Engine Ticking NEED HELP!
 

I have an ticking sound coming from the driver side front of my engine. Originally we thought it would be a lifter so I had all of the lifters replaced. This did nothing for the ticking sound, tried marvel mystery oil, stp, even tried a heavier weight oil still nothing. I had it stethoscoped by a certified mechanic and listened to it myself the ticking is audible on the oil pan bolt as well as on the engine on the drivers side front up top by the heads and exhaust. When you start the engine it is perfectly silent however once it is warmed up it starts ticking. engine accelerates fine and oil pressure is fine as well. I am a college student and am of limited means and cannot afford to repalce the truck at this time however I can afford to fix it if I can pin-point the issue. it is a 1995 blazer 4.3 vortec with 123000 miles any and all help is greatly appreciated im running out of ideas.

Have you ever done a tune up? What octane of gas are you running?

Without getting into describing different tick sounds, I had one that was loose exhaust header bolts. Guess it was only leaking around one exhaust port. They kept coming loose, new bolts finally fixed that.

yes I tuned it up last year new plugs, wires, distributor cap, and rotor button. I am very anal about my vehicle maintenance if the oil stays in the engine 100 miles over 3000 I go nuts. truck has a k&n cold air intake on it to and I run regular unleaded gas in it im not sure of the octane think its 87?

Ok, did you use delco? The next thing I would do is clean the egr valve. And when you put it back on get a gasket with a screen. Then try to run higher octane gas to see if it helps at all.. let me know what you find out.

yes I always use delco and used higher end wires and cap and button. would an egr valve really cause the ticking? ive had egr trouble in the past with my 94 blazer but it didnt cause anything like what im experiencing now it made my exhaust smell like sulfer and the engine wouldnt idle.

Yes a bad or dirty egr can do a lot of bad tricks to your truck. If its dirty the opening and closing of the valve will make a ticking noise. Since it only does it when warm, that would make me believe that may be the source. Its definetly worth the 15 minutes to remove and clean it. Also as stated in a previous post, make sure the exhaust bolts are tight.

I have narrowed the issue down to something with the valve train either rocker arms, a valve spring, or something to do with the valves themselves. once I figure out what it is I will post so this might help someone else.

Good deduction ! You are correct - For some reason , I have found on occasion that the rocker arm nuts with "positive stop" shoulders will indeed loosen and back off enough to allow the rocker arm to practically fall off . The lifter unloaded sounded like rapid "hand-clapping" with the engine idle - cam lobes may be damaged if continued to run ... push rod could bend ect. Recommend pulling valve cover(s) to inspect visually

If you havent solve the problem, there is another reason for the tick. since you have done a tune up, check the spar plugs, they might be loose. I had a similar problem with my truck and one of my spar plug wasnt tight