Oil/Choke idiot light coming on.

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STLRegal

G-Body Guru
Jun 22, 2007
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St.Louis
After the cars been running for a while and warms up, the light will come on or flicker when I switch from Park to Drive, or stop at a light or something. It then goes away when I start driving again. Whats the problem.
 
Sounds like you might have an oil pressure problem...the oil is thicker when its cold and when your driving your car the oil pressure is increased from the higher rpm of the engine. The idiot light comes on (I think) when the oil pressure drops to 5 pounds so I wouldn't keep driving around until you find the source of the problem. It may be the sending switch that is defective because if your pressure was that low then the valves would be making some noise.
 
Well im running 10w-30 for the last 2000 miles. Is it possible it could need a change to a heavier oil? The car also got hot a couple times when sitting in traffic a few times so that probably degraded the oil some too.
 
you should find the problem first, instead of just putting a band-aid over it. pontiacgcp is probably right. get an oil pressure tester and plug it into the sending unit port and see what you get. have the engine warmed up or tape the gauge to your windshield and drive the car. if you have low pressure it could be the bearings and putting in heavier oil may raise the pressure, but what if the bearings are shot? they can still break apart or spin and now you have a major problem needing a rebuild. if you can, find a place that does used oil analysis and send them a sample. they can look for bearing particulate.
 
It's easy to test the oil pressure so I don't suggest to try anything to hide the real problem. If it is the sender switch it's an inexpensive part and real easy to change and if it's an engine problem thicker grade oil isn't going to cure the problem.
 
I am curious, what engine is in the car? Is it the Buick V6? If so, the oil pump is shot and you need a new timing cover. When I had this problem with mine, I switched to straight 40 weight and drove it another 50k miles until I performed a mercy killing and extracted it from the car like the cancer it is, and replaced it with something better. Still ran with over 200k on it when it was pulled, and later installed in a 4 door 84 Cutlass. That car had 75k on it and had died due to low oil pressure from a faulty oil pump.
 
its the v6 3.8. If it was the oil pump woudlnt the light be on all the time and not only when the car warms up?
 
STLRegal said:
its the v6 3.8. If it was the oil pump woudlnt the light be on all the time and not only when the car warms up?

no...the pump is two gears, one is driven by the distributer shaft. The faster you rev the engine the oil pressure is increased. There is a relief valve that governs the maximum pressure. When cold the oil is thicker and provides an increased pressure at lower rpm's
 
The oil pump design is the number one killer of 3.8's. This is because many people do not change their oil regularly enough and this pump is very sensitive to proper maintenance. It was the base engine after all, and most people who bought them new were not enthusiasts. Enthusiasts tend to take better care of things while the general public ignores them until something goes wrong. I remember talking to a machine shop owner back in the mid 90's who told me he had rebuilt tons of the Buick 3.8's but virtually none of the Ford 3.8's (In Fox cars) because of the Buick's design flaw. They always spin the bearings due to oil starvation.

Now, years ago there was a kit offered that put a spacer between the filter adapter (bottom of pump) and the pump housing and supplied longer gears. This would boost the oil pressure and prolong the engine's life. These were offered for several engines with this faulty design as it is a well-known failure point, especially on AMC and Buick engines. I believe Hastings is who sold them, but am not sure they still do. Try E-Bay as sometimes you can find things there that would otherwise be difficult to search for (Use Buick V6 as the search term) . Then you can look up the company that makes the part the seller is selling and see if it is any good or available locally.
 
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