Is HPFP leak into motor possible

Has anyone had their hpfp leak into the engine. Is it even possible for it to do so. Been tracing down problems on this motor. I have a fuel leak into the oil. Put roughly 4 gallons in 25 miles.

I've put new injector orings
Injector lines
Heads are new

Yes it can. Especially if it's a remand pump. And if the injector lines aren't torqued correctly.

It's the factory pump. 114k on it. Just put a a1000 on the truck with the motor rebuild

Yes it is possible, but I'm not going to say for sure that is your issue. I can't remember the procedure for checking that, hopefully someone else will chime in. Could be an injector as well. If I remeber correctly, if you have the truck at idle and increase injection pressure using IDS or equivalent scan tool, it may show a problem with an injector(s) that isn't noticed under normal conditions.

I think if you open the oil drain, drain all the oil out, command the low pressure fuel pump on, look to see if fuel comes out the oil drain. I believe that was the procedure. Worth a shot I'm sure as you will be draining the oil soon with that much dilution.

When did this problem start to occur?

Ya I've had that done. Found nothing with the injectors
None of the lines from the rails to the injectors are leaking under pressure.

I haven't tried with the oil drain plug out to see if anything drains out.

The motor is new rebuilt. I've had the issue from start up

Whats the low pressure fuel system pressure set at. If its too high it can push fuel past the seal.

I would check the low pressure systems supply pressure first. Then move to the injector lines and make sure they arent loose. If you still don't find anything have somebody do a check with IDS to get the pressure up high enough to make it leak(unless you can make a file with MCC to command 24k rail) And if all that checks out you could very well have a cracked head.

Low pressure is set at 12psi. Injector lines are tight and new Orings on the injectors have been replaced.

IHPowerstroke7.3 said:

Yes it is possible, but I'm not going to say for sure that is your issue. I can't remember the procedure for checking that, hopefully someone else will chime in. Could be an injector as well. If I remeber correctly, if you have the truck at idle and increase injection pressure using IDS or equivalent scan tool, it may show a problem with an injector(s) that isn't noticed under normal conditions.

I think if you open the oil drain, drain all the oil out, command the low pressure fuel pump on, look to see if fuel comes out the oil drain. I believe that was the procedure. Worth a shot I'm sure as you will be draining the oil soon with that much dilution.

When did this problem start to occur?

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Definately a good idea!

12 psi is probably too much for that stock pump, im betting its pushed the seal out or that old worn out seal just cant take it anymore

What should the pressure be set at. I'm going pull the pump and check it out.

I think the stock pressure is around 3-5 psi. But I'm not positive on that. I think a lot of guys run 10 psi, but some have run as high as 20. But that I think is a bit much. Dustin is a great guy to get you squared away on this!

This motor really makes me love my 7.3s all that much more.

Anyone selling new pumps or is everything remans

yup these engines are awesome LOL


like stated above the pressure from the factory is 3-5 psi, there is a transfer pump built into the injection pump so basically all the stock pump needs is pressure no vacuum so to speak. i ran my air dog at 10 psi but realisitcally it ran about 7 psi under a load.

No as far as i know the only thing available is reman pumps. Sucks to replace that thing just for the damn seal leaking too.

There isn't any way to change just the seal is there?

Lmgrpowerstroke said:

This motor really makes me love my 7.3s all that much more.

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Simplicity makes reliability!

powerstroked08 said:

There isn't any way to change just the seal is there?

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man i gotta get with haller i could have swore he found a seal to put in one but im not sure if it worked, i think at that point the pump was hurt and pushed the seal out again.

Ahh ok. It would be nice to have a seal that would work, that way if you get a reman pump thats leaking you don't have to return it. Just change the seal an your good.(as long as its still good otherwise)