flickering engine light sometimes

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flickering engine light sometimes

April 15, 2010, 09:39:14 PM

what would cause the engine light to flicker and sometimes come on when you come to an idle while in drive. sometimes it happens when in reverse backing up and turning the steering wheel.
the car is a 1984 cougar with the 3.8 v 6. i know the engine light is also used as the temp light on this car. its not overheating . also if it starts to flicker when you come to an idle and you give it oh the slightest bit of gas it stops flickering. also it does not do it in park, and it does not do it when first started and also it usually happens at least 15 minutes after being started. im thinking of some type of vaccum leak?
thanks for any help
eddie

flickering engine light sometimes

Reply #1 – April 15, 2010, 09:42:51 PM

Weak oil pump , or excessive bearing clearance would be my first guess.
A liquid bandage such as motor-medic or STP might alleviate the symptom for a time

flickering engine light sometimes

Reply #2 – April 15, 2010, 10:06:36 PM

do you hear any noises coming from the engine after it warms up?
I bet it only does it after about 10 min, and only when you stop or are slowing down... every time
mine did that too..

flickering engine light sometimes

Reply #3 – April 15, 2010, 10:25:23 PM

As was alluded to, it is more than likely low oil pressure. the 3.8 and 5.0 are pretty well known for this behavior. If you drive it with sanity, it will last quite a while like that. If you pull trailers, or have a lead foot (or both) it won't last.

It happens after it warms up due to the oil thinning out when it heats up. This drops the pressure enough to make the light flicker at idle. As the RPMs increase, the pump pumps harder, pressure is back up, light goes out.

You can run thicker oil to band-aid the situation. The best solution is to drop the pan, replace the oil pump, and while you are in there, do your rod and main bearings. That's not easy to do yourself, and not cheap to have somebody else do. Just run thicker oil and drive it easy :hick:

flickering engine light sometimes

Reply #4 – April 15, 2010, 10:58:08 PM

get a tachometer and adjust your idle properly before assuming the worst.

flickering engine light sometimes

Reply #5 – April 17, 2010, 11:27:54 AM

yup thats when it does it after about 10 min. and no noises from the engine.... smooth sounding well for a 3.8 anyway. even when the light does light up all the way if i dont give it that little extra gas , it doesnt make any noises. i guess the 3.8's are not as hardy as the 5.0. when i had my 1985 5.0 it went to about 294,000 with out any engine work when the oil light came on and then it just started banging.
thanks guys i will post what happens.

flickering engine light sometimes

Reply #6 – April 17, 2010, 12:10:49 PM

If it's at all possible...Put a oil pressure gauge on the car. Mine started out at 55 lbs and would drop to 1 lb after 10 min of it running. the main bearings were worn in mine. Another reason for my 5.0 swap in my project.

flickering engine light sometimes

Reply #7 – April 17, 2010, 12:28:03 PM

Quote from: daminc;318628

If it's at all possible...Put a oil pressure gauge on the car.

Should've been the FIRST advice given...easy enough to figure the obvious next step from there