The bigger culprits of a tired truck

[ekfinn]

Lately I've noticed what a lot of others have noticed in their trucks-- the old girl just seems a hell of a lot more tired than she used to.

Over the last few months, I've noticed that my truck still takes off the line seemingly OK, but its ability to keep speed on hills without downshifting is gone. I used to be able to just give her a little more pedal and hear the turbo whistle a bit more and she would just take off. Towing has also become a chore. I used to be able to put an 8000 lb load behind me, and while I could definitely feel it back there I never had much trouble with it. A couple weeks ago I put a 5800 lb chevy 1500 conversion van on my 1800 lb empty dual axle tow-behind flatbed, and when I hit that steep 3/4 mile grade on the highway, halfway up I was in third gear with my foot buried into the floor to stay above 1700 RPM or risk it bleeding down. My friend whose mom's car I was towing was behind me, and he said the heat plume dumping out of my exhaust was impressive, and he could see the puff each time I shifted. My fuel economy has also declined. I'm getting about 220 miles per tank, where I'm used to 240-250 when I'm not towing. The truck just feels like it has an exhaust blockage, plugged fuel filter, and filthy air filter, all at once. I've addressed the filters this past week... just a bit of change, but not much.

I've yet to do a fuel pressure test, that's on my list of things to check today. The truck is at 164K, and it starts with the white puff of smoke followed by a couple minutes of light bluish until it gets hot. The exhaust back pressure valve seems to be working OK, as I can hear it flip open once she's warm, and I also hear it cycle on cold days on the highway. I recently buzz-tested the injectors, and they all sounded good.

If it was your rig, where would you start looking?

[BrianH]

Id start looking at fuel pressure, and check the turbo to see if its getting tired.

[ekfinn]

What am I looking at for the turbo other than checking the condition of the blades, and the runout on the shaft in the bearings?

[85_305]

Could be a few things. Could be a ratty *** air filter. Could be the stock catalytic convertor finally clogging up (I know my stock 240k cat made a HUGE negative difference in performance). Could be a turbo not boosting what it should be (verified by a boost gauge.) Could be the injectors clogged as hell (lots of diesel kleen or kerosene ran thru it in high doses). The turbo might even be dusted to where there aren't any blades left.


Now begin, and report back.



EDIT: When looking at the blades, make sure they are ALL THERE and no nicked up and bent etc. Make sure they aren't dusty. Make sure there is nearly NO shaft play.


I would do a 5" exhaust, cat delete, 3" dp, and diy 6637 intake and see how you like the truck. If you still want more, get a custom tune on the truck and you'll love it.

[ekfinn]

Originally Posted by 85_305

Could be a few things. Could be a ratty *** air filter. Could be the stock catalytic convertor finally clogging up (I know my stock 240k cat made a HUGE negative difference in performance). Could be a turbo not boosting what it should be (verified by a boost gauge.) Could be the injectors clogged as hell (lots of diesel kleen or kerosene ran thru it in high doses). The turbo might even be dusted to where there aren't any blades left.

Unfortunately my man I've already got a cat delete, 3" DP into 4" stainless Jardine exhaust. Tossed that stupid ****ing K&N and put a stock NAPA gold filter in. Changed the fuel filter. I run a cleaning fuel additive every fillup.

At this point I'm absolutely terrified that my turbo is beat to crap because I'm on a tight budget as my welding business goes belly-up before my eyes. I'll test the fuel pressure first. I'm hoping it's low, as I've got a junkyard source for a superduty electric pump setup.

[BrianH]

turbos get tired when they no longer create boost. So check for oil on the intake side of things, see if it has blow by. Stick a boost gauge on it and see how its boosting.

[ekfinn]

I don't have a guages setup for inside the truck. Is there a port on the turbo or downstream to connect a line for a guage to measure pressure directly?

[351fifty]

Drill the y pipe and tap for gauge or put it in the map line, its where mine is, but you can only read boost under load so you kind of need it in the cab.

[85_305]

Turbo's dont really get tired and just decide to stop boosting.. bad **** happens. The bearings go, seals blow out, they lose their blades and cant keep up with the work-load etc. And if any of these are the case, I'd be weary of letting your powerstroke run away. Notice being low on oil between changes? If so, how much? Does your turbo make some TERRIBLE noises sometimes?

Check shaft play too.

[lwillson]

Start with the simple stuff, take off the fuel pressure regulator, and clean the screen in it.

Screen on the tank suck tube might also have some stuff on it.

You might have lots of pressure, but not enough volume(gpm).