Low Oil Pressure at Idle When Warm

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

OP
OP
A

Austen Leach

Member
Joined
Jan 17, 2020
Posts
38
Reaction score
34
Lot of auto parts stores rent them for free, sans deposit which you get back
None of my local parts stores rent oil pressure testers. The only pressure gauges they have are compression and an electronic fuel pressure gauge
 

Tonyv__

Full Access Member
Joined
Apr 18, 2018
Posts
2,504
Reaction score
5,004
Location
Bucks county PA
I thought you had swapped it out. The other way would be to view data from scan tool and compare to dash and then of course a mechanical gauge. As for the o-ring, yes, over-filling would submerge the o-ring and eliminate starvation if it was pinched or rotten.

I might try this to see if my o ring is bad.. however after testing. Should I drain it back down to 6qts? I’ve always heard overfilling was bad for the engine but I don’t actually have any evidence to back that up
 

swathdiver

Full Access Member
Joined
May 18, 2017
Posts
19,104
Reaction score
25,038
Location
Treasure Coast, Florida
I might try this to see if my o ring is bad.. however after testing. Should I drain it back down to 6qts? I’ve always heard overfilling was bad for the engine but I don’t actually have any evidence to back that up

Well, I thought so too with these engines but a fella on here was down on his luck and kept his over-filled for two years until he could afford to get it fixed.
 

SnowDrifter

Full Access Member
Joined
Sep 5, 2016
Posts
2,402
Reaction score
2,577
Location
Washington. The desert side not the Starbucks side
I might try this to see if my o ring is bad.. however after testing. Should I drain it back down to 6qts? I’ve always heard overfilling was bad for the engine but I don’t actually have any evidence to back that up
Overfilling is bad when the crankshaft dips into the oil and whips it into a foam.

You can tell by running your rig for a few mins and quickly pulling the dipstick out to inspect while running.

FWIW I run 7 quarts in mine. I run the long filter but it doesn't displace an appreciable amount. No aeration issues

Edit: brain dump. Not sure about front or rear seals. IIRC they're primarily to guard against oil spash vs oil butting up against it. I suppose it could worsen a leak if there's a pool of oil sitting against the things, but then again, if it doesn't seal there, I can't see it sealing in general. And besides those points, if your running oil level is that high, your engine is trying to make a nice whipped topping out of your oil.
 

Tonyv__

Full Access Member
Joined
Apr 18, 2018
Posts
2,504
Reaction score
5,004
Location
Bucks county PA
Do NOT run overfilled it causes the oil to foam which is BAD.

You can run maybe 1/2 quart high but 8-9 quarts is way to much.
Are you saying I shouldn’t even over fill just to test the o ring theory? Or I shouldn’t overfill and leave it in the engine for a long period of time.
 

avalonandl

Full Access Member
Joined
Apr 6, 2019
Posts
2,200
Reaction score
2,628
Location
Troy, MICH & Naples, FL
Are you saying I shouldn’t even over fill just to test the o ring theory? Or I shouldn’t overfill and leave it in the engine for a long period of time.

You can overfill it to test it but drain back down before driving.

Oil that has foam in it is actaually air bubbles and will not provide consistent oil coverage on bearings.
 
OP
OP
A

Austen Leach

Member
Joined
Jan 17, 2020
Posts
38
Reaction score
34
I’ve got a little update/addition to this issue. Yesterday I drove to Arlington to pick up a 2/4 drop kit for my cousin’s truck. I checked my oil before I left and it was right in the middle of the crosshatching. I ran about 85mph the entire way there and back. Got in the Tahoe the next morning and started it up to run and grab some coffee and the dash read “check oil level”. Pulled the stick and nothing on it. I topped off the oil back to about 3/4 up on the crosshatching and crawled under the truck to ensure I didn’t have a massive leak somewhere. I have a tiny tiny rear main leak but nothing ever touches the ground and nothing is blown back on the transmission or anything. Also after I went to the coffee shop and went out and started the Tahoe I had a decent smoke cloud come out from the exhaust. I was in the shop for about 35 minutes and my windows are tinted extremely dark so I couldn’t really see the color of the smoke but I’m not losing any water and my oil doesn’t look milky or anything
 
Top