I Know about the gm ticking and all that but i think i may have a different problem. I have a 99 4.8 with 97k miles. I have a ticking sound coming from the drivers side of the engine compartment whent he truck is running. The weird thing is, if i start it and let it idle for 10 min the ticking is not there anymore for the time i use the truck. This ticking is loud, almost as loud as my flowmaster exhaust. Is this the chevy tick? or could it be knock sensors. I dont think its an exhaust leak because it goes away if the truck is able to idle for a while. When the truck is warmed up without idling for 10 mins or more the ticking remains. Fresh oil change again today, no change. Thowing no codes. I also have almost No low end power.

 

Mine seems to be doing the same thing tic tic tic and I have lost enough power to where the truck is just barely a bit faster than it was with the 100shot than it used to be with out it. I have been told everything from exhaust leak, clogged cats, unmetered air getting into the intake, spark wires arking, 02 sensors detecting a lean condition and pulling timing, knock sensors, etc. I have changed spark plugs and nothing abnormal, I also know that piston slap is normal for our trucks, but if your losing power its something else. TTT for ya

 

It might be carbon build-up. There is very little clearance between the pistons and the head at top dead center. The carbon buildup can bring those two things into contact. Enough carbon can increase compression. Also, carbon acts like an insulator allowing the exposed surface of the carbon to reach high temperatures and induce detonation. That combined with the high effective compression may be causing knock which could be picked up by the knock sensor which could cause a decrease in timing advance causing your power loss. *whew*

 

Anything you can run through the fuel tank to clean them up? Or would you have to pull the heads?

 

GM Top Engine Cleaner works best. Many people have also had success with Sea Foam although it can cost you a set of plugs.

The Top Engine Cleaner is administered through the throttle body with the engine running. Not sure how the Sea Foam treatment goes.

 

Could it be a lifter going down? If the seafoam doesnt work, put 1 quart of marvel mystery oil in on the next oil change or if you re a quart low. Run it about 1000 miles and it should pump it back up.

 

hmmm when i try that i will let you know how it goes.

 

97000 is tune up time IMO. new plugs, wires, fuel filter.

gm top engine cleaner is probably the best route to go. they run cleaner through the throttle body, and clean the injectors by running the truck directly off of a can of cleaner(no gas). then they put some crap in you gas tank and thats as clean as it gets. could also try high milage oil.

if you dont have the cash for that treatment(200+-) seafoam is your next best bet. ive heard that seafoam can be put in the oil to clean the bottom end but never heard of anyone actually doing it. no promises that this will fix the prob, but thats what i would try before putting a for sale sign on it.

 

Never heard that one, this could actually be my problem, my plugs were black when I pulled them the last three times and that is how they have always been so I just thought it was the norm. I think my truck has ran rich since I have had it because I can smell the strong fumes comming from the exhaust.

 

Your plugs should not be black under normal driving conditions. The outer base of the end of the plug may be black but the center porcelin should be a brown/white and the end electrode should be lighter. Lazy o2's can cause a rich condition and not throw a code. They are working but respond too slowly. A couple of tanks of 93 should make the detonation problem go away temporarily or surpress it enough to tell a difference, if that is a problem. If you have been running rich for some time the converters may be stopped up.
This may be contradicting of the rich problem but have you changed the fuel filter lately. They need to be changed at least every 50k. I have noticed significant seat of the pants feel by changing one in that little of time.