any specific brand of oil? i was thinking of using delo 400 15w40 is that ok?

 

• My latest oil change a few days ago, I put in Castrol GTX Extended Life 10W40 augmented with a quart of the Lucas Oil Conditioner (12.99) stuff and a Mobil 1 Heavy Duty Filter that was on sale for 12 bucks. It is a lot quieter now, still an occasional rattle, put in new plugs and wires, runs much smoother and quieter aas well.

 

Yup.

I use Shell Rotella and either a NAPA oil filter or a Purolator, both run around $5.
If you keep your eyes open NAPA runs a BOGO sale on filters form time to time, when they do I buy 4 for the price of 2.

 

If you need a additive then you need a different oil.

http://www.carbibles.com/additives.html

 

I don't know if you figured out your problem but sometimes leaks in the exhaust manifolds sound like heavy tapping, the joint between the manifold and downpipe is a common leak on our trucks.

 

Very interesting Spike. I especially found the section from the ex-Ford guy very informative. I guess I kinda knew this all along I just never really thought about it. I have never used an oil additive. Gas yes, oil no. Thanks for the link.

 

Yeah I also found the ex-Ford guy thing very interesting.

 

i would explore and eliminate or confirm the cat theory. Seems like quite a common problem for vehicle this age. Pretty easy and quick to do. You need a stethoscope or something similar like a rubber hose in the ear. Warm engine up till rattle occurs at idle. move stethoscope around sump area then around cats. You should hear a distinct difference if it is one of your cats. You should be able to isolate the sound using a stethoscope. I dont know what your emmisions laws are but down here I just got em cut out and replaced with pipe. No more knocking. Hope this helps.

 

With my 97, it hs quieted way down in the last couple of weeks. I know my exhaust downpipe nuts are tight. Mine had ther occasional rattle which was described as a potenial oil pmp abou to go issue.

I added the Lucas Oil Conditioner becuase I like the idea of extra "slickness" that is demonstrated by their little display with the wheels you spin. It is running much quieter now.

I may try the Rotella on the next oil change. I am pleased with the way it's running now.

 

so i finally got the chance to go over the engine with a stethoscope after I changed the oil and the downpipes were quiet< the cats were quiet< oil pan and engine block were quiet< the only thing that i heard the tappings was from the heads and the valve covers mainly the left bank< any ides what this could be