Is my motor ok?

[EZSnow]

With fuel prices where they've been, I'm normally a "keep it below 2,000" kind of guy, but tonight I let 'er rip on an on-ramp, and was rewarded with only 12psi of boost!:eek: I have a DEAD STOCK '03 7.3- I installed the gauges to pull a 12k fiver, but haven't done any mods yet. The truck will normally push about 17psi on a full-throttle run. I ran it again to get a lookie at the pyro- never more than 1100*

Truck has 50k miles, about 15k on the fuel filter and about the same on the air filter. I'm due for an oil change, too- about 4k on that. How does an ailing turbo act? Boots? Just an air filter?

Please put my mind at ease....

Derek

[John DiMartino]

12psi is very low.If theres any hint of smoke id check for boost leaks.Your hitting 1100 empty with no mods? Thats a little high, Id check the air filter as well.Sounds like a boost leak.

[EZSnow]

How do you find a boost leak? Obviously, you can't check while the truck is under boost... is there a telltale, or just pull the boots, clean and re-set them? ALL of them, or just those on the turbo? I'll check the A/F tomorrow AM and check in here with any findings.

*Curiosity follows*

Until my remodeling project gets done, I'm commuting about 45 miles from my base of operations, all freeway. The other night there was a threat of snow, so I carried the plow 'home'. I ran with it as low as I could, and tranny and coolant stayed fine, but egt was running about 950-1025 and boost was hitting 8-10psi. Of course, I was running about 75mph... any correlation?

[John DiMartino]

i made up an adapter for the cummins.It uses the 4" inlet at the turbo,as long as yours is the same you could use it too.I made it from the hardware store fittings for about 10 bucks.One 4" to 2" rubber adapter(its in the drain pipe section where the pvc fittings are.then go from the 2" side of that down to 3/8" or 1/4" NPT.You can put an air fitting in that then, I clamp the adapter onto the turbo inlet,after removing the air fliter intake piping, make it as tight as you can.then hook it too shop air hose with the regulator set at about 10psi to start.Once its up toi 10psi i listen carefully for leaks.I have put as much as 45psi on mine looking for leaks.Id say with 20psi you should be able to find any leaks.You can spray the intercooler,and hoses with a water/soap mist and look for bubbles,but the leak will be pretty obvious. it could also be the intercooler.be careful with the adapter, if there isnt a lip on the turbo flange, it can shoot off like a cannon,dont ask me how i know!

[wyldman]

Make sure all your boot clamps are tight.It sure does sound like a boost leak.

[EZSnow]

alright- I'll give the boost leak a go.

Any chance it's a fueling problem? I just filled up on monday, at my normal station- they do 3 transports of diesel per day, and its about 4 miles from the refinery, so I can't imagine bad fuel, but I was just wondering about a fueling problem... I dunno. At 50,000 miles, I'm very much a diesel rookie.

Thanks for your suggestions- I'll report back with my findings.

[ratlover]

you looked at the little restriction suck in gauge thingy? I'd take a look at the air filter first and then start with the actual work. what did your PSD normally run for EGT's?

[EZSnow]

Originally posted by ratlover
you looked at the little restriction suck in gauge thingy?

took me a second, but I think I know what you're talking about- that yellow popup somebody gimme a new airfilter cuz I can't breathe thingy...

It was still completely pushed in.

I have some "oily residue" around the cool-side tube at the intake. Is this indicative of a leak? I hope it its, as that would be the easiest boot to get to. My imagination tells me that where there is a leak it would be blown clean... but I have been wrong once or twice before.

How does a boost leak affect the rest of the operation of the vehicle? Does it leak consistently, or is it more like a popoff- and lets go at a certain pressure? Will it damage the engine to run it until I get a chance to get after it? Does the MAP see the drop in boost and defuel accordingly? I'm not getting any smoke.

Derek