Cold Operation vs Hot Operation
 

Do these beasts have a Closed Loop and Open Loop Operation as a gas engine?
The reason I ask, is the '03 seems to be making excessive injector noise from start-up through achieving full operating temp. Now the mystery...If I start the '03 and go about my merry way, from cold start till hot, never shutting down, I will have the excessive I'-rattle for as long as I drive the '03. If I shut the truck down anywhere from about half-way to hot and hot, say, for maybe 15-20 min, and re-start the engine will sound just like when she was new. No excessive I'-rattle. It almost seems as though stopping and shutting down allows the engine compartment warmth to catch up and reset something that is sticking when cold. The truck is stock with about 80g's. No codes, temp gauge seems to be reading the same as always. Hooking a ScanGauge to it and a highway ride it is getting up to 190 but as soon the city drive begins it will cool down to 180 and remains there. The only way to get rid of the excessive I'-rattle is as I said before, is to shut down and let the '03 sit for a while, fire up and all is fine.
I'm leaning toward starting with the t'stat. But I could lean elsewhere if need be. Thanks...

Since diesels don't have a throttle and don't stay within a narrow fuel/air ratio like a gas engine, the idea of closed loop doesn't really apply. Power is controlled by the amount of fuel injected, and air intake is unrestricted, so there isn't any map of proper amount of fuel for a particular throttle position at a particular RPM as there is on a closed loop gas engine, and there isn't an oxygen sensor so the ECM can adjust fuel/air ratio as there is on closed loop gas injection.

Anyway, your motor sounds better once you've stopped it for a few minutes, and I see you live in a northern climate...

How cold is it there? Might consider a winter front? Do you run an additive?

A bit of noise is normal on these... If it's staying around 180 in cold weather in town driving, I'd say the thermostat is probably OK.

The truck does it anywhere from below zero to 40F. I have a winter front. Run a little TC-W3 and a little Howes' when needed. The truck is worked not babied. I understand about the diesel noise, this is above that. Once again, after a short shut down and restart its like a switch has been turned on and it's a whole different sound....
Thanks Jeff..

Try some stanadyne or power service for a few tanks. The TCW3 may be coking the injectors.

Tony

Faaar far feched but, metal expands when it warms up. some people are saying that the clamps on the injector line come lose and they rattle a bit. I could see if you were to shut it down the metal lines could shift in to the sweet spot and not rattle. kind of stupid but you never kown. good luck

Interesting...Mr. Labrek

Have you ever adjusted your valves? I did at about 45k and it sounded like a different truck when I finished, and got better mileage too.

I have not adjusted the valves yet...But it is on the docket.
Thanks kry....

truckbouy2

I have a 03 also so know exactly what your saying. First stop running 2-stroke and Howe's. Trust me I also used them regular for months. Next DO the valve adjustment and if your injector valve bodies are good within two tanks the rattle will be gone. That is if you have not run a pressure box? For lubricity I run a low bio-diesel blend 5-15%. I'm amazed at the difference, thought for a while my injectors where going to fail....not.

I have gone crazy with noises from my engine compartment. I have resigned myself to the fact that if it gets good mileage and pulls strong, and does not produce greatly different than normal smoke...it's fine just drive and smile. I have noticed lately though the fuel I buy has very noticeable effects on mileage and engine noises.

Clean quaility fuel will make the engine seem quieter and you will get great fuel mileage. If you fill up at new place, truck is noisier, and mileage is down don't buy there again. It's not that good of quality. In your local area it is easier to buy from high quality diesel. On the road, do the best you can and no mom/pop fuel stations.