Hey guys,

So I drive a 1989 F150 w/ 5.0L V8 4 speed manual with OD. This problem has happened twice now. Once about 2 weeks ago and now just this morning. The check engine light will come on, however, it won't stay on. It will blink between 10-20 times. Then just stop. The first time I was taking a bunch of stuff to the dump, averaging about 40mph but this morning I was making my daily commute and was on the highway keeping between 55-65mph. I haven't noticed any noises, or anything unusual. Mileage has remained constant.

Has anyone else had this happen? What should I look for?

-Thanks

 

Have the codes read and report back with them.

 

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After you do that come back here. You can also use a paper clip to do this. The Check Engine Light doesn't have to be constant for a code to stay on the computer, all codes are stored. Also, get a Haynes manual, it's one of the best purchases I've made for my truck

 

I will check them and post the results. I really should know better by now. And thanks for the advice, I actually have a code reader and a Haynes, though.

 

Have had this problem before, read the code and found one of my upstream O2 sensors was setting it off, changed it and have been good ever since.