Oil Pressure

[wjburken]

I dropped the oil pan and the o-ring on the pickup tube was brittle. So hard it broke in two while trying to remove it very gently. Obviously an issue, but should I replace the dump valve above the oil filter while I have it apart? I read that sometimes the spring gets weak.

Personally, I would. You already have the pan off, it’s right there and it’s not that expensive of a part, I would do it.

 

[tjoyce81]

My 2007 5.3l Tahoe w/225k has been suffering from fluctuating oil pressure, I replaced the screen and sending unit, no change. The pressure is very low (10psi or less) on startup, it climbs when engine RPMs are above about 1,000, but then quickly drops back at idle, I wonder if this could be the pressure relief valve, in the oil pan, you mention above. I did not know that existed. Could it be that sludge is causing the valve to stick? I am considering dumping a quart of ATF into the motor, running it at idle for 15-20 minutes, then changing oil to see if it removes sludge and frees the valve. A whole lot easier than dropping the pan. Thoughts?


Appreciate the response. I have seen several Utube videos that illustrate a way to replace the o-ring (and oil pump) without dropping the pan. I assume you can not inspect, clean or modify the pressure relief valve unless you drop the pan. Correct?

Sorry about the late reply. YES - your issue IS the pressure relief valve IN the pan. There are 2 ways to fix it. You can remove it and install a plug. OR replace it. Either way the pan has to be dropped.
Not as hard as it looks. Also, it is not the oil pump OR the O-ring. BUT when you have the pan down, it makes sense to just replace the O-ring...

 

[tjoyce81]

Here is the plug kit I installed. http://www.improvedracing.com/oil-p...uct_search&utm_source=googleproductsearchusen

 

[tjoyce81]

Here is the part number for the valve 12608835

 

[donjetman]

I put a relief valve shield under the relief valve when I did mine - shield# 12639759 - $8, relief valve# 12608835 - $14, pickup tube o-ring Felpro# 72401 or GM# 12584922 - $9.
View media item 28091View media item 28092View media item 28093

 

[daves07 tahoe]

Went ahead and changed the o-ring on the pickup tube and SUCCESS! Oil pressure is at 40PSI on startup and never drops below 30PSI at warm idle. Hits ~45 PSI at higher engine RPMs. This is compared to wildly fluctuating pressure before, down to near zero. One tip is that I did not drop the front diff altogether. Just unbolted it from the axle on the passenger side, removed all four bolts holding the diff then lowered it on a jack for support. Still a lot of work, hope I never have to do that again.

 

[daves07 tahoe]

Here is the part number for the valve 12608835

Thx. Also learned that Chevy has an additional part (oil diverter) that slips over the valve to push oil back down into the pan. This is a fix for high oil consumption.

 

[BG1988]

I dropped the oil pan and the o-ring on the pickup tube was brittle. So hard it broke in two while trying to remove it very gently. Obviously an issue, but should I replace the dump valve above the oil filter while I have it apart? I read that sometimes the spring gets weak.

replace any parts that need it like the screen and sensor