This was the pan I bought.
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L18 8.1L swap resource thread
- Thread starter Larry
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Looking at the GM parts catalog as of this morning the only part number they show for an 8.1 oil pan is the 12574833 which I can confirm is discontinued.
I looked across the platforms too. Same number comes up under truck or SUV. Also looked by year and the same number comes up for 2001 up to 2007.
By what I can tell, all early numbers that might have had the oil level sensor superceded to this one number.
As far as one showing for an Avalanche but not for a suburban, there applications are off because an Avalanche is the same thing as a Suburban under the skin. It's the same either way.
The most recent GM part number directly crosses to the Spectra part number GMP75a. So that shows me the Spectra should cover all the GMT800 trucks/SUVs.
I looked across the platforms too. Same number comes up under truck or SUV. Also looked by year and the same number comes up for 2001 up to 2007.
By what I can tell, all early numbers that might have had the oil level sensor superceded to this one number.
As far as one showing for an Avalanche but not for a suburban, there applications are off because an Avalanche is the same thing as a Suburban under the skin. It's the same either way.
The most recent GM part number directly crosses to the Spectra part number GMP75a. So that shows me the Spectra should cover all the GMT800 trucks/SUVs.
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There were a few different pan part numbers and quite a few if you figure in industrial and marine engines. But, as far as the small light trucks (Silverado, G-van and Workhorse chassis) there were two pans that I know of that later superseded to one part number. One had the provision for the oil level sensor and the other was cast over. When they stopped using the oil level sensor in production vehicles the service replacement part number changed to a 12574833, which did not have an oil level sensor hole but there was a cast plug that could be knocked out to add one if needed. The interesting thing is there are two versions of the 12574833 pan without the oil level sensor where they are pretty much identical but the passenger’s side of the pan on the later one has a sharp vertical edge instead of being more rounded. Not sure if GM had more than one supplier of these or if their tool broke and they had to redesign the passenger’s side, which it kind of looks like it as there are crude cast marks on the later pan on the passengers side.
Just like the GM Service Replacement oil pan, the Spectra Premium GMP75A does not have the oil level sensor hole but can be added if needed. This pan fits everything. The fact Suburban is missing is an obvious oversight on their part.
12574833 2003 8.1 in the K10. The pan on my 2001 Silverado is identical to this one other than it does have an oil level sensor
12574833 2008/09 8.1 in the Suburban. Notice how much sharper the edge is on the passengers side
K10
Suburban
Just like the GM Service Replacement oil pan, the Spectra Premium GMP75A does not have the oil level sensor hole but can be added if needed. This pan fits everything. The fact Suburban is missing is an obvious oversight on their part.
12574833 2003 8.1 in the K10. The pan on my 2001 Silverado is identical to this one other than it does have an oil level sensor
12574833 2008/09 8.1 in the Suburban. Notice how much sharper the edge is on the passengers side
K10
Suburban
Good information, Larry. I was just noticing there were 2 different designs with the "rounded edge" and "hangover edge" and couldn't find a separate part number, so it answers that question. You can find pictures of "hangovers" with the sensor, too (one below supposedly from 2002), so who knows what transitions happened. I'm actually finding more pans using the interchange number 311-00893 than the GM part numbers.
In every picture I've seen of GMP75A it does have the sensor hole and it seems to be a copy of the "hangover edge" design. Unfortunately even suppliers showing stock seem to not have it.
In every picture I've seen of GMP75A it does have the sensor hole and it seems to be a copy of the "hangover edge" design. Unfortunately even suppliers showing stock seem to not have it.
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Good information, Larry. I was just noticing there were 2 different designs with the "rounded edge" and "hangover edge" and couldn't find a separate part number, so it answers that question. You can find pictures of "hangovers" with the sensor, too (one below supposedly from 2002), so who knows what transitions happened. I'm actually finding more pans using the interchange number 311-00893 than the GM part numbers.
