Chevy LS engine oil pickup O ring replacement on 4x4 trucks

Joined
Dec 31, 2017
Messages
15,066
Location
SE British Columbia, Canada
I've been doing some research for replacing the O ring on the oil pickup assembly where it bolts to the block on a Chevy truck equipped with a LS engine. This O ring is mentioned several time in Bitog threads.

The procedure is complicated by the presence of the front axle on a 4x4 truck. Basically, to do this, you need to lower the front axle to get clearance to remove the oil pan to get access to the O ring. I've looked at a lot of You Tube videos and the following video in my opinion is the most clear one.

The work can be done in your driveway or on a hoist. I have access to a rental hoist and would prefer to go that way if I do it. Here is the address for the video.



My local GM dealer wanted the equivalent of over $1,400 US dollars to do the work. I suppose an Indie mechanic can do it cheaper.

At 3:58 they start removing the bolts on the axle. At 14:52 they get the pan loose. At 19:10 he removes the pesky O ring. There are several sections of high speed video in between. Enjoy

Any other tips are most welcome.
 
Last edited:
Here is the actual estimate from the dealer in CDN dollars. Multiply by 0.7 for US dollars.

9288D86F-1408-4E0A-A2C0-AA669ACA3A14.jpeg
0C919DBE-7717-42EC-9D09-5BAEBA120A64.jpeg
 
All looks good. If the pan is out, and if you do not have an oil cooler, I like replacing the factory oil cooler delete plate with one of these.


Every LS I have without an oil cooler the factory block off plate is leaking -- I replace the gasket and it seems to leak again. The ICT Billet plate with the O-Ring do not leak for me.
 
I did that on my awd Yukon when the pan gasket started dripping. Was a pain of a job because of the front axle but a wife constantly nagging about a driveway getting "ruined" by some drops of oil is even more painful so it was worth it. Changed the pickup tube o ring and wire brushed some varnish off in there.
 
Make sure the O-Ring is orange like the one in the video; that'll mean it's made out of silicone to last longer and remain pliable.
It is very possible it is of silicone construction, however, colors and sizing also are based upon the shape of the pickup tube fitting whether the oring is fitting into a beveled groove or not. There'll usually be instructions with the O-ring... if not I know new Melling pumps always come with a diagram to tell you what o-ring to use. If I can find it I'll post it.
 
It is very possible it is of silicone construction, however, colors and sizing also are based upon the shape of the pickup tube fitting whether the oring is fitting into a beveled groove or not. There'll usually be instructions with the O-ring... if not I know new Melling pumps always come with a diagram to tell you what o-ring to use. If I can find it I'll post it.
The O-ring that came off in the video was blue. The new one that went on is orange. I wouldn't use a black one if at all possible. Black usually means Nitrile rubber. And the brand of the one in the video is not Melling; it's Mahle.
 
The O-ring that came off in the video was blue. The new one that went on is orange. I wouldn't use a black one if at all possible. Black usually means Nitrile rubber. And the brand of the one in the video is not Melling; it's Mahle.
I would say disregard color/construction and just follow what the Oring mfg. states per the intended application. You may have some pickup tubes that will require a new black one.
 
I've been doing some research for replacing the O ring on the oil pickup assembly where it bolts to the block on a Chevy truck equipped with a LS engine. This O ring is mentioned several time in Bitog threads.

The procedure is complicated by the presence of the front axle on a 4x4 truck. Basically, to do this, you need to lower the front axle to get clearance to remove the oil pan to get access to the O ring. I've looked at a lot of You Tube videos and the following video in my opinion is the most clear one.

The work can be done in your driveway or on a hoist. I have access to a rental hoist and would prefer to go that way if I do it. Here is the address for the video.



My local GM dealer wanted the equivalent of over $1,400 US dollars to do the work. I suppose an Indie mechanic can do it cheaper.

At 3:58 they start removing the bolts on the axle. At 14:52 they get the pan loose. At 19:10 he removes the pesky O ring. There are several sections of high speed video in between. Enjoy

Any other tips are most welcome.

What was your oil pressure down to and how many miles? I have 240k miles on my 05 Silverado and the oil pressure has remained a steady 33-34 psi hot idle the last couple of years.
I'd read that the reason for the o ring failing was it getting nicked at the factory. If that was the case you would think it would have started to show symptoms by 18 years and 240k miles wouldn't it?
 
