Had a rough day…

[Texarkana]

Hey all. I have a vehicle equipped with the 3800 Series III engine.

Back in Feb I installed split ratio rocker arms and an aftermarket intake insert, and since I was in there I decided to replace the plastic coolant elbows with aluminum ones. Since then I’ve had an annoying belt squeak I pulled my old elbows after they are prone to breaking off in the lower intake manifold. Turns out it did happen and I was leaking coolant onto my belt.

Took the tensioner off this morning and in the process of retrieving the broken piece of elbow it fell into the lower intake manifold coolant passage. I grabbed a LIM set and took it all apart. I was in a rush since I have to work tonight and wanted to catch a nap beforehand, and apparently I installed the block rail seals backwards. I didn’t find out until I watched a video of the LIM gasket install later. The GM Manual nor the piece of paper that came with the gaskets said they had to be installed in a certain direction. The pegs lined up with the block itself and I didn’t pay any attention to the old ones so I just slapped em on, applied RTV and bolted it all back together. I used black RTV on the 4 joints as I was supposed to.

The oil doesn’t appear to have coolant in it. I checked it by rubbing it between my fingers and it was slick, but it is synthetic. (Has 5500 miles on it). I also did a blot test by putting a good amount on a business card and slowly blotted it into the card. It fully absorbed into the card without leaving behind any residue.

I hoping someone can put my mind at ease and tell me this won’t cause any issues. I’m thinking bout tearing it all apart and re-doing it when I get home tomorrow morning.

I know the block rails have nothing to do with coolant leaking I’m just making sure this won’t cause issues down the road somewhere.

Topic

[dan]

if you mean block rail seal buy the seals that go between the cylinder heads on the block, seals essentially the lifter valley between the cylinder heads where the LIM meets the block right?

those two seals simply prevent oil from the lifter vally from seeping from the lifter vally down the side of the block, my suggestion to you is for a while keep an eye for any leaking oil down the side of the engine, i don’t know what you mean buy backwards, in fact a picture might help, but you may be ok… as long as its sealing you may be alright, but you won’t have coolant mixing with oil since if i am understanding you correctly all that does is prevent oil in the lifter valley from leaking down the side of the block…

When i was just starting out as a mechanic i did a LIM gasket job on a 3100SIF, and there are no gaskets for that part of the engine, you just put sealant there, and my grandpa had some old… stuff, told me it was still good, so i put it on and it crumbled apart and oil started to leak, but that is all that will leak really slowly, so i had to fix it again.

[Texarkana]

Yep they’re shaped like an upside down L. The flange was supposed to go inside the block, not outside. It doesn’t appear to be leaking so I should be ok.

[Glenn]

Hi Texarkana, I did exactly the same thing years ago to my 3800 series III. I later discovered there are two makes/ styles of block rail seals, some with the tabs and some without. The ones with the tabs have rounded recessed holes in the block the tabs fit into. If you have an adequate seal already, as AceofSpades says, you should be fine. Mine lasted for 6 years until I had to go after the heads due to a stuck valve. Just keep an eye on it for escaping oil….

[Texarkana]

I’ve checked after every drive, none so far. Hopefully it’ll hold. Thank god these things require RTV or I’d be digging into the engine again.

[Texarkana]

Welp I feel like an idiot. After setting down the LIM I quickly yanked it off to apply more RTV just to be safe, didn’t check the gasket to see if they had shifted any. Now I’ve got an oil sheen in my overflow tank and my dipstick and exhaust smells sweet.

I’ll be re-doing the job on Saturday. Anyone have any bright ideas on how to flush the cooling system at home with household products so I can save some money after buying 2 gasket sets? 😳

[Texarkana]

Yay! Good ole check engine light.

Just got a check engine code tonight. PO128. The coolant isn’t reaching temperature fast enough. Ran diagnostics through Torque.

MID:$61 TID:S1a
Heated Catalyst Monitor Bank 1
Min: 4,177 Max: 1
Current: 6,751

MID:$a7 TID:$0b
Misfire on Cylinder 6, 1 count over the last 10 drive cycles.

MID:$c8 TID:$30
No identifying info, so I’m not sure what this one is.
Min: 5,641.7 Max 409.6
Current: 2893.1

Not going to be driving until I put in new gasket Saturday. Looks like I get to drive the Dakota.

[Texarkana]

Good news, not coolant leak. I boogered the thermostat when I removed it replacing the intake gasket which is what threw the code. Replaced the thermostat and the code hasn’t come back. The misfire was from the O2 wire touching the #6 plug wire.

Bad news is I have a leak from the block rail. A very small one but a leak is a leak. Right where the rear head, LIM and block meet there is a very slow drip making it’s way down the block under the head and hitting the exhaust manifold.

I’m going to be replacing my water pump and rear valve cover on monday. Bearing is squealing something fierce and I put the wrong alternator bolt in the wrong spot and cracked my valve cover back in Feb when I installed the rocker arms and intake insert.

Plan is to clean the leak up with degreaser, spray the area leaking down with brake clean to remove any oil or dirt and use a popsicle stick to smudge some RTV into the gap that is dripping oil and leave it to sit over night, hopefully it’ll seal the small gap up and stop my leak.

[Texarkana]

Great… More issues. Hopefully someone can shed some light on this.

First things first. For some unknown reason the #3 cylinder O-Ring melted and got stuck in my LIM. It took so much force to remove the fuel rail that the injector pintle cap broke loose from the injector and my ride is stranded until tomorrow until I the GB Reman arrives in the mail.

I kept tearing it all down, got the rear valve cover replaced and started on the water pump. I assume one of the water pump bolts runs into an oil passage because one bolt had an oil coating on it. This same bolt ran into the coolant passage because coolant poured out of it.

After all was said and done the coolant that came out had a nice rainbow oil sheen on it. It either came from the bolt, me using the same funnel for oil changes that I use for filling coolant or something else entirely. I also noticed the oil that pools on the LIM bolts on these engines had straight water in it. There was a clear bead of water sitting right in the middle of this pool of oil covering the LIM bolt which gives me hope that it’s just condensation and not coolant.

So I’m planning on running a coolant pressure test when it’s all said and done just to ensure I don’t have anything else going on, do you guys think it would be a good idea to test the coolant for hydrocarbons to make sure I don’t have a blown head?

[Author]

Replies