Stock 01 6.0 Liter Valve Rattle

[SixliterHD]

What could be causing this?

Im using 93 octane gas.

Its feeling like its straining to go anywhere.

The fuel filter and air filter has just been changed. It has 70,000 miles on it.

It also has a knock when I 1st crank it up Im using Castrol 20/50 in it.

Did I just buy a lemon? or is this a common problem and easily fixed?

I have been seeing this Lucas Oil Treatment is it any good. I really dont want a "snake oil" that covers the sound Id like to fix the problem.

Im wanting to get a tune but I want to fix the bugs 1st.

Thanks for the help

[rckrzy1]

you bought a Knockerado, do a search for CSK cold start knock.
Also 20/50 ? I don't think I'd go that route at all. The factory
calls for 5-30 you know.

[SixliterHD]

Thanks man. Im thinking about going with Mobil 1 just not sure what vis to use. Any ideas?

[Hit Man X]

At 85K I don't have CSK. I run M1 in mine, 5W30. I have since about 37K mi or so. Before M1 I ran Valvoline.

20W50 seems a bit thick. I'd run that if your oil pressure was low or it was always hot. Also a thinner oil, will equal a bit more power and economy.

Here's a few things to try:

1. Change the PCV. It's like $3. The PCV sys on the Gen IIIs for lack of a better term sucks. I change mine all the time. Oil gets into it rather easily and gums it up. Every 5K to 10K max I'd change it. Again, it's $3 and will take maybe 5 min to swap.

2. Run a can or two of some Top Engine Cleaner through your truck. GM makes it, Ford has some, or the over the counter SeaFoam works too. Chances are there's LOTS of crap build up in the chambers. Most of it is oil from the PCV system as it sucks it back into the intake tract then into where air is supposed to flow.

[00stepsyde]

where is the pcv on these motors I have 64k and have never changed it.

[Hit Man X]

Originally posted by 00stepsyde@Jan 31 2005, 09:00 PM
where is the pcv on these motors I have 64k and have never changed it.

It's on the drivers valve cover by the firewall. It's got a big vac line from the intake manifold to the PCV to it.

[SixliterHD]

Will a faulty PCV valve cause it to feel sluggish and like its just not wanting to go anywhere unless Im at WOT?

[Hit Man X]

Originally posted by silverado5.3@Feb 2 2005, 12:44 PM
Will a faulty PCV valve cause it to feel sluggish and like its just not wanting to go anywhere unless Im at WOT?

I don't think so. It's job is to allow the crankcase to breathe.

[RedHeartbeat]

Damn, my post disappeared. Sounds like maybe you have a plugged cat. I don't know how you could test it short of just remove and replace. If you have sensors before and after and both sensors are enabled in the PCM setup, the PCM should diagnose it's efficiency for you.

[SixliterHD]

I know its to help the crankcase breath. but im thinking that if its not breathing its not alowing it to spin up properly


So how can I see the efficency in my PCM