Ford Power Stroke Nation banner

1 - 11 of 11 Posts

·
Registered
Joined
·
181 Posts
Discussion Starter #1
working on an 04 f350, truck cuts out/bucks only under high boost/load. took a gauge and installed it inline with degas bottle and saw the press at normal 15-16psi. when you give it full throttle going uphill it jumps to 21psi and when let off drops back to normal. im leaning towards head gaskets? truck runs and drives fine untill full boost kicks in.
 

·
Captain Negativity!
Joined
·
3,109 Posts
Put down the pressure tester. Hook up a scan tool and datalog what is going on... While you might have a headgasket issue, the bucking could be a symptom of something else.
 

·
Diesel Sled Head
Joined
·
1,101 Posts
Definitely head gaskets with 21 psi coolant pressure under load. Head gaskets and look at turbo when apart and verify fuel pressure whan done.
 

·
Registered
Joined
·
1,984 Posts
The bucking doesn't sound like a hg if the coolant is puking our of the bottle proably hg. As far as the bucking mine did that and it was icp sensor.
 

·
Registered
Joined
·
181 Posts
Discussion Starter #6
I can watch the pressure gauge rise from 16psi to 21 only under full boost no other time, and it is pushing coolant out of degas bottle, found the bucking problem, when under full boost the ipr is 85% so I'm thinking it has a failing hpop
 

·
Registered
Joined
·
360 Posts
Definitely head gaskets with 21 psi coolant pressure under load. Head gaskets and look at turbo when apart and verify fuel pressure whan done.
You sure about that? How high does the EBP get when at WOT? It's more than 21psi.

I can watch the pressure gauge rise from 16psi to 21 only under full boost no other time, and it is pushing coolant out of degas bottle, found the bucking problem, when under full boost the ipr is 85% so I'm thinking it has a failing hpop
You might also have a high pressure leak, or a bad IPR causing the duty cycle to run that high.
 

·
Captain Negativity!
Joined
·
3,109 Posts
If it's going to 85% then its probably hitting the pump pop off. Is there a tune in the truck?
 

·
Registered
Joined
·
1,554 Posts
Is this a early 04'( old style pump) or a late 04' (new style pump, with icp sensor on the pass side valve cover)??

If its a early 04' the ICP sensor is on the HPpump cover, they can leak oil into the connector and cause drivability concerns, usually bucking and jerking as you described.
Also if the IPR is at 85% you need to first verify that the LPO system is keeping up, if it is then, you need to check for a HPO leak or a contaminated IPR, inspect the IPR screen, if no leaks are founs and the IPR screen has metal in it suspect a worn HPOP.

Pushing coolant out of the degas bottle under load usually indicated a HG problem, however a EGR cooler that is starting to fail can allow exhaust gassed to enter the cooling system as well, so I would first verify that the EGR cooler isnt leaking. What are your ECT and EOT temps when this happens?
 

·
Fixing Broken Stuff
Joined
·
2,078 Posts
Any codes? What is your ICP doing?
 
1 - 11 of 11 Posts
Top