Join Date: Dec 2008
Location: Spokane WA. area
Thanked 990 Times in 755 Posts
Like Weld said, your oil cooler is clogged with those readings and needs attention asap.
Heres a quote of mine from another thread about turbo vane and boost readings while driving...
I road tested an 06' 6.0L with a fella I know yesterday that is experiencing the same boost variations at steady cruise speed on flat freeway...his ScanGaugeII VGT reading would jump around and be reading 53-58% then drop to 25-35% then back up again to 63% as the boost gauge was fluctuating, the whole time ICP and IPR were holding steady as was his vehicle speed.
We then jumped in my truck and drove the exact same route and speeds...my VGT would lock and hold perfectly steady at around 43% and my AutoMeter boost gauge was steady as a rock.
I'm thinkin turbo vanes are sticking too in this case, but also check the EBP tube and sensor for carbon blockage first.
Also, once your truck is warmed up and idling at a standstill, the turbo vanes should cycle back and forth between 15-85% on the VGT ScanGaugeII reading, along with exhaust tone changes, this confirms that your vanes are moving freely from open to close, and close to open.
But the turbo exhaust vanes can still stick under certain load conditions even though they look fine at idle with no load.
Jan 03' built 6.0/F250cc4wd trqsft/SCT-tuned by KEM-Performance/Garrett Powermax vg-turbo/blue spring mod/gauges=egt+boost+fuel+SG2/exhaust/airaid intake/DR 4.5 lift/dual bilsteins/315's/greasable ball joints/powerstop/smittybuilt/kc lights/high idle mod/roll-n-lock/Mobil Delvac1 ESP 5W40 with (Archoil AR9100 in the oil) and (AR6200 in the fuel)