Dash oil light ('idiot light')

oldsmobile
cutlass

#1

'98 Olds Cutlass, 301 V6, 233K miles. Only intake manifold gaskets replaced (other than normal stuff like starter, water pump, alternator, plugs & wires).



Oil light has started to come ‘on’ AFTER the engine (or oil) heats up and BELOW 1200-1500 RPM. Went to fully synthetic at first, then 10W40 standard with a pint of ‘Restore’. Helped slightly. Oil light comes on about 1200 RPM and below. Have had suggestions to use Lucas instead of Restore. No bearing or lifter noise, and doesn’t burn it.



Thanks for any help/advice in advance since I need to keep the car as long as possible due to lack of $.


#2

If your oil LEVEL is OK, I would have the oil pressure properly tested; your oil pump could be on its last legs.

A 1998 car with 233K miles is certainly not worn out if it has had normal maintenance.


#3

“A 1998 car with 233K miles is certainly not worn out if it has had normal maintenance.”

If it’s not worn out, then what is it??

You could try replacing the oil pressure sender that is making the light come on…Replacing oil pumps seldom works as that is the best lubricated part on the engine…


#4

Sounds like worn bearing, no surprise at 233k miles. If using the highest-weight oil allowed by your manual doesn’t help, you can just live with it, knowing that some time the engine will fail, but you’ll have quite a bit of warning (noise) beforehand. Or replace the engine, but not likely worth that.


#5

The engine has high mileage and if the engine oil was previously diluted from coolant there’s a strong possibility the crank journals and bearings are worn and/or washed out.
This can occur without the engine making any noise.

Agreed, change the oil pressure sending unit and hope for the best. My gut feeling is that your engine is in trouble and you may have to step up to 20/50 oil in the summertime as a stopgap measure.


#6

There has to be SOME wear on an engine with 233k miles on it. However, I would drive it (carefully) until it really becomes evident that it is failing.


#7

Change the sender. Forget the “mechanic in a can” goop. If it proves to be low(er) pressure buy 20w-50. I doubt that this is the case since you report no valve noise. If the bearings were leaking that badly, the lifters would be clacking away to beat the band.


#8

it sounds to me, (mr shade tree) that you have bearring wear that is causing low oil pressure once the oil heats up. Since you say there is no clacking of the valve train, and no knock (bad engine noise) and no unusual oil consumption, I think you may be able to fix this. One, do have a gauge put on it by a mechanic to test if it is the sender or the actual oil pressure. Two, a new set of bearings can do wonders for a car if the journals are not yet badly worn.