Lq9 Low oil pressure when engine is cold
Oct 24, 2014 | 10:33 PM
#12
Or it could be trash in the oil pressure sensor screen. Use a pick and take the screen out of the sensor. My second guess would be sludge in the pickup tube. Run a can of seafoam in the oil for a few hundred miles, or a quart of trans fluid. It will clean all the sludge and gunk out.
Oct 28, 2014 | 01:31 PM
#14
TECH Enthusiast
Joined: Sep 2009
Posts: 670
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From: NC
I would say run some trans fluid through it first for a couple hundred miles and see if you can clean some sludge out of it before you swap the sensor. If the oil comes out really sludgy then you will need to address that issue before you keep putting parts on it.
Oct 28, 2014 | 06:06 PM
#15
Thread Starter
On The Tree
Joined: May 2012
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Motor is clean inside I already ran half a quart of atf along with pennzoil yellow bottle for about 500 miles then dumped it. Oil came out clean. My buddy owned motor before me and he used Amsoil and maintained engine.
When I turn the key on with engine offmy New oil pressure gauge will read 10psi. I can unhook pressure unit and it goes to 0 so I know gauge cluster is not bad.
My old sensor did same thing sometimes it would read 20 with engine not running and slowly go to zero.
I just swapped this engine in about 1000 miles ago. Never remember seeing gauge do this before. Is there a ground linked to sending unit that could be causing the gauge to read that it has pressure even when it's off?
When I turn the key on with engine offmy New oil pressure gauge will read 10psi. I can unhook pressure unit and it goes to 0 so I know gauge cluster is not bad.
My old sensor did same thing sometimes it would read 20 with engine not running and slowly go to zero.
I just swapped this engine in about 1000 miles ago. Never remember seeing gauge do this before. Is there a ground linked to sending unit that could be causing the gauge to read that it has pressure even when it's off?
Nov 7, 2014 | 07:33 PM
#18
Thread Starter
On The Tree
Joined: May 2012
Posts: 116
Likes: 0
Hooked up mechanical gauge and same exact results. 30psi cold, eventually gets up to about 37 psi when engine is warm (20+ Minutes idle) rev it up to 2k and it goes to 50psi.
when cold I can rev it up to 2k and it will go up about 2 psi.
What could be causing this?
Bad o ring?
Cracked pickup tube?
This engine was previously boosted for about 10k only revved to 6k and was maintained
when cold I can rev it up to 2k and it will go up about 2 psi.
What could be causing this?
Bad o ring?
Cracked pickup tube?
This engine was previously boosted for about 10k only revved to 6k and was maintained
Nov 9, 2014 | 07:17 PM
#19
Who knows.
Weak pump, o-ring maybe, too hard to say. Your cold start oil pressure sound lower but it should be okay, it's not that low and when warm it's great. Run it till it dies or take it apart.
Weak pump, o-ring maybe, too hard to say. Your cold start oil pressure sound lower but it should be okay, it's not that low and when warm it's great. Run it till it dies or take it apart.
