I have a job 3 purchased new last June. When it was new I remember seeing the factory boost gauge go to 35-40 psi. The truck feels down on power now so I ran a few 0-70 runs to watch the boost. It hits 20 psi even at partial throttle but it struggles to hit 28-30 and will only do it in 1 gear. Dealer checked for codes and didnt pull any. They did the 08B07 reflash this morning and I didnt see any improvement.

What kind of boost should I expect? What factors could cause it to barely hit 30 now when it hit much higher 6-7 months ago? The truck is bone stock but did have the DPF replaced in October.

Thanks in advance!!

I have seen the 05 that we have run up to 35ish when on the throttle with a load....commonly see 20 up a hill in top gear.

Oiling problem....

The 6.4 has always been one for only giving power when it was needed. All of these calculations come from a multitude of sensors (eot, iat, maf, map, ebp, etc). To diagnose a low power scenario, all of these pids need monitoring while driving in a "high boost" mode. There are reference values in the pced that have to be matched for optimal performance.

Oiling problem as in a bad pump or something like that? Or oiling problem as in wrong kind of oil, too full, too low? Is there something I can look for or a test I can run?

Follow up question. I have been making runs of 20-25 miles (empty) but thats all the further I have driven in a single trip since Christmas. I havent noticed a regen in a while so I was wondering if maybe 25 miles isnt enough to get the engine hot enough to start a regen? If not, then maybe the boost/performance is being affected by the DPF clogging?

DNFXDLI said:

I have seen the 05 that we have run up to 35ish when on the throttle with a load....commonly see 20 up a hill in top gear.

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35ish in a 6.0? Bud, I hate to say it, but head gaskets are in your future. Looks like the turbo is overboosting. Might need a cleaning. Its fun though, to have that much power (but for how long?)

blacksnapon said:

Its fun though, to have that much power (but for how long?)

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Can I answer that one?

blacksnapon said:

35ish in a 6.0? Bud, I hate to say it, but head gaskets are in your future. Looks like the turbo is overboosting. Might need a cleaning. Its fun though, to have that much power (but for how long?)

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It is not all the time....I have seen it go that high...maybe 30..the gauge is kinda small...only under wot situations....and in any case if that does happen then I guess the OL will get her wish and the engine will be done sooner...and sorry..I didn't see this was pertaining to 6.4's

DNFXDLI said:

It is not all the time....I have seen it go that high...maybe 30..the gauge is kinda small...only under wot situations....and in any case if that does happen then I guess the OL will get her wish and the engine will be done sooner...and sorry..I didn't see this was pertaining to 6.4's

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It only takes 1 time to take out the head gaskets. The turbo vanes are sticking, the acuator is bad or it is tuned and the tuner is causing the problem. If it was me i would fix this problem sooner rather than later as it is cheaper to fix the problem now.

Thanks for the input....I am getting an Espar heater in it right quick...I'll have the mechanic have a look at it.