Ford Powerstroke Diesel Forum banner

1 - 2 of 2 Posts

1 Posts
Discussion Starter #1
Hi guys, I'm sort of new here- been trollin for a long time but never had to post, as I can usually search and find what I need. Until today.

I've got an '05 F-350 6.0l crew cab lariat, 4x4, 95k, all stock except egr delete (sct tuner on the way)
The truck will not start once it is warm. I know it's fairly common, so I took care of the 'common' issues
I've replaced the IPR (it recently took a **** so had to anyways), STC fitting on the back of the hpop, oil rail dummy plugs, and all of the injector o-rings.
I don't have AE, and didn't want to buy it if I didn't have to.
I still think it's a leak somewhere because I've ran the truck for 23 hours straight and had no issues. But what else could be leaking?!?! :dunno:

As always, any help is greatly appreciated :)

Premium Member
6,293 Posts
• If the nature of the concern exists hot only (hot no starts), safely bring the vehicle up to necessary temperature range.
Monitor IPR (Injection Pressure Regulator) duty cycle as EOT (engine oil temperature) increases. A high-pressure oil leak
should be indicated by a rising IPR duty cycle.
As EOT increases and the leak rate increases,
ICP pressure can begin to drop as the IPR is
no longer capable of compensating.
• Check the operation of the IPR valve. Remove
one of the valve covers from the engine.
Apply shop-air pressure to the high-pressure
rail using special tool adapter #303-766. When
the air pressure is applied, there will be a
noticable air leak due to the IPR valve being in
an open state.
• With the WDS, increase the duty cycle of the
IPR valve. This should block that air leak. If
no change is heard, the IPR valve is not
functioning as commanded. Your concern
could be the IPR valve or the PCM to IPR
circuit. If a change in the air leak is heard, the
IPR valve is operating and investigation for
the high-pressure oil leak begins.
(you can also manually command the IPR by getting 12 volts and a ground wire attached to the pins on the IPR. DO NOT APPLY 12 VOLTS FOR LONGER THAN 60 SECONDS or IPR damage may occur.)
• With the IPR blocking the air leak to the oil pan,
listen for the position of the air leak in the
engine. A stethoscope can improve your ability
to narrow down the location of the leak.
The leak can exist in the following areas:
• Cracked/broken check valve and fitting in high-pressure oil rail, under either valve cover(s).
• Disconnected high-pressure hose(s) under valve cover(s). (03-early 04's)
• Stand pipe from high-pressure hose to the branch tube in the tappet gallery (o-ring at the bottom could be cut/torn or
• O-rings on the top and bottom of each stand pipe and/or all four plugs in the high-pressure rail.
• O-ring in between discharge tube and high-pressure pump.
• O-ring around discharge tube that fits inside high-pressure pump cover.
• High-pressure pump inlet o-ring.
• Branch tube from high-pressure pump to stand pipe in the tappet gallery.
• High-pressure oil injector o-ring (high-pressure rail connects to the injector).
NOTE: Air may leak past the high-pressure oil pump shaft seal.
This is normal and DOES NOT require pump replacement.
1 - 2 of 2 Posts