Well, I've always taken this for granted but I tow about a 7k lbs horse trailer and when I need the power there is a rather loud high pitched VRRR noise. I have always assumed it was just the turbo and it was suppossed to make that noise but while pulling the other day I had a friend who is an auto mechanic (not diesel) who stated that there was now way it should be making that noice and that it sounded like a waste gate not opening. This truck is a 350 DRW, 2002 w/ roughly 40k miles on it, auto transmisson. Now in my 2000 350 manual transmission I never heard this noise in the four years I drove it but have heard it in a friend's 99 7.3 w/ auto tranny.

Basically I'm wondering if I have a problem that needs to be looked at or if it's just normal turbo noise.

Second question is regarding power and fuel mileage. I've looked through the forums and it looks like if I want to get a chip or programmer I need gauges and possibly an exhaust mod. I'm getting poor mileage while towing, in the 11-12 mpg range at best and I could use a lil more power. Is there anything out there that I could do to give me a boost in bother areas without all the other modifacations and not giving away tell tale signs that would void my warranty?

 

I tow about 10,000lbs every so often when camping. I have an open air intake, 4" Magnaflow turbo back, Diablo Predator on the 60hp setting. I tow much better and mileage is still around 15mpg if I don't get in a hurry. 10-12mpg when I drive too fast. The tunner seems to me locks the torque converter sooner and alows you to use more of the available power because it is accually being applied to the wheels. Haveing more power also allows you to not have to shove into the throttle as much, and "in my opinion" helps in mpg. This is my experience with my truck,,and I would not go back stock now for any reason. Other than warenty work

 

1. Is the sound there while cruising or only when you get on it. If only when you get on it it could very well be the Turbo. <ost PSDs with open exhaust and some stock trucks have a very noticable turbo whine. There is a stuttering sound to it refered to as flutter that has somthing to do with the turbo interupting the exhaust (or somthing like that). If I tried to describe it it would probably be VRRRR.

2. Basic Rule if your gonna mess with the PCM you need gauges. Chips/tuners certainly mess with the PCM. You can mod exhaust and AIS without worrying to much about getting into trouble because they will in fact reduce that possibility and give you a nice increase in available power (enuff to make you smile a lot).
You may also realize some help in fuel economy. I tow an 11 K fiver, lots of weight and wind resistance, I get around 12 mpg. That seems to be about what most of my friends in the RV club get also, most have PSDs and tow fifth wheels.