2001 7.3 High Pop Empty
Cargo Master
Joined: Apr 2022
Posts: 3,203
Likes: 1,704
Years ago I ran into a similar issue where the lpop had worn into the timing cover causing a no start but I don’t recall the hpop reservoir draining without cranking. I would start at the top and work my way down. The last thing I would want to do is pull engine to check pickup tube.
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Fleet Mechanic
Joined: Dec 2006
Posts: 1,388
Likes: 6
I filled hpop reservoir twice after finding empty, sat overnight and both times reservoir was empty from just sitting. I did however both times crank motor right after toping reservoir off to see if oil was pushed out of fill hole while cranking motor but nothing. So my question is how can hpop res oil empty in oil pan after sitting overnight. If the lpop has failed could oil drain back down through tube that feeds hpop from lpop into oil pan? There are no leaks in valley or ground, oil is some how making its way back to oil pan.
Cargo Master
Joined: Apr 2022
Posts: 3,203
Likes: 1,704
I filled hpop reservoir twice after finding empty, sat overnight and both times reservoir was empty from just sitting. I did however both times crank motor right after toping reservoir off to see if oil was pushed out of fill hole while cranking motor but nothing. So my question is how can hpop res oil empty in oil pan after sitting overnight. If the lpop has failed could oil drain back down through tube that feeds hpop from lpop into oil pan? There are no leaks in valley or ground, oil is some how making its way back to oil pan.
Lead Driver
Joined: Oct 2005
Posts: 6,129
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From: Ponca City, OK
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Fleet Mechanic
Joined: Dec 2006
Posts: 1,388
Likes: 6
It's hard to say if the lpop is good or not. There are some tests you can try to hopefully figure it out. The main one that comes to mind at the moment is to hook a mechanical pressure gauge to the test port on the oil filter housing to see if the lpop is moving oil and able to build some pressure. The oil gets to the reservoir through a passage that goes back and forth a couple times between the block and front cover. Just before the oil goes into the front cover and up into the reservoir it has to pass through a back pressure/check valve up in the top of the block front just left of the reservoir. It's the square drive pipe plug there by the driver's cylinder head. You can check it if you want but fair warning it's a bi*ch to get back in and I've never heard of one actually failing. If you want to read up on it you can Google the short circuit valve that should get you all the info you want. Now wether or not the reservoir gaskets is the cause of your no start I couldn't say. As always anything is possible. You've got to replace the gasket either way so kind of moot at the moment.
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Fleet Mechanic
Joined: Dec 2006
Posts: 1,388
Likes: 6
To sum up what we have learned so far is oil not flowing out of hpop reservoir while cranking engine pointing to bad lpop. Edit batteries are not at full strength so not sure if that will matter in regards to bad lpop, oil being pushed out of reservoir fill hole. . Reservoir leaking down after adding a quart and sitting overnight. Oil pan overfilled from hpop reservoir oil bleeding into oil pan. Truck does not start after reservoir being filled. Possible to in fact have a bad gasket under reservoir and shot lpop at the same time?
Cargo Master
Joined: Apr 2022
Posts: 3,203
Likes: 1,704
Anything is possible. What I would do is fill hpop reservoir and leave plug out. Hook jumper cables up. Give it a good starting like 30 seconds or so and see if your getting any oil up to the reservoir or not. Then go from there. If no oil making it up there then sounds like a main issue is the low pressure oil problem. Get that sorted out then start on the hpop reservoir draining problem.
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Lead Driver
Joined: Oct 2005
Posts: 6,129
Likes: 1,919
From: Ponca City, OK
Anything is possible. What I would do is fill hpop reservoir and leave plug out. Hook jumper cables up. Give it a good starting like 30 seconds or so and see if your getting any oil up to the reservoir or not. Then go from there. If no oil making it up there then sounds like a main issue is the low pressure oil problem. Get that sorted out then start on the hpop reservoir draining problem.
Cargo Master
Joined: Apr 2022
Posts: 3,203
Likes: 1,704
Lpop looks fine to me. It's definitely getting plenty of oil to hpop reservoir. Put plug back in and crank while watching forscan and see what icp and ipr are showing and report back.
I don't believe it's a low pressure oil problem at all.
I don't believe it's a low pressure oil problem at all.
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Fleet Mechanic
Joined: Dec 2006
Posts: 1,388
Likes: 6
What should I see in regards to icp and ipr readings?
Thanks.