Low oil pressure when cold.

Aaron_Johnson · February 10, 2008

2006 F-250 6.0. Unit starts fine, but has no base oil pressure when cold. Has already wrecked one turbo. truck has to run for 2-3 minutes to get oil pressure (starts and stalls for 2-3 mins). I have removed and inspected the oil pump and regulator. The filter is clean and free of metal. I have also removed the pan and checked the pickup. Found a couple pieces of metal in the pan, one looks like a piece of bearing material and one looks like leftover debris from when the block was cast. I think I am heading towards a tear-down to find my cause, does anyone have any ideas otherwise?

Bruce Amacker · February 11, 2008

2006 F-250 6.0. Unit starts fine, but has no base oil pressure when cold. Has already wrecked one turbo. truck has to run for 2-3 minutes to get oil pressure (starts and stalls for 2-3 mins). I have removed and inspected the oil pump and regulator. The filter is clean and free of metal. I have also removed the pan and checked the pickup. Found a couple pieces of metal in the pan, one looks like a piece of bearing material and one looks like leftover debris from when the block was cast. I think I am heading towards a tear-down to find my cause, does anyone have any ideas otherwise?

I assume you put a pressure gauge in to verify this, right? The oil and filter has been changed and nothing odd was seen in the housing like a melted standpipe or defective housing drain valve? The front cover looked OK where the pump gears ride?

What's hot idle oil pressure after the truck has been driven on the highway?

7.3's have a uncommon problem with gear wear in the pump. They could look fine, but did you check tooth gap like this? I had a 7.3 with a similar start and stall problem, the gap was about .012-.015" and the gears looked fine. A new pump fixed it.

Posted Image

We covered this start and stall problem in detail on a 7.3 a while back. If your pickup tube is fine and there's no suction leaks, there's a real good chance it's worn teeth on the oil pump gears or a filter drainback problem. Caution- the first bad 7.3 pump I saw "looked" OK until you got out the feeler gauges.

IH has a VT start and stall concern (I'm not sure it was a TSI) for the filter drain valve being bad. IH says:

1. Drain the oil pan (not filter) for 30 minutes.

2. Put a fresh drain pan under the truck.

3. Pull the filter loose.

4 You should get over a pint of oil in the pan from the filter housing. If not, the drain back valve is def.

I'm real big on wasting a bit of time doing diag before tearing into the engine and finding nothing. If your hot oil pressure is OK you are not likely to find anything on a teardown. I'd be rethinking the pump and drainback.

Even an oil analysis isn't a bad idea on one like this.

Good Luck!

PS On edit: The reason the oil pump causes this is because with the teeth .015" apart, it allows all of the oil galleys to drain back into the pan past the teeth. The pump is already worn, and has a hard time priming. By the time the pump primes, fills all of the galleys, and builds pressure, the HP system goes dry and loses ICP. If either this or your drainback valve was def, or both, it would account for your trouble. I'd be doing more diag before going inside the engine.

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Tony302600 · February 11, 2008

IH has a VT start and stall concern (I'm not sure it was a TSI) for the filter drain valve being bad. IH says:

1. Drain the oil pan (not filter) for 30 minutes.

2. Put a fresh drain pan under the truck.

3. Pull the filter loose.

4 You should get over a pint of oil in the pan from the filter housing. If not, the drain back valve is def.

I'm real big on wasting a bit of time doing diag before tearing into the engine and finding nothing. If your hot oil pressure is OK you are not likely to find anything on a teardown. I'd be rethinking the pump and drainback.

Even an oil analysis isn't a bad idea on one like this.

Good Luck!

PS On edit: The reason the oil pump causes this is because with the teeth .015" apart, it allows all of the oil galleys to drain back into the pan past the teeth. The pump is already worn, and has a hard time priming. By the time the pump primes, fills all of the galleys, and builds pressure, the HP system goes dry and loses ICP. If either this or your drainback valve was def, or both, it would account for your trouble. I'd be doing more diag before going inside the engine.

/forums/images/%%GRAEMLIN_URL%%/grin.gif

/forums/images/%%GRAEMLIN_URL%%/cheers.gif /forums/images/%%GRAEMLIN_URL%%/cheers.gif AWESOME INFO!!!!!!!!!!!!!!!!!!!!!!

DamageINC · February 11, 2008

Awesome bit of info there Bruce, thanks!

Dave

Aaron_Johnson · February 12, 2008

Bruce, Yes it has been verified with a guage, nothing abnormal was found with or in the oil filter housing. I checked the oil pump gears as the manual says and as you show in that pic. I have .006" between the outer gear and .008" as you show in that pic. The front cover and oil pump cover look fine, no wear or gouges. The hot oil pressure was above minimum spec through all of the ranges as per the wsm. The oil and filter were also changed before I posted. By fluke I sort of did what you said when I had the oil pan off. I took the filter out after the pan was off and judging by the ammt of oil on the floor there was more than a pint lol. I will verify by measuring next time. I cold started it again this morning and the oil pressure came right up....mind you it was only -20 this am not -40 like it has been. /forums/images/%%GRAEMLIN_URL%%/banghead.gif

Bruce Amacker · February 13, 2008

I cold started it again this morning and the oil pressure came right up....mind you it was only -20 this am not -40 like it has been.

Did you "forget" to tell us this problem occurs at -40F? /forums/images/%%GRAEMLIN_URL%%/grin.gif

What oil are you using? What ambient temp (parked outside/inside), and is it plugged in?

Jesus! /forums/images/%%GRAEMLIN_URL%%/laugh.gif

Tony302600 · February 13, 2008

/forums/images/%%GRAEMLIN_URL%%/boink3.gif /forums/images/%%GRAEMLIN_URL%%/boink3.gif use 10w30

Aaron_Johnson · February 13, 2008

lol yeah I did forget....might have something to do with working 30 days without a day off and a yard full of broken trucks /forums/images/%%GRAEMLIN_URL%%/crybaby2.gif

It was parked outside, plugged in at -40C. The block heater is working. We are using Rotella T 10w30. Maybe we should switch to 0w or 5w something.