Sudden drop in oil pressure @ idle
Thread Starter
On The Tree
Joined: Jun 2019
Posts: 148
Likes: 29
From: Atlanta, GA
Sudden drop in oil pressure @ idle Greetings, and thanks in advance.
Car is a heads/cam build a few years old. Forged bottom end, melling high volume oil pump. 5k on build and 65k on the car.
The following readings are from the stock gauge:
Ever since I have owned the car it idled at around 40psi hot and shot up to 60 even cruising at 2-3k. I always thought this was a little high but I never let it bother me.
Today I fired the car up and after letting it warm up I noticed the pressure at hot idle was 20-25psi. Hits ~40 cruising and 55-60 at WOT all the way up to 6k. This doesn't seem abnormal to me, the car pulls hard with no weird noises or anything. Normal amount of oil consumption it's always had and same little bit of blue smoke at WOT the car has always had.
Is there any reason to worry about this given that it's changed so drastically? The oil pressure still responds to throttle input like you'd expect it to and never drops below 20, it seems like basically what a stock LS1 reads. Am I reading too much into this with regard to trusting the stock gauge and sending unit? I come from the SBC world but I am not super familiar with these engines and I didn't build this car.
Car is a heads/cam build a few years old. Forged bottom end, melling high volume oil pump. 5k on build and 65k on the car.
The following readings are from the stock gauge:
Ever since I have owned the car it idled at around 40psi hot and shot up to 60 even cruising at 2-3k. I always thought this was a little high but I never let it bother me.
Today I fired the car up and after letting it warm up I noticed the pressure at hot idle was 20-25psi. Hits ~40 cruising and 55-60 at WOT all the way up to 6k. This doesn't seem abnormal to me, the car pulls hard with no weird noises or anything. Normal amount of oil consumption it's always had and same little bit of blue smoke at WOT the car has always had.
Is there any reason to worry about this given that it's changed so drastically? The oil pressure still responds to throttle input like you'd expect it to and never drops below 20, it seems like basically what a stock LS1 reads. Am I reading too much into this with regard to trusting the stock gauge and sending unit? I come from the SBC world but I am not super familiar with these engines and I didn't build this car.
TECH Senior Member
Joined: Jun 2016
Posts: 22,298
Likes: 3,619
From: Central Cal.
I wonder if the relief piston in the oil pump might be stuck where the bypass port is SLIGHTLY uncovered, thereby letting a little pressure bleed off.
It's the only thing I can think of that can happen suddenly.
It's the only thing I can think of that can happen suddenly.
Thread Starter
On The Tree
Joined: Jun 2019
Posts: 148
Likes: 29
From: Atlanta, GA
Same oil and filter I always have. I plan on draining the oil today to see how it looks, but the car is running fine.
