Quick question after brief info here:

I have a 64 Dart (225) with 68,000 on it. In December, I got new points, carb rebuild, vacuum leak sealed, and replaced the radiator. Everything ran perfectly. Had to leave town for a long time. Just returned to it a few days ago (about 5 months later). I'd changed the oil at 67,500, so it only had 500 miles on that change, though 5 months of sitting. Started driving on the highway a few days ago and realized I was having electrical problems. Was driving through a really bad storm on the highway (inches of rain on the road), and after I came through the storm, my oil light came on. I instantly hit neutral, shut the engine down, and coasted over onto the shoulder. Checked the oil level, and it was full. Thinking maybe the sending unit just got too wet or shorted, I tried to start back up to recheck. No power. Long-story short, ended up getting someone to bring me an alternator, which fixed the electrical issues. So I started back up (though it took a while due to either a flooded engine or other carburetor issues), and sat and revved for a while. Engine sounded exactly right (no knocks, bumps, anything), but oil light stayed on. I was in the middle of nowhere, so I had no good option but to trust the oil level and the feel and sound of the engine (this is where I show my stupidity). Drove 4 hours with the oil light on, and the engine never missed a beat. Since then, I've had to drive around town a little bit, and the engine seems to be running a bit weaker than usual, though nothing too drastic.

So, my question: What might be causing the oil light to come on? Could it just be a faulty sending unit? Something in the oil? Could the massive rain have leaked in somewhere? Can the oil pump be faulty but still work well enough to keep it running for 4 hours on the highway and then some? Should I not start the car until I figure this out? Perhaps the oil just needs changing?

I'd be grateful for any suggestions or ideas.

Many thanks,
Jeremy

Get a mechanical oil pressure gauge and see what the oil pressure is. The light comes on at a very low pressure reading, something like 5 - 7 psi - I don't remeber the exact number. I'm pretty confident that if your oil pressure was really that low you would not have lasted 4 hours driving it. I'm betting that something is malfunctiong in the switch (sender) or warning light circuit.

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David Kight
'62 Valiant Signet, White
'98 Dodge Dakota
'06 Jeep Liberty

Growing older is unavoidable but growing up is strictly optional.

Could be as simple as the oil pressure sending unit wire grounding out somewhere along its length, or a faulty sending unit. I agree, if the oil pressure were genuinely low, the engine would not sound/feel normal and it wouldn't have lasted four hours plus.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

make sure your connection is good to the sending unit--- crusty sometmes does provide a good contact

You should look down the side of the engine and make sure the wire is actually hooked to the prong on the oil sender like Dan said. I had one kid that had the same problem, and found that the wire was unhooked from the sender and stuck/grounded to the block...rehooked it back up and the light worked normally ever since.

If you decide to do some replumbing, you can do a search on here (someone has a picture), and plumbing a "tee" into the pump and having the idiot light and a pressure gauge is not unreasonable.


-D.Idiot

There is also a combo gauge/light sender unit that can be installed, though I'll have to dig up the P/N.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Ooooh, Dan, I'd like that part number, too, if you can find it.

VM

thanks, guys. the wire from the sending unit is indeed attached; i even cleaned it off before reattaching. perhaps after i change the oil i'll take a mechanical reading and go from there.

I don't know why, but some years ago I had a run of oil pressure switches go bad on my /6. They would start to slowly leak inside and the light would come on.

I swapped the switch using the special socket w/o trouble and the light went out, but every 1-2 years the switch would go. Sorry, I can't remember the brand. It may have been a problem with the switches themselves or some vibration cause; I haven't had the same problem with any other engine.

Years ago Direct Connection used to sell a low oil pressure cutoff switch, which would kill the ignition the moment oil pressure fell below 7 PSI, IIRC.

Do they still sell such a thing?

Seems like I've seen a number of folks on this board who could have benefitted from such a device when they had an oiling system failure.

-Mac

Isn't that kinda dangerous killing the engine like that? I don't have power anything on my truck. But wouldn't suddenly killing power make for a dangerous driving condition? I'd much rather blow up my engine than get slammed in a car accident.

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The Old Goat '83 D150 225-2

AKA Ice Titan

Yes, absolutely right, these low-pressure ignition cutouts are not safe to use on the street, they are definitely a drag-race-only piece.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.