I have a tapping sound when I first start the truck in the AM. It lasts a few minutes and then slowly disappears. Now, I have a steady-on check engine light as well.

 

I would get a pressure tester and test your oil pressure at were the oil pressure sensor screws in, you might have what is called bleed down of oil from your valve covers and so if your having bleed down then there is an oil pressure leak somewhere. So that brings up this question are you leaking oil anywhere???

 

First, have you checked your oil level? Also, what weight oil are you using and when was the last time you had it changed. How cold is it in your area right now?

On the CEL, if you have any Autozones or Advanced Autos in your area, they can scan the codes for free for many of the s-series years. We will have to know what it is you are driving to help out further... Year, engine, drivetrain, and other applicable options that you feel like sharing will help greatly. Place this information in your signature (in your profile) and attach it to your posts when asking for help.

 

It's a2001 4.3 .the oil gauge reads normal no oil leaks . The truck runs fine but the tapping sound is taking longer to quite down .

 

Well like swartlkk said get the code read and come back to us with the code please!! Another idea I have that I am still going with the bleed down situation but I may be proven wrong is that in the oil filter there is a seal and if that seal is bad it will create bleed down as well even with no leaks. So let us know what the code is and we will go further!!

 

What about the other questions I asked?? Oil weight (10w30 or 5w30)? How long since your last oil change? What type of filter are you using? How is the oil level?

 

I agree with that as well swartlkk!!!

 

Pureolator filter 10w40 oil changed oil 2weeks ago .no oil leak's oil level on dip. stick at full mark

 

10w40 is completely wrong for your motor. 5w30 is what is recommended for year round use unless you are in like Arizona or some similar climate. Sounds like your oil is too thick to properly pump up the lifters upon initial start when cold.

 

Ive run nothing but 10w40 or 10w30 in my blazer and as of right now I have 10w40 in it and the temperatures here in wyoming have been as low as -20F and I have had no problems what so ever with 135K on ive had no oil leaks and oil pressure is still the same. If your having the clicking noise in the morning sounds like your lifters could be bleeding down overnight after it sits.