The usual symptoms of an O-Ring that needs replacement is low oil pressure upon startup (20-30 PSI) and an oil pressure reading that DOES NOT increase much with RPM until the engine is warmed up. The failure that occurs is that the O-Ring gets hard and shrinks over time. With some heat in the engine/oil, the O-Ring swells back up and your pressure starts to look normal.

I know, I know, they say 8psi per 1,000 RPM on small-block Chevy's... but any Gen III LS I've ever driven, with a half-way decent shape motor has been 40-45+ PSI on cold start and 35/38-40 PSI at hot idle on a 5W-30. Maybe a little bit more on 15W-40. Gen III do not normally sit at 15-20-25 PSI.

Also, yes the oil pressure gauges are not NASA exact and do have some (maybe a lot) of margin for error, however, you get used to what they should look like regardless of their accuracy.
 
What was your oil pressure down to and how many miles? I have 240k miles on my 05 Silverado and the oil pressure has remained a steady 33-34 psi hot idle the last couple of years.
I'd read that the reason for the o ring failing was it getting nicked at the factory. If that was the case you would think it would have started to show symptoms by 18 years and 240k miles wouldn't it?
So the way it grabbed by attention was that I did a posting this past winter when is was super cold and commented on a start at -4 F. I commented that the oil pressure came up to 25 psi and stayed there until the engine warmed to 160 F and then my idling pressure rose to about 38 psi and stayed there until the engine was at 210 F. The 38 psi is normal for my truck which had Pennzoil Platinum Euro 5W40 in it.

A few folks contributed that they thought the O ring might be brittle in the cold and wasn't sealing properly. My normal highway oil pressure is 42 psi at 60 mph and goes up just a bit when the revs go up to say, 3500 rpm while passing at 70 mph.

Now, I'm not 100% convinced the O ring is the issue but it is plausible. Coincidently I have 240,000 miles as well, and it is a 2008 6.0 so very similar to yours.

The other theory is that my oil pressure sensor is at the top of the engine and the cold oil had to be pumped through the filter and the gallery to the top of the engine. If the bypass did not open, the sensor might have not seen the full pressure that it lost in travelling to the sensor. Apparently though, no one else noticed this behavior on their engine. A few reported they just see a pressure higher than 42 psi until the oil warms up.

I'm currently checking the oil pressure on trips, looking for any other issues before I commit to the O ring and pan gasket replacement. I am however OK with erroring on the caution given it has 240,000 miles. I drive through the mountains a lot including areas with no cell service. I plan to try run this truck to 300,000 miles.
 
Last edited:
I've been doing some research for replacing the O ring on the oil pickup assembly where it bolts to the block on a Chevy truck equipped with a LS engine. This O ring is mentioned several time in Bitog threads.

The procedure is complicated by the presence of the front axle on a 4x4 truck. Basically, to do this, you need to lower the front axle to get clearance to remove the oil pan to get access to the O ring. I've looked at a lot of You Tube videos and the following video in my opinion is the most clear one.

The work can be done in your driveway or on a hoist. I have access to a rental hoist and would prefer to go that way if I do it. Here is the address for the video.



My local GM dealer wanted the equivalent of over $1,400 US dollars to do the work. I suppose an Indie mechanic can do it cheaper.

At 3:58 they start removing the bolts on the axle. At 14:52 they get the pan loose. At 19:10 he removes the pesky O ring. There are several sections of high speed video in between. Enjoy

Any other tips are most welcome.

I did the o-ring on our 07 Yukon Denali w/6.2L 4 yrs and 45k miles ago with: Felpro 72401 = GM 12584922 - $9 amazon
 
A few reported they just see a pressure higher than 42 psi until the oil warms up.
'05 Suburban in my sig, 220k on the clock. Has new oil pump, cam plate and pickup tube O-Ring as of 10/2022. 55-58 psi at cold start with 5W-30 and ACDelco PF61E.

'05 Tahoe in my sig, about 175k-ish on the motor, with 4 year old O-Ring OE cam plate and OE oil pump, 55 psi at cold start with 5W/10W-30/15W-40 mix and WIX 51522.

