Low Oil Pressure light came on in a 1994 Honda Accord

[lube_n00b]

So I started up the accord this afternoon, drove it for maybe 7 minutes and the oil pressure light started to blink. The car never reached midpoint on the coolant temp gauge(I'm in texas). So I didn't drive it further than maybe a few miles. I was about to turn to get out of neighborhood and I saw the oil light blinking. Immediately stopped, hazards, turned engine off, popped hood and checked the oil(5w-30 full syn). Full of oil.

I'm hoping this is just a bad sender unit as the car is really old.

I decided to take my chances and turn the engine back on, the oil light didn't come back on. No knocking, tapping, or anything out of the ordinary, just a healthy sounding engine. I decided to limp it back home at about 1k rpm. So about 7 minutes home as well. I almost contemplated pushing it but decided not to as the engine sounded healthy enough to make it back.

Any ideas on what actions to take here? I definitely don't want a blown engine, but if it's time to pull it and go for a rebuild, so be it.

 

[michaelluscher]

We need more specifics
Year/engine/mileage?

Recent OCI? Recent major engine service?

 

[dogememe]

Try just replacing the sensor. If it still happens, use a mechanical pressure gauge/tester to see if the engine is done.

 

[lube_n00b]

We need more specifics
Year/engine/mileage?

Recent OCI? Recent major engine service?

1994 Honda Accord LX/ F22B2 SOHC non-VTEC/ 297k

Engine Services performed:
- Front seals replaced
- Timing belt replaced
- Cooling system overhaul(hoses, thermostat, water pump)
- Oil Change (Pennzoil 5w-30 Full Syn Platinum w/ Honda OE filter)
- General tune up(spark plugs, wires, distributor cap, rotor, igniter)
- Valve clearance check and adjustment

These engine services were all performed about 1k miles ago.


The oil pan was replaced, but this was prior to me buying it.

 

[JohnnyG]

Maybe the wire from the sending unit fell off.

 

[kschachn]

Maybe the wire from the sending unit fell off.

Yep lots of possibilities here. The OP needs to track them down one by one, and ultimately make sure that the actual oil pressure is measured using a gauge.

 

[cptbarkey]

yep, visual inspection first, wiring harness where the sending unit is. could be burned etc. This video makes it look easy, its because he doesnt have an exhaust manifold on it.

 

[lube_n00b]

yep, visual inspection first, wiring harness where the sending unit is. could be burned etc. This video makes it look easy, its because he doesnt have an exhaust manifold on it.

So to test the oil pressure I need to get a gauge screwed into there. Might not be fun, but I'll crawl under and see if I can get grab an oil pressure gauge from harbor freight and get a reading. The minimum in my manual says 10psi at idle and 50psi at 3000rpm. I'm hoping the numbers are better than that.

If it's the sensor itself, I'll order an OEM sender since it's 35 bucks anyways.

 

[SHOZ]

So to test the oil pressure I need to get a gauge screwed into there. Might not be fun, but I'll crawl under and see if I can get grab an oil pressure gauge from harbor freight and get a reading. The minimum in my manual says 10psi at idle and 50psi at 3000rpm. I'm hoping the numbers are better than that.

If it's the sensor itself, I'll order an OEM sender since it's 35 bucks anyways.

More than likely it's not the sensor but if you screw anything in beware the thread pitch as it may be 1/8-28 BSPT vs 1/8-27 NTP. This is how my Hyundai is and most on the forums will just cram the NTP into the aluminum threads and call it a day.....until they need to take it out and reuse it.

 

[dishdude]

99% of the time this boils down to two things. Low oil level or worn main bearings.

 

[lube_n00b]

99% of the time this boils down to two things. Low oil level or worn main bearings.

Well the oil level is fine

 

[VTECOverRated]

Back in the day I remember this happened a lot on cars that got old. Kids would just crush the bulb and turn the light off that way lol.

 

[kschachn]

yep, visual inspection first, wiring harness where the sending unit is. could be burned etc. This video makes it look easy, its because he doesnt have an exhaust manifold on it.

It’s missing the intake plenum. The exhaust manifold is in the front.

Working at it from underneath is the only way you’ll reach it with the intake attached. And it’s not particularly easy if the car is not on a lift. It’s quite a reach.

 

[kschachn]

So to test the oil pressure I need to get a gauge screwed into there. Might not be fun, but I'll crawl under and see if I can get grab an oil pressure gauge from harbor freight and get a reading. The minimum in my manual says 10psi at idle and 50psi at 3000rpm. I'm hoping the numbers are better than that.

If it's the sensor itself, I'll order an OEM sender since it's 35 bucks anyways.

I’ve done this and let me tell you it’s not easy.

 

[lube_n00b]

I’ve done this and let me tell you it’s not easy.

Well. I'll try get this project done this weekend. I really don't have any other choice. I was going to rely on this car to get me to and from work next week since my daily has a seized brake caliper and parts don't come in till Monday.

I'll let you guys know how it goes.

 

[cptbarkey]

It’s missing the intake plenum. The exhaust manifold is in the front.

Working at it from underneath is the only way you’ll reach it with the intake attached. And it’s not particularly easy if the car is not on a lift. It’s quite a reach.

thanks, its been awhile, i recall other honda's being in the back of the engine. such a pain to change the oil filter.

 

[ripcord]

Check the wire to the sender for cracks in the insulation. The light will come on if the circuit is grounded, like when a wire is touching the body.

 

[lube_n00b]

thanks, its been awhile, i recall other honda's being in the back of the engine. such a pain to change the oil filter.

Looks like on this particular model I'll have to remove the filter as well.

 

[kschachn]

Looks like on this particular model I'll have to remove the filter as well.

It will be in the way, yes. For me the biggest problem was that I just couldn’t reach up that far while laying underneath the car.

 

[lube_n00b]

Going to follow this video.
Good information, very thorough diagnosis, and it'll be here for future reference if anyone runs into the same issue.