My 5.3 Engine swap

[humvee]

Hummer went back in for that engine oil leak. We've changed the main seal twice now with no luck.

Something else is up. Can it be that the engine is mounted a tad bit too forward, and the bolts near the seal are at their limit, causing a tiny gap under engine acceleration strain?

Shooting in the dark, fishing for theories.


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[4speedfunk]

Smoke coming from the dipstick tube, and leaking seals points to a crankcase pressure issue. I would triple-check the PCV system again.

 

[humvee]

Thank you, will double check. I feel at this point the seal would be shot because of all the leaking. There is no escaping another tranny drop.


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[humvee]

Its been a while and thought I’d update the build. My 3 swap was plagued with problems and now I’m in the process of redoing everything that was done poorly before.

Previous mechanic had broken the oil dip tube, and welded this to make it work. They found that he had used glue to secure it, all burnt up and was causing a leak.

With the rebuilt tranny in place, I decided to go with all new bower cooler lines, separated the whole distance to and from the cooler.

This engine mount adapter has 6k miles on it. Previous mechanic didn’t trim properly and therefore the driver side exhaust manifold was resting on it. Motor wouldn’t articulate when revved, fixed.

Proper fuel lines and fittings, routed them away from the exhaust manifold where they were resting previously.

Installed oem exhaust manifolds that point in the correct direction, reworked the custom downpipes and deleted the cats.

Redtop battery installed with some trimming to the battery housing lid.

Used the cooler that came with the tranny as a power steering oil cooler.

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[Mr_Rich]

A lot of "iffy" work there. One thing I learned when swapping an LS engine and removing the oil pan is that the engine loses prime. New O-rings are required on the pickup tube and then you pump two quarts of oil through the oil galley access port on the driver's side of the block. Service manual info. When I worked on my LS project I bought the $200 priming tool. Cheap investment for a $7K engine. I'm wondering if your engine was started bypassing the oil priming procedure. CaseyS remarked that the real work is all the detail and nick-and-dime stuff on these projects. Isn't that the truth? Dropping an engine into the bay is the easy part.

 

[humvee]

We put in the new o ring, but Im pretty sure they just put in the oil from the top filler.

Truck has been started & driven since, what do you think the damage is?

I sent it back because there still is a motor oil leak near the rear crank seal. This issue has spanned the entire build and I’m still unable to fix it. Replaced that seal 4 times to date.


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[5gn-h3t]

As others have said, sounds like a crankcase pressure issue. Excess pressure would cause oil leaks, seal failures, and some of the other problems you have mentioned. Re-check the PCV system and perform a leak down test.

 

[Mr_Rich]

We put in the new o ring, but Im pretty sure they just put in the oil from the top filler.

Truck has been started & driven since, what do you think the damage is?



I sent it back because there still is a motor oil leak near the rear crank seal. This issue has spanned the entire build and I’m still unable to fix it. Replaced that seal 4 times to date.

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What it would mean is that there wasn't immediate oil pressure when the engine was started and it ran with dry bearings until the oil circulated. I wish the H3/ H3T's had an oil pressure gauge and not an idiot light. When I did the swap in my car I unplugged the coil pack connections and turned the engine over and watched the gauge. I saw that needle climb and knew I was ready to hook everything up. No problem after that. As for the seal there is a procedure that involves steps including the installation of the oil pan and rear cover. Could be shortcuts are the problem. There are a lot of little tricks with these LS engines that were never issues with small block Chevy engines.

 

[speedy]

There are a lot of little tricks with these LS engines that were never issues with small block Chevy engines.

I sent it back because there still is a motor oil leak near the rear crank seal. This issue has spanned the entire build and I’m still unable to fix it. Replaced that seal 4 times to date.

Are they reusing the flex plate bolts? They require thread sealant. Oil can leak past the threads mimicking a seal leak.
Good luck i despise oil leaks

 

[Mr_Rich]

Are they reusing the flex plate bolts? They require thread sealant. Oil can leak past the threads mimicking a seal leak.
Good luck i despise oil leaks

You sure about that? I'm positive both the end of the crank and the torque converter have blind holes which would not require anything except maybe threadlocker. I checked the end of the crank on my LS; blind holes, not through.

 

[speedy]

Yes
www.autoserviceprofessional.com/article/94984/engine-sealing-tips-how-to-avoid-problems-from-annoying-leaks-to-devastating-dam
There's plenty of