OP low cold, OP normal warm - LS1TECH - Camaro and Firebird Forum Discussion

Generation IV Internal Engine 2005-2014 LS2 | LS3 | LS7 | L92 | LS9

OP low cold, OP normal warm

Thread Tools Search this Thread
Old 03-17-2017, 02:14 PM   #1
Teching In
Thread Starter
Join Date: Feb 2017
Posts: 7
Default OP low cold, OP normal warm

TBSS LS2. OP was normal 40psi cold/warm. Melling high volume, high pressure pump.

Heard a noise one day, very faint only on light accel 2.2k~ rpm. Did cylinder balance test, it was #6 piston. I pulled pan, polished the crank journal, made sure it specd out right before slapping a new bearing set in for that one rod only.

Took the rest of the caps off to ensure the other bearings were fine. All was good. Replaced motor mounts while I was in there.

Truck runs fine, pulls hard, no noise. But ever since I completed this a month or so ago, my OP has been acting strangely.

Typically, idle and cold, it's around 25psi. Drive it around for a while, at idle it's 40psi. Sometimes I drive it around for a while and it still goes back down to 25psi.

I re-used my pickup tube o-ring as it was only 1 year old.

Think that may be the case here? Kinda weird the only things I touched were rod caps, the one bearing half, and the pickup o-ring that could've affected pressure...

LS2Swapped92 is offline   Reply With Quote
Old 03-27-2017, 12:27 PM   #2
TECH Addict
iTrader: (15)
Mercier's Avatar
Join Date: Jun 2014
Location: Baton Rouge, LA
Posts: 2,383

Consider some trash/gunk in the oil pump bypass. Slight possibility that slightly undersized the journal causing a tiny internal oil leak(high clearance) and the clearance tightens up when it warms up. If you suspect the o-ring or similar, drive it hard, shut it down, and immediately check dipstick for air bubbles(aeration).

Last edited by Mercier; 03-27-2017 at 07:53 PM.
Mercier is offline   Reply With Quote

Related Topics
Thread Thread Starter Forum Replies Last Post
Oil pump o ring and oil pan drop ElQueFør Generation III Internal Engine 14 10-03-2017 05:03 PM
Low oil pressure in newer build (416 LS3) epix Generation IV Internal Engine 8 08-21-2017 09:24 PM
Wont start when warm. ? pwrtrip75 PCM Diagnostics & Tuning 22 08-03-2017 11:56 PM
2010 5.3 low oil pressure-help please redriver racing Generation IV Internal Engine 43 05-25-2017 04:29 AM
Need help guys , i'm out of ideas chevellepst Generation III External Engine 5 06-04-2016 08:59 AM

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

All times are GMT -5. The time now is 09:02 PM.

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
  • Ask a Question
    Get answers from community experts
Question Title:
Your question will be posted in: