sender because I thought it would still start without a possibly iffy signal. It still doesn't start. I also poured 2 gallons of gas in it to make sure it had gas. I'm going to do the normal diagnoses but I have some questions (again) do you have fuel delivery/pressure? how about spark at plugs?

1. Could an adequate amount of oil but low oil pressure sieze an engine?
yes ,it can have good oil level ,but if pump isnt creating pressure (ie pumping oil ) engine will eventually sieze
2. Will the engine not start without a signal from the oil pressure light? I read on bimmerforums it will still start if there is no signal. yes ,oil pressure light has nothing to do with engine starting or not

3. The engine won't crank if the CPS is broken right? engine will crank (turn over with starter motor) but wont start/run without correct signal from CPS

4. Could this be the bearings? I don't really know what they are, what are they? only if engine is seized up ,engine bearing are a soft babbet shell that supports the crank and connecting rods lubricated by pressurized engine oil acting as a fluid film bearing

5. Could it be an oil pump at about 180k on the clock? pumps do fail ,not often and when they do the engine usually starts knocking and will eventually seize , again this wont cause a no start unless engine is seized already and wont crank over

6. Can I get an oil pressure reading if the engine won't start with a gauge threaded into the sensor port? unlikely ,usually takes engine turning over 500 rpm to get a reading on a mechanical oil pressure gauge (you might see very slight needle fluctuation during cranking ,pressure will only be about 5psi till it fires and spins above 500rpm)

Thank you all for all the help you've given me with this car, and for any answers you may have.

Ben

[e30onBBSs]

Thanks so much for the info. That was really pro how you changed colors! It's not siezed because it cranks, I hope it's jus the cps

[e30onBBSs]

Random no start?!

It's the CPS. The longer I thought about it the more it made sense so I went out there in the dark and immediately saw what happened. It got caught in something, and is toast. I have to be more careful putting it in next time.

[spdracrm3]

nice find (as you went up the hill crankshaft shifted rearward ,there is about .006-.008 endfloat ,and it shorted out the cps causing stall),i bet your oil light being on is related also as that wire runs thru the same location as the CPS wire and was probably damaged and shorting out too (wire grounding will turn lamp on). make sure the plastic rails and clip are all good/present to hold those wires to front cover area so this doesn't happen again.

and drain that extra oil out....

[e30onBBSs]

nice find (as you went up the hill crankshaft shifted rearward ,there is about .006-.008 endfloat ,and it shorted out the cps causing stall),i bet your oil light being on is related also as that wire runs thru the same location as the CPS wire and was probably damaged and shorting out too (wire grounding will turn lamp on). make sure the plastic rails and clip are all good/present to hold those wires to front cover area so this doesn't happen again.

and drain that extra oil out....

Will do. Thanks Spdracrm! I think I'm going to give my hand at installing an aftermarket oil pressure gauge for fun and some wiring abilities 😃