Both filters are the long filters.
 
While it is a bit involved of a job, I don't think you can go wrong with it. I'd be pretty inclined to think this is what is causing your pressure reading fluctuations.

Two other areas on an LS that I would say are worth investing time in, if you have it torn down to these areas of course, is the camshaft plate and then the oil galley plug ("barbell") behind the rear timing cover.

The cam retainer plate has an integrated O-Ring gasket/seal that flattens out with time. This seal keeps the lifter galleries fed with oil.

The oil galley plug/"barbell" sits in a channel behind the rear cover. There is a O-Ring on it that (can you guess what I'm about to say?!?),... shrinks. Very easy to change. ICT Billet and probably others make a billet aluminum one that is double O-Ring'd as an upgrade. I have never used one as the ACDelco OE plastic ones are easy to come by and inexpensive. Additionally, I have heard that some folks have a hard time installing the billet one as it is a very tight fit. Figured if the OE plastic one is good for 200k/15yr on a lot of motors (if not going longer), then thats good enough for me.

Of course, both of these services are "if" you're into the engine that far. On my 2005 Suburban, with 200k on the clock, I noticed it had noisy lifters at cold start until pressure pumped up. Then around 215k I started to notice low pressure during a run cycle until it was fully warmed. That is what prompted me to just tear into her and go new O-Ring and cam plate. I DID not replace the barbell/oil galley plug on the rear... I wasn't pulling the trans.

Since I was already that far into pulling the cam gear, I also threw a new timing chain and Melling oil pump.

Today, the 'Burban is quiet on a cold start and the lifers are quiet. She's noisy like every high-mileage LS, but oiling and top-end related... very quiet.

Just figured I'd share my experience.
 
I did the o-ring on our 07 Yukon Denali w/6.2L 4 yrs and 45k miles ago with: Felpro 72401 = GM 12584922 - $9 amazon
Rock auto matches these product numbers but their GM O rings are packs of 5.
I also ran a 2008 6.0 and a 2010 4.8 ( my son’s truck ) and a 2010 5.3. All the engines have matching parts numbers on the O rings.
 
While it is a bit involved of a job, I don't think you can go wrong with it. I'd be pretty inclined to think this is what is causing your pressure reading fluctuations.

Two other areas on an LS that I would say are worth investing time in, if you have it torn down to these areas of course, is the camshaft plate and then the oil galley plug ("barbell") behind the rear timing cover.

The cam retainer plate has an integrated O-Ring gasket/seal that flattens out with time. This seal keeps the lifter galleries fed with oil.

The oil galley plug/"barbell" sits in a channel behind the rear cover. There is a O-Ring on it that (can you guess what I'm about to say?!?),... shrinks. Very easy to change. ICT Billet and probably others make a billet aluminum one that is double O-Ring'd as an upgrade. I have never used one as the ACDelco OE plastic ones are easy to come by and inexpensive. Additionally, I have heard that some folks have a hard time installing the billet one as it is a very tight fit. Figured if the OE plastic one is good for 200k/15yr on a lot of motors (if not going longer), then thats good enough for me.

Of course, both of these services are "if" you're into the engine that far. On my 2005 Suburban, with 200k on the clock, I noticed it had noisy lifters at cold start until pressure pumped up. Then around 215k I started to notice low pressure during a run cycle until it was fully warmed. That is what prompted me to just tear into her and go new O-Ring and cam plate. I DID not replace the barbell/oil galley plug on the rear... I wasn't pulling the trans.

Since I was already that far into pulling the cam gear, I also threw a new timing chain and Melling oil pump.

Today, the 'Burban is quiet on a cold start and the lifers are quiet. She's noisy like every high-mileage LS, but oiling and top-end related... very quiet.

Just figured I'd share my experience.
If I was doing any tranny work or replacing the rear seal I think I would do the barbell.
 
Here are the torques from the Haynes manual. I believe all the LS engines use the same torques at least up to 2010 which is the age limit on the manual. If you think that’s incorrect please let us know.


6E114E74-5402-4401-A5A1-6FBC8C4AF849.jpeg
92705C39-973E-4C90-9F9F-67E0E831EB69.jpeg
 
Back
Top