My truck has about 14k miles on it and was running very strong until about 5500 miles ago. The turbo started making an intermittent whistling noise and the acceleration was not what it was. Several hills in the area that it used to accelerate up in sixth gear at about 1/3-1/2 throttle started to require more throttle and it is now to the point that a downshift is required. The turbo no longer makes any noise at all and there is no indication that it is working. On level ground it will tach to around 30000 rpm in 1,2,3,4, but as gears go up it seems to "hesitate" at around 2500. It will touch 3000 (slowly) in 5, but will not hit over about 2800 (very slowly) in 6, it will go to 3000 readily at idle (no load). No towing ever.
Truck is serviced regularly, all filters changed, fuel is same used all along, all clamps have been checked for tightness. Dealer checked turbo boost with computer on ride along and it showed 48 psi back when it was still whistling. No CE light ever and no codes with exception of A4-02 when using trip odometer diagnostics. No exhaust smoke noted.

Dealer keeps saying " Dunno, drive it a few more miles and see what it does". No guages as dealer says voided warranty will result. Fuel consumption doesn't appear to have changed noticeably.

Question- Are the fuel system pumps failing or is it a turbo problem? Could it be TPS or other sensor? Can TPS be recalibrated ala APPS reset procedure?

Sorry for long post, but there is a lot of knowledge here, Thanks for your help.

 

That dealer needs a pull to get his head out.. Gauges void warrenty??? How would that affect the engine at all??? Back to school.

Anyway.. 48 psi must be a typo... Typically around 26-28 I think is stock on a 600. As far as whistling it sounds to me like a boost leak. Which also could be intake manifold bolts loose. I would make sure you open the hood ans aquaint these guys with the engine and get them away from the computer..

Sounds like the lift pump may be coughing or maybe the fuel regulator return valve on the lazy issue.

J-eh

 

Your turbo is working, if not the maximum speed you could acheive would be around 40-43 mph, and the manifold pressure sensor would be setting an error code.

The way you describe the problem, I would suspect a fueling problem with the lift pump. The electronics are pretty intelligent by the time they got around to the 04.5, so the dealer should be reading an error code associated with the poor performance.

If the dealer cannot read a code, get you hands on some Hydrotex PowerKleen and treat a tank of fuel. It may be that you picked up a load of bad fuel, or are not driving the rig enough to burn the deposits off the injectors. Either way, the injectors will grow deposits on the tips and your performance will go out the window right along with your fuel mileage.

It in totally unwise to rev the engine above 1,250 without a load. Reving them up without a load is a real good way to crack a piston or loosen a bearing.

 

I guess from now on I will have to shut the engine down to come down a hill What do you think happens when you run 3000 down a long hill for ten minutes? It will not hurt the engine to sit on "high idle" for a few minutes. High idle is called wot on this board. The two cycle Detroits were broken in that way after a rebuild.... throw a brick on the throttle and go have coffee. In nice terms it was 30 minutes running at "high idle"

 

Bare reving the engine shouldn't do damage up to governed speed.

I wouldn't follow that advice....

 

Thanks guys for help on this problem.

RCW, the 3k idle was at dealer and was only a quick stab on the pedal to see what it did with computer on it.

Lil Dog, the OBDC readout did say 48 psi as I saw it. I'm not sure what parameter he was checking however as I'm not at all familiar with this test, he said it was boost pressure. I questioned him about the reading and he said STAR tech said reading normal. I do agree with your observation of 28 psi as most guages for stock install are only calibrated to 30 psi.( I'm wondering if it was guaged in such a manner that atmospheric pressure should be subtracted making the actual boost aound 33 psi?)

Well, I guess it's now a matter of waiting for failure (probably late at night and far away) in such a blatant manner that even dealer can find it . Additionally there is the indignity of getting dusted by other brands as mine won't get out of it's own way

Again, thanks to all for help.

 

No matter what your doing your going to have to hook up a boost guage to confirm the boost pressure.

Your problem could be as simple as a stuck wastegate and its de-fueling...

Or your going to have to take it to a different dealer to get answers...

I still say there is no replacement for good ol' fashioned guages... Fuel, Boost, Pyro... It will tell you stories of what you engine is doing (or in this case NOT doing!)

 

Would have been interesting to see if the rail pressure reading was meeting the target pressure reading. I've had a couple with low power on grades that had fuel issues. While leaning on it hard pulling a hill the target rail psi was 24,000, but the actual was 16,000. I believe that one ended up getting a lift pump. The other one I was unable to fix and the customer left with the truck as is (traveler passing through).

 

Sounds like your dealer needs a clue Maybe you can get ahold of D/C regional rep. and have them come out to dealer and go for a ride with you, show them it's not working right, and ask them why the heck putting gauges in is a bad thing, as they are invaluable tools for diagnostic purposes!!! This kind of situation is exactly the thing to make people say "I will never buy another ________ vehicle again" even after they fix it. Another option would be to take it to somebody who cares, have them test fuel pressure and boost, etc. and if they find a problem, take the results to D/C and tell them to fix it. The odd thing about your tale is that a performance issure is usually accompanied by a decrease in fuel economy. Not to offend you, but are we getting the whole story? Maybe something you forgot or didn't think would affect the problem.

 

Riderdog,
I suggest that you replace your fuel filter. Might be an easy answer to your problem and it is not expensive or time consuming.

 

Hi all, appreciate further input on this problem.

SBishop-fuel and air filters have been changed by dealer, thus their wait and see attitude (no luck so far).

WildBill-no offense taken, I stated that fuel consumption did not change NOTICEABLY, I have logged all fuel through this truck since new, hand calculation shows about a 3.5 mpg difference in useage over it's history, lowest was about 14.3mpg, highest about 17.9mpg, therefore I don't know with any certainty if or how much it has changed. The overhead mileage indicator is useless as it shows values as high as 23mpg at reset to 19.3 at refuel and is always 2.5 to 6 mpg off (high) from hand figures.(This is another thing that the dealer can't fix.) Thanks for the rant on my behalf.

JBODY/Mopar1973man, I will be going back to original dealer one last time and will mention your thoughts, maybe they will check items you suggested.

This was a heckuva truck when running right, I know it can be fixed if I can just find someone who cares more about customer satisfaction than $$$$$$$$.

Thanks again for all your ideas/suggestions.