Oil preasure drop when towing

[xcrtom]

This is a follow up to an old thread, I have since done 3 UOA, it showed aluminum and Iron content in the oil was high, everything else was good including viscosity. In the first 2 analysis they though the aluminum was from piston wear, but in the third they mentioned there was no lead present ( in I remember correctly) which there should have been if it had lead bearings so they speculated that it had aluminum Berings and the aluminum could be bearing wear. Iron would be cylinder liners. I haven’t had the problem as I haven’t towed a trailer a long distance. I don’t hear any knocking and the motor uses no oil for local driving and a minor amount on a trip, no trailer. I’m thinking I’ll drive it there’s a problem, and if there is probably a jasper or other reman motor. Jasper has a AFM delete option for new motors. Time will tell.

 

[eljefino]

I'd wait for your motor to get significantly worse before putting a Jasper in.

 

[spasm3]

I'll second that it could be the oil pick up o-ring.

 

[xcrtom]

I'll second that it could be the oil pick up o-ring.

I’ll have to read up on that issue but the problem shows after towing a heavy load a long distance. The oil pressure stays reduced until I change oil and then it goes back to normal. If it was the o ring, it seems it would be a constant lower pressure.

 

[xcrtom]

I'd wait for your motor to get significantly worse before putting a Jasper in.

I agree, that will only happen when motor dies, gets tired or undepenable.

 

[GMBoy]

Good morning, I just found this site last night thought I would see if I could find an answer to a problem with my truck. It's a 2012 gmc, 5.3 motor, oil pressure is high 30's when warm , no mater temperatures or driving conditions until I hook onto a trailer. After about 250 miles my preasure starts to drop to low to mid 20 lbs. This during the winter towing snowmobile trailer weighing about 4600 lbs. Apparently the oil gets heated to the point it thins out. I've changed oil sending unit and screen. I've been using Mobil 1. I've talked to several techs that have no idea, just tell me to add some Lucas oils stabilizer. Any thoughts or advice is much appreciated. Thanks Tom

If a tech recommends Lucas oil stabilizer please find a new tech.

 

[zrxkawboy]

Next time you tow, and the oil pressure drops after that, try changing just the filter and see what happens. I seem to recall a post about a similar engine with low oil pressure, where the pressure increased after a filter change.

 

[xcrtom]

Next time you tow, and the oil pressure drops after that, try changing just the filter and see what happens. I seem to recall a post about a similar engine with low oil pressure, where the pressure increased after a filter change.

I will but if it did increase it would seem that the filter is blocked.

 

[zrxkawboy]

I will but if it did increase it would seem that the filter is blocked.

Here's a recent thread on the topic. There was another one I was searching for, but can't find it right now.

Lower oil pressure mid OCI, PF48

2008 Suburban with 5.3, 161K. Changed oil in November and used AC Delco PF48 filter and Napa 5W-30 full synthetic. Have about 1800 miles on the oil change at this point. Late this week, I noticed somewhat lower oil pressure on the gauge and more fluctuation than usual. Maybe a little slower to...

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