Impala Forums banner
1 - 7 of 7 Posts

·
Registered
Joined
·
4 Posts
Discussion Starter · #1 ·
Hello, this is my first post on here. I have been searching all over looking for answer and found none. I recently bought an ‘08 impala SS, and rebuilt the motor. I got everything done and started up and warmed up the car and when idling the low oil pressure light was coming on. I racked my brain to make sure that i did everything correctly when putting the motor together. I was checking to make sure i plugged everything in and underneath the motor on the oil pan there is a sensor unplugged and i cant remember if it was plugged in to begin with. I believe it is the oil level sensor. I replaced the oil pressure sensor when rebuilding the motor, so that should be fine. Im wondering if that sensor being unplugged could give me low oil pressure warning.
 

·
Registered
Joined
·
1,365 Posts
Did you R&R the screen filter under the oil pressure sensor?
Is the oil pressure sensor any good? They aren't a paragon of reliability.
 

·
Registered
Joined
·
1,365 Posts
Screwing a mechanical oil pressure gauge onto the engine to briefly test the actual oil pressure would be a good sanity check.

Those AFM screens are $9. It's not expensive enough to be worth the possibility that it doesn't come out clean for me to re-use one.

I assume you replaced the oil pump and pickup tube with a New Melling M355 or M10355 oil pump and a replacement pickup tube for the LS4 engines.
I also assume you replaced the secondary pressure relief valve and installed the updated oil pan gasket from the high oil consumption tech service bulletin.
The oil pump pickup tube O-ring and the over pressure bypass valve in the oil pump itself are common problem areas.
It's super easy to nick the pickup tube O-ring or pick the wrong one for your oil pump and the LS engines do have issues with both primary and secondary bypass valves.

The cam seal plate is another place you could be loosing a fair amount of oil internally.

Not trying to be offensive. I do not know you and your experience level so questions bear asking.
 

·
Registered
Joined
·
4 Posts
Discussion Starter · #5 ·
Screwing a mechanical oil pressure gauge onto the engine to briefly test the actual oil pressure would be a good sanity check.

Those AFM screens are $9. It's not expensive enough to be worth the possibility that it doesn't come out clean for me to re-use one.

I assume you replaced the oil pump and pickup tube with a New Melling M355 or M10355 oil pump and a replacement pickup tube for the LS4 engines.
I also assume you replaced the secondary pressure relief valve and installed the updated oil pan gasket from the high oil consumption tech service bulletin.
The oil pump pickup tube O-ring and the over pressure bypass valve in the oil pump itself are common problem areas.
It's super easy to nick the pickup tube O-ring or pick the wrong one for your oil pump and the LS engines do have issues with both primary and secondary bypass valves.

The cam seal plate is another place you could be loosing a fair amount of oil internally.

Not trying to be offensive. I do not know you and your experience level so questions bear asking.
I have figured out the issue and i feel stupid for this. Sooo… i had a new crank ordered for my motor and when i installed everything i installed the standard sized bearings, and everything went in perfect and I neglected to check bearing clearances (very bad idea). I called my machinist the other day to see what could be causing my issues, and he brought up the crankshaft being milled .010 under stock size. The crank came with a set of bearings but i had assumed that they were the same as the set of bearings that came in my overhaul kit. So now i know to always check my clearances no matter what. This was my first ever engine rebuild and it shows i guess… everything else turned out fine, just the issue with the bearings and i will be getting the car running tomorrow.
 

·
Registered
Joined
·
1,365 Posts
I have figured out the issue and i feel stupid for this. Sooo… i had a new crank ordered for my motor and when i installed everything i installed the standard sized bearings, and everything went in perfect and I neglected to check bearing clearances (very bad idea). I called my machinist the other day to see what could be causing my issues, and he brought up the crankshaft being milled .010 under stock size. The crank came with a set of bearings but i had assumed that they were the same as the set of bearings that came in my overhaul kit. So now i know to always check my clearances no matter what. This was my first ever engine rebuild and it shows i guess… everything else turned out fine, just the issue with the bearings and i will be getting the car running tomorrow.
That'll do it. Hopefully no glitter in the oil.

As I get older I get less worried about screwing up. More careful, but less worried about it when I discover one of my inevitable screwups when I'm doing something new.
No matter how you feel about screwing up. Just remember, you can't get a patent on it. Someone else has already screwed that up before you the exact same way.
 
  • Like
Reactions: sheila

·
Registered
Joined
·
4 Posts
Discussion Starter · #7 ·
That'll do it. Hopefully no glitter in the oil.

As I get older I get less worried about screwing up. More careful, but less worried about it when I discover one of my inevitable screwups when I'm doing something new.
No matter how you feel about screwing up. Just remember, you can't get a patent on it. Someone else has already screwed that up before you the exact same way.
Ill take it as a learning experience, lol! No sparkly oil this time, thank goodness
 
1 - 7 of 7 Posts
Top