Originally Posted by primalurges

Replacing the solenoids will change the sound but not because the solenoids are bad but rather if you have an 04, the new part has a smaller diameter opening likely producing more oil pressure in the phasers. Before you consider spending a couple hundred bucks you may want to modify the solenoid so that it functions like the new part. I was able to do it for about a dime using a 4mm stainless washer that fits perfectly snug inside the existing washer at the end of the solenoid. By doing this my truck has quieted down enough to where I no longer hear the diesel sound inthe cabin while the windows are open. my sound too like zippers is really only noticable on the passenger side and is louder under the truck. The chain theory is possible but now that my ticking is gone and only hear the low frequency diesel churn so Im thinking something else. There is a TSB for the fan clutch on the 04 for a sound that it make when cold, upon initial start up for about 10 seconds the fan will sound as if an electric fan is cycling off and on. I'm wondering if this fan is responsible for the diesel sound once its warmed up?

Originally Posted by bossman15

So in order to insert the washer you have to remove the snap ring at the bottom an put it behind the washer already in place?

Originally Posted by StuckZipper

I did also notice that when I put 93 in the tank the noise does seem to go away. Now, I want to heavily stress that I know the noise I had experienced was certainly louder than injector tick. The injectors were not the source, but could it be related? I think so. Perhaps when the higher octane is used (since it's not blended with the ethanol garbage) that could also help lubricate the top end... the puzzle falls together a little smoother, and everything runs a little better. I'd say that even with gas at $3.47/gallon (3.67 for premium) the additional $6.00 PER TANK (`30 gal - which is high end) of gas is well worth a shot. I will do this for the next several tanks to ensure that all of the fuel in the tank is in fact premium, and see if the noise persists with the tuner set to stock. Should be interesting.

Also, as I said earlier, I don't think that the VCT was the stand alone solution, but it played a key role in the big picture. Know what I mean? If one piece of the puzzle is upside down, the other pieces don't fit as well... (for lack of a better way to explain)

Originally Posted by Bigdawg5565

My question would be (and please excuse me if it's already been asked) is there any relation between the regular 87 octane fuel and using E-85 in conjunction with the dieseling sounds? Does one fuel produce it more or less than the other? Perhaps not as easy to figure out if only the flex fuel folks can test it if they already have the dieseling noises.