austinado16
Full Access Member
- Joined
- May 25, 2012
- Posts
- 611
- Reaction score
- 222
- Location
- Central Coast, CA
- First Name
- Todd
- Truck Year
- 1990 w/307k miles on the clock
- Truck Model
- GMC V1500 Suburban SLE
- Engine Size
- 5.7L TBI/4L60/3.42's
1990 Suburban with SBC....
Ever since buying our 'burb in 2004, with 225k on the original engine, the oil pressure has only readL
COLD: about a needle width past the 30psi mark during cold running, idle, or rev'd.
HOT: a needle with or so below the 30, idle and about on 30 hot at cruise speed (2,000rpm).
It's has always had a dull, *knock........knock.......knock..........knock* during initial cold start that goes away in about 1-2 seconds. Doesn't always do it cold, but usually. Might do it on a hot start, but that's pretty rare.
I've never trusted the gauge, figuring that if the oil pressure was really that low, it would have already grenaded, especially since we tow in the heat, and in the mountains with it. For example, 12hrs non-stop each way, to and from Grand Canyon, AZ to here in SoCal in triple digit heat for most of the way, towing a camper. Or the big slow pulls into and out of Kings Canyon Nat'l Park, where it's 25-30mph on twisty 2 lane at about 7% grade or better, for 30 minutes.....again, towing the camper and in the heat.
So it's at 276k now, still running strong. I replaced the oil pressure sender behind the dizzy, but that had no effect on the gauge, so I put the original back on.
I still haven't taken an oil pressure reading with a mechanical gauge, mainly because it's going to be a PIA to take the dizzy out, remove the sender, put the test gauge w/ hose in, and then take it all back apart in order to put it back to stock after the test.
Is there another test port somewhere? I was reading in the other current thread that there might be a sender on the oil filter housing? My truck has a factory engine oil cooler with it's big spacer block between the filter and the original filter housing, and 2 lines running to a huge cooler up in front of the a/c condensor. There is no sender in the oil filter area. There is one in the block, over about at the end of the starter, but I think that's a knock sensor, right?
So........what's causing the knock, and should I be concerned? The knock has never gotten any worse in the 50k we've put on it.
Should I pull the pan and take off all the rod caps and main caps and inspect bearings? Can I get the end-most main caps off? Should I replace the oil pump? If so, should I use an uprated one? More pressure version? More volume version? Brand of pump?
I always run synthetic 5w/30 and either an ACD filter, a K&N filter, or a NAPA WIX gold that is the bigger "industrial engine" version which is a big long filter.
If I do pop the pan off, what are the torque specs for the rods and mains?
Thanks!
Ever since buying our 'burb in 2004, with 225k on the original engine, the oil pressure has only readL
COLD: about a needle width past the 30psi mark during cold running, idle, or rev'd.
HOT: a needle with or so below the 30, idle and about on 30 hot at cruise speed (2,000rpm).
It's has always had a dull, *knock........knock.......knock..........knock* during initial cold start that goes away in about 1-2 seconds. Doesn't always do it cold, but usually. Might do it on a hot start, but that's pretty rare.
I've never trusted the gauge, figuring that if the oil pressure was really that low, it would have already grenaded, especially since we tow in the heat, and in the mountains with it. For example, 12hrs non-stop each way, to and from Grand Canyon, AZ to here in SoCal in triple digit heat for most of the way, towing a camper. Or the big slow pulls into and out of Kings Canyon Nat'l Park, where it's 25-30mph on twisty 2 lane at about 7% grade or better, for 30 minutes.....again, towing the camper and in the heat.
So it's at 276k now, still running strong. I replaced the oil pressure sender behind the dizzy, but that had no effect on the gauge, so I put the original back on.
I still haven't taken an oil pressure reading with a mechanical gauge, mainly because it's going to be a PIA to take the dizzy out, remove the sender, put the test gauge w/ hose in, and then take it all back apart in order to put it back to stock after the test.
Is there another test port somewhere? I was reading in the other current thread that there might be a sender on the oil filter housing? My truck has a factory engine oil cooler with it's big spacer block between the filter and the original filter housing, and 2 lines running to a huge cooler up in front of the a/c condensor. There is no sender in the oil filter area. There is one in the block, over about at the end of the starter, but I think that's a knock sensor, right?
So........what's causing the knock, and should I be concerned? The knock has never gotten any worse in the 50k we've put on it.
Should I pull the pan and take off all the rod caps and main caps and inspect bearings? Can I get the end-most main caps off? Should I replace the oil pump? If so, should I use an uprated one? More pressure version? More volume version? Brand of pump?
I always run synthetic 5w/30 and either an ACD filter, a K&N filter, or a NAPA WIX gold that is the bigger "industrial engine" version which is a big long filter.
If I do pop the pan off, what are the torque specs for the rods and mains?
Thanks!
Last edited:
