txbandit44
TYF Newbie
- Joined
- Jan 2, 2022
- Posts
- 14
- Reaction score
- 3
Back story
Bought the truck 1-1-22 145,017 miles 5400 hrs no leaks no oil pressure issues IRRC it was around 30 at idle and over 40 on the highway. I do not remember how fast it built its full pressure. it was 74deg in Fort Worth when I bought the truck and by the time I drove it the 45 miles home the temp dropped 40 deg and stayed in the low 30's high 20's for a few days. in this time the truck developed a oil leak on the rear of the engine and the master cyl started gurgling. Took the rig back to the dealer and they replaced the brake booster/ mast cyl and the oil cooler gasket. Picked up the truck drive it home and left town for a month. Wife drove the truck while I was out and the leak returned. She didn't tell me because she had another set of wheels and knew I needed to focus on the task at hand. So she parked it in the garage. I get back found the leak but don't have faith in the dealers ability to diag or repair the truck, so as usual Im going to do it. I found the oil cooler is leaking still and they used a Felpro gasket. Replace it with a MAHLE brand and the oil cooler stopped leaking, but I found that's not the only thing leaking. Back to no confidence in their diag skills (for more reasons than this) I start crawling all over it with a inspection cam.
FF to today 149,000 miles
Nothing is visually leaking up top and the rear main seal is dry as is the flex plate. So I have narrowed the leak down to 3 sources. Oil pan gasket left rear corner, rear main seal cover gasket or loose cover bolt, or some how I have a leak on the VLOM plate that is making its way down the left side of the block with out showing signs on the outside. I did find that the front 2 VLOM bolts finger tight so I snugged those down. I think driving it on those cold days created a pressure leak. Only solutions are to live with it, drop the pan, pull the intake, and or pull the trans for the RMS. All are doable just trying to keep the While Your In There costs at bay.
Now, I think I have a oil pressure issue but maybe not? Its hard to tell because the information I get is all over the place. I feel like most of the information out there is generalized to the LS platform and may or may not apply to my L94. While looking for the leak I convinced myself that its a pressure related leak. So that has had me constantly looking at the OP gauge. Which brings us to the point of what's going to be torn apart next.
The issues I think I have are low oil pressure and slow to build oil pressure. I tried to gather info as scientifically as I can so here what I got.
FYI I'm using a HF oil pressure gauge and I'm pulling from the front drivers side port behind the PS pump.
500 miles on this Valvoline High mileage 5w-30 Dexos PF48E filter
COLD START 60 deg day
Crank Start
After 15-20 min drive
Shut off and restart 2min later
Added 2.5 qts but didnt test until the next day
COLD start on 2.5 qts over filled
Drove for 15-20 min
That's all I had time for the wife needed the truck back. It runs great has a bit of a miss here and there but nothing I would consider an issue at 149k .
Based on all this I'm not sure if I have a issue or not. I don't know the history of the the motor. I know its original. Nothing stands out like it was abused. I did change the plugs and wires 1000 miles ago and found 2 wires loose and #6 plug was loose. Did find the screen has been removed or replaced. They left the old one the VLOM plate. The Oil dip stick is golden to dark almost black, I'm sure who ever had it before me used whatever the house oil was at the lube centers. Other than that its pretty clean.
Not knowing what good / great oil pressure is in a well maintained L94 with 149k on it's hard to say if I have an issue or not. Adding 2.5 qts didn't yield the improvements in pressure I expected so I cant say the pick up seal is bad. Pressures seem to be in the general norm for LS engines
I am waiting on the correct adapter m16x2.0 to 1/8-27 so I can check pressure at the sensor and a filter sandwich so I can check the both at the same time and compare.
Does anyone out there know what The L94 should have for pressure at the pump and at the sensor?
Does it look like I need to consider replacing the oil pump when I drop the pan? IF so that's where the While your in there monster starts eating my wallet.
Long read I know thanks for hanging in there.
Bought the truck 1-1-22 145,017 miles 5400 hrs no leaks no oil pressure issues IRRC it was around 30 at idle and over 40 on the highway. I do not remember how fast it built its full pressure. it was 74deg in Fort Worth when I bought the truck and by the time I drove it the 45 miles home the temp dropped 40 deg and stayed in the low 30's high 20's for a few days. in this time the truck developed a oil leak on the rear of the engine and the master cyl started gurgling. Took the rig back to the dealer and they replaced the brake booster/ mast cyl and the oil cooler gasket. Picked up the truck drive it home and left town for a month. Wife drove the truck while I was out and the leak returned. She didn't tell me because she had another set of wheels and knew I needed to focus on the task at hand. So she parked it in the garage. I get back found the leak but don't have faith in the dealers ability to diag or repair the truck, so as usual Im going to do it. I found the oil cooler is leaking still and they used a Felpro gasket. Replace it with a MAHLE brand and the oil cooler stopped leaking, but I found that's not the only thing leaking. Back to no confidence in their diag skills (for more reasons than this) I start crawling all over it with a inspection cam.
FF to today 149,000 miles
Nothing is visually leaking up top and the rear main seal is dry as is the flex plate. So I have narrowed the leak down to 3 sources. Oil pan gasket left rear corner, rear main seal cover gasket or loose cover bolt, or some how I have a leak on the VLOM plate that is making its way down the left side of the block with out showing signs on the outside. I did find that the front 2 VLOM bolts finger tight so I snugged those down. I think driving it on those cold days created a pressure leak. Only solutions are to live with it, drop the pan, pull the intake, and or pull the trans for the RMS. All are doable just trying to keep the While Your In There costs at bay.
Now, I think I have a oil pressure issue but maybe not? Its hard to tell because the information I get is all over the place. I feel like most of the information out there is generalized to the LS platform and may or may not apply to my L94. While looking for the leak I convinced myself that its a pressure related leak. So that has had me constantly looking at the OP gauge. Which brings us to the point of what's going to be torn apart next.
The issues I think I have are low oil pressure and slow to build oil pressure. I tried to gather info as scientifically as I can so here what I got.
FYI I'm using a HF oil pressure gauge and I'm pulling from the front drivers side port behind the PS pump.
500 miles on this Valvoline High mileage 5w-30 Dexos PF48E filter
COLD START 60 deg day
Crank Start
| RPM | Mech press | Dash pressure | Mech time to max | Mechanical delay before pressure rise | Dash delay before pressure rise | Dash time to max |
1400 | 60LB | 0lb | 2 SEC | NONE | 3 sec | 20 sec |
1200 | 57lb | Rising past 20 | ||||
1000 | 56lb | 38lb | ||||
| 700 IDLE | 52lb with bounce | 38 steady |
After 15-20 min drive
| RPM | Mech press | Dash pressure |
| 700 idle | 35lb | 20lb |
1200 | 45lb | 30lb |
2000 | 60Lb | 38lb |
Shut off and restart 2min later
| RPM | Mech press | Dash pressure | Mech time to max | Mechanical delay before pressure rise | Dash delay before pressure rise | Dash time to max |
1400 | 50LB | 0lb | 2 SEC | NONE | 4 sec | 24 sec |
1200 | 45lb | Rising past 10 | ||||
1000 | 40lb | 15lb | ||||
| 700 IDLE | 35lb with bounce | 20 steady |
Added 2.5 qts but didnt test until the next day
COLD start on 2.5 qts over filled
| RPM | Mech press | Dash pressure | Mech time to max | Mechanical delay before pressure rise | Dash delay before pressure rise | Dash time to max |
1400 | 58lb | 0lb | 2 SEC | NONE | 3 sec | 17sec |
1200 | 56lb | Rising past 20 | ||||
1000 | 56lb | 15lb | ||||
| 700 IDLE | 52lb with bounce | 41 steady |
Drove for 15-20 min
| RPM | Mech press | Dash pressure |
| 700 idle | 30 bouncing | 20lb |
1200 | 45lb | 22lb |
2000 | 50lb | 25lb |
That's all I had time for the wife needed the truck back. It runs great has a bit of a miss here and there but nothing I would consider an issue at 149k .
Based on all this I'm not sure if I have a issue or not. I don't know the history of the the motor. I know its original. Nothing stands out like it was abused. I did change the plugs and wires 1000 miles ago and found 2 wires loose and #6 plug was loose. Did find the screen has been removed or replaced. They left the old one the VLOM plate. The Oil dip stick is golden to dark almost black, I'm sure who ever had it before me used whatever the house oil was at the lube centers. Other than that its pretty clean.
Not knowing what good / great oil pressure is in a well maintained L94 with 149k on it's hard to say if I have an issue or not. Adding 2.5 qts didn't yield the improvements in pressure I expected so I cant say the pick up seal is bad. Pressures seem to be in the general norm for LS engines
I am waiting on the correct adapter m16x2.0 to 1/8-27 so I can check pressure at the sensor and a filter sandwich so I can check the both at the same time and compare.
Does anyone out there know what The L94 should have for pressure at the pump and at the sensor?
Does it look like I need to consider replacing the oil pump when I drop the pan? IF so that's where the While your in there monster starts eating my wallet.
Long read I know thanks for hanging in there.
