Oil Light Came On

-
mydart270

mydart270

myDart270
Joined
Mar 18, 2014
Messages
190
Reaction score
7
Location
Brattleboro, VT
I have a 1968 Dodge Dart SL6 and been driving it for about a year. Last night the RED oil light came on at dash...scared me to death!!! I stopped, checked oil level, no oil on ground, no engine parts on ground, and said "Go or Blow". I restarted again, oil light is OUT and 5-mins latter RED oil light is ON.

Where can I start checking? I have a new cluster, will install this weekend. Engine rebuilt in 1995, no heavy duty driving, only to local car shows. Last night 1st time at 50 mph. Temp meter OK, engine runs smooth.

Pls help. Oil pump went bad? Bad gauge at cluster?

Thx everyone...great forum...great people!!

mydart270
Brattleboro, VT 05301
 
The first thing to do, is remove the oil pressure sending unit and attach a mechanical gauge to verify oil pressure loss. If the gauge shows no sign of pressure loss, than replace the sending unit.
 
70dustah said:
The first thing to do, is remove the oil pressure sending unit and attach a mechanical gauge to verify oil pressure loss. If the gauge shows no sign of pressure loss, than replace the sending unit.
Click to expand...


Ok....will test today. Off to NAPA to buy oil pressure tester. Will post my findings today.
 
mydart270 said:
Ok....will test today. Off to NAPA to buy oil pressure tester. Will post my findings today.
Click to expand...
If you want to own one than the cheapest way would be to drop by a Harbor Freight nearby, as it sounds like you probably wont need it much. Also most parts store have a free loan-a-tool program which sounds like your best avenue to take.
 
70dustah said:
If you want to own one than the cheapest way would be to drop by a Harbor Freight nearby, as it sounds like you probably wont need it much. Also most parts store have a free loan-a-tool program which sounds like your best avenue to take.
Click to expand...
Good call on the parts store loan a tool. I have seen it at auto zone.
 
Hopefully its just a faulty sending unit. Had the light pop on, on the turnpike one day. Did what you did, pulled over and checked everything. The motor was still quiet as a pin, so deep down I was hoping all was good. Turned out to be the sending unit. Waiting for your results!
 
more than likely it is, due to the fact that it came on while driving down the road, and not at idle. Bonus is that he will already have it out for testing so he's half way there on replacement.
 
Agree that it is best to run with a gauge. I remember as a kid the Darts and Volares my parents had would occasionally filicker the oil light at idle. Last spring the Dart I bought the previous year had the oil light come on. Sender I thought, but the light stayed on off idle more than I liked. Cut the filter open to find all kinds of carbon light crud. Car sat for years before I got it, and the curd loosened up and blocked the filter. Glad I didn't blow it off as "normal" and added a gauge.

Also had a Durango that the gauge every few months would occasionally show zero at idle. No lifter tick, etc. It was a beater with a heater at that point, and oil changes weren't high on the priority list. Treated it to an oil change one day and realized months later I never had the problem again. No it wasn't a Fram filter, infact I think it was a Purlator. Pulled the engine when I sent it to the scrap yard the 300K on the clock.
 
Last edited:
Verify the wire isn't shorting the ground, since that will light the lamp. The oil pressure switch shorts to gnd when pressure is low, and opens when OK (probably >10 psig). It lights initially as a "bulb check". Same deal w/ my 1969 slant six, oil lamp came on while driving, went away, came on 2 months later. I didn't know much then and let it sit for 4 yrs, then pulled the engine and had it rebuilt in 1986. My mom ruined the engine in our ~1962 Valiant by driving for ~1 mile after the oil lamp lit. I was ~12 yrs old and knew enough to check the oil level, which was OK, so we thought "bad sensor" and tried to find a mechanic. The engine smoked, then seized, and we wound up with a used AMC Matador station wagon, which was slick-looking.

I think in both cases what happened was the pickup screen clogged w/ gunk. An easy fix would be to drain the oil, fill the pan with 4 qt of kerosene (or diesel) and let it sit for as long as you can, then drain. If lucky, that will fix the problem. They used to sell "engine flush" that you would run and clean the whole engine innards. I recall it was just kerosene. Most people today wouldn't suggest running the engine with it in place of oil, since might damage your cam lobes. Bio-diesel cleans even better, but can attack rubber seals. Vegetable oil is the same.
 
Slant oil bypass valves have been known to stick open causing low oil pressure at idle. Easy enough to pull and clean.
 
Change the oil and filter. If it's been in a long time, and engine is tired, oil could be diluted with blow-by contaminents. Then I. would use 20/50 (geriatric) oil to compensate for wear, the lite will likely stay off, and you should get a ton more miles outta it. .jmo. cheers
 
Last edited:
You must log in or register to reply here.
-

Back
Top