In every picture I've seen of GMP75A it does have the sensor hole and it seems to be a copy of the "hangover edge" design. Unfortunately even suppliers showing stock seem to not have it.
View attachment 335544
You’re actually seeing the provision, not the actual hole. This is the hymen to knock out if you need the level sensor
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No. Why do you want an oil level sensor anyway? They are just one more thing to go wrong with oil leaks and another sensor to fail
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Mostly because I want all factory parts and functions in place. I've driven hundreds of thousands of miles with oil level sensors and never had one fail or cause a leak. The one on my 5.3 has alerted me to a loose oil filter before, though.
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If you say so...
You've driven hundreds of thousand of miles but I work for a company that built and warrantied a few hundred thousand vehicles with these engines and would beg to differ as to how great these sensors are
. I certainly wouldn't go out of my way to add this particular sensor and there is a reason why GM discontinued using an oil level sensor with in a few years after it was introduced
Do you have a part number for the S-shaped oil fill tube? The straight tube blocks use of the 2003+ throttle body. Since my harness is a 2003 and I have both throttle bodies available, I would like to use the 2003+ version. Is it possible to pull the tube out of the intake manifold without messing stuff up?Yes, the following part numbers are for the later design engine cover with the s-shaped oil fill tube. Glad you brought that up.
2003-2007 Engine cover/oil fill
12574560 Engine Cover
12567370 Engine Cover Ball Stud
12562957 Engine Cover Bracket
12562958 x2 Engine Cover Bracket Stud
2000-2002 Engine cover/oil fill
12560199 Engine Cover
12562957 Engine Cover Bracket
12562958 x2 Engine Cover Bracket Stud
(2000-2002) 12560199 on left, (2003-2007) 12574560 on right
Good catch buddy!
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Ya, it will pop out just fine. Just pull the bolt out and start wiggling it back and forth. The later S-shaped fill tube is 12581140
It looks like the valve cover changed between '02 and '03 to accommodate the change from the older 580 coils (LS1 style) to the newer 581 coils (LS2 style).
The early cover is 12570483 and the later cover is 12570556. The coil connectors are different, but that difference is accounted for by the harness mounted the valve cover.
The early cover is 12570483 and the later cover is 12570556. The coil connectors are different, but that difference is accounted for by the harness mounted the valve cover.
What did they change on the coils?
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There are actually 3 8.1L valve covers that I know of. The first is the early black one for the AC Delco D580 Delphi coil packs then there is another black valve cover as well as a bare aluminum for the later AC Delco D581 Mitsubishi coil packs.
Top covers – Later Mitsubishi Electronics Coils: AC Delco D581
Bottom cover – Earlier Delphi Coils: AC Delco D580
Speaking of throttle bodies, have you guys ever had IAC issues? Long story short I'm still chasing down the passenger side miss as it seems to be getting worse. Idle is terrible coupled with another issue of a cylinder loading up and exhaust popping.
In the next couple days I'll be doing a leak down test and hooking up a buddies scanner to watch the live data.
In the next couple days I'll be doing a leak down test and hooking up a buddies scanner to watch the live data.
Got the new tube and it clears the newer throttle fine. Instead of bolting to the boss right behind the tube , it grabs the closest fuel rail studs. S-shaped is plastic, seals with an O-ring and takes the larger LS-sized oil fill cap. Straight pipe is steel and is glued to the manifold.
Where did you find that fill tube? I can’t find any.
Does it fit with the factory cover?
I ordered from Tasca parts. They took weeks to get it here due to "special order" (which I think applies to most of the parts they list). There were several GM parts dealers showing they can get 12581140, but nothing on places like eBay, Summit, Amazon, etc.
No. The 01-02 cover hits this tube. The 03+ cover is cut away in this area. I'm planning on modifying my '02 cover to make it work. Doesn't seem worth the hassle/expense of getting the later cover.
Larry covered that here, but it was in regards to clearing the manual throttle body, not the later TBW throttle body.
https://ck5.com/forums/threads/l18-8-1l-swap-resource-thread.308019/#post-3292850
