jerflash

ya i read an artical about a company who sells a modified rear engine cover that stops oil from leaking out of a plug in the back of ls6 blocks only

i dont rememebr what mag i saw it in but im thinking im having this problem with my new ls1 block and want to fix it

thanks if anyone can help me

joe

Beast96Z

iTrader: (21)

There is a hole in the back that has a plunger type plug in it. I'm sure this is what you are refering to. I just installed one the other day and the fit was so tight that the o-ring had to be sealed. I haven't heard of any leaking from there, but I guess it is possible.

Lesrace82

iTrader: (8)

How about just tapping this hole, and putting a threaded plug int there?

Beast96Z

iTrader: (21)

Well, I don't know exactlly what it is for, but the plug looks like a dumbell of some sorts. It has a head on one end, then a straight then bar, then another head with a o-ring around it. I don't think one threaded plug would allow it to do what it is supposed to be doing, although I have no clue what it does.

Brains

iTrader: (7)

That's what diverts oil down to the pan, and through the oil filter. Its gotta be there

pekkaz

Yes otherwise you'd do an oil filter bypass mod

BTW, if you order a new GM plug it should be the revised version which will not move out the hole

jerflash

ya i was a luck guy who got an ls6 in my car stock but that took a sh*t because of crappy lifters and i picked this motor up for a killer deal and i found out about this problem after the motor was already in the car

i think this is my probelm because when i hit the gas crusin in 4th gear the oil pressure drops 5 psi then starts to climb back up

hey Beast do you know the part number?

the oil problem is nothing that is peventing oiling to any of the parts i dont think so i will change it when i change my clutch

thanks alot guys

joe

LOnSLO

iTrader: (15)

I work at the shop that makes the rear covers you are talking about. It's Lamar Walden's in Atlanta. Have seen plenty of motors burned up due to the plug slipping out the back.

james99ws6

iTrader: (3)

are these ls6 blocks only or does the LS1 have the same problem?

jerflash

its only the ls1 block
i had an ls6 block and did not have the problem but now have a ls1

rodent

iTrader: (1)

I just did a thread looking for the correct part number for this.

How can these slip out if the rear cover is bolted over this plug???

jerflash

how much does the cover go for?
but if i get the new plug do i need the cover??

LOnSLO

iTrader: (15)

The rear cover doesn't come in contact with the back of the plug.

LOnSLO

iTrader: (15)

Call 770-449-0315 and ask for Rob. The rear cover needs machining to accept the plug.

rodent

iTrader: (1)

I just purchased the plug today and GM has changed the part number plus it looks different too. I wonder if this will help with the problem mentioned above. There's more plastic behind the o-ring resulting in a total seal even if the plug backs out.

I attached the picture showing both pieces.

Brown = old
white = new

12558340 (old part number)
12573460 (new part number)

BTW- The new plug fits in the block and sits flush so the stock rear cover fits over with no problems. No machine work has to be done, and I see no need for a special cover with the new designed plug.

james99ws6

iTrader: (3)

what happens when the plug wears or comes out? Can this soak your clutch with oil?

jerflash

no it cant soak your clutch because its covered by the rear cover and you stilll have the crank seal to get past

thanks alot rodent
big help man

rodent

iTrader: (1)

I would think the oil just goes back to the oil pan since the cover behind this plug is sealed but you would be losing oil pressure. Sounds more like a the seal that goes around the crankshaft if your clutch is getting soaked with oil.

Sure!
Just putting my engine together and I'm glad I ran across this post since I was going to re-use my old plug. Glad I got the new style.

axer

I am getting a new plug and I have a question. What end goes in
first? My plug had the rounded end facing the back of the block, and
the flat side (with the o-ring) installed first. The GM service manual
shows the rounded end installed first, and the o-ring on the rounded
end. This is the opposite of what my plug looks like!
Thanks!

pekkaz

O-ring end closest to the rear cover. Otherwise some of the pressure will bleed out of the oiling rails.