I was messing around on the highway the other day and got on the truck. Boost gauge topped out at 32 psi, but didn't feel/sound like it was really going anywhere. Almost felt like the torque converter wasn't unlocked because sometimes it'll take off and the exhaust is real loud at high speeds and others, it'll just boost and the exhaust will be quiet. I get a wrench light when towing at highway speeds, but no CEL. I did show a over/under boost code once when driving about an hour and a half up hills towing and the wrench light kept showing its face. Every time it'd come on I'd pull over, shut it down, restart and keep trucking. Anyone know why this thing is being like this?

06 f250 66k

 

The over boost could be from a dirty and or sticking turbo veins , and 32 psi is to high .

 

I would have to say sticking because the thing will haul a$$ sometimes and others it'll just boost and barely pick up speed with hardly any change in exhause tone.

 

I have hit 32 an 33 psi of boost when I had a bullydog tuner. Got that boost readout on the bullydog outlook monitor I had.

Get a SCT tuner now. Took all the bullydog stuff out. No gauges let so don't know what boost is now.

 

Mine is all stock though. No tuner what so ever

 

P0234

Turbocharger over boost detection code stored and wrench warning lamp illuminated when a turbocharger over boost condition occurs. TSB 09-24-03. The only trucks that will set an overboost code P0234 are the 05-07s with the latest ford calibration. The calibration will set the wrench light and derate after 28 PSI

 

Kind of hard to pull a trailer up a grade at 60 mph without that wrench light coming on and kicking the truck down to 45 and no throttle response because of that... how do I get this not to happen?

 

You better get this turbo thing under control B4 you Tow

Overboost will lift the Heads OFF the Deck

 

+1.

Clean the turbo, verify the VGT actuator is working, and verify the EBP and MAP sensors are functioning.

After that, it might be turbo replacement time.

 

i was wondering to how high can it go. i see 30+ psi all the time

 

IIRC you shouldnt go over 28psi Boost and at this Point the PCM should set a DTC


But you have to make shure the Boost psi your seeing is True or is the Gauge Reading it right


This is where you have to becareful with tunners

 

No tuner. And I have seen it both in the dash gauge and my pillar gauge.

As for making sure those sensors are working, how will I go about doing so?

 

the 32 psi boost I was seein on the bullydog outlook monitor mayb the reason I had to do studs an HG.

Also mayb why my EGT would hit 1300 pretty quick.

 

Over 28 psi with stk. head bolts and the head gaskets are on borrowed time. get it fixed asap.

 

That's what I'm trying to diagnose. What/ how should I diagnose those two sensors on the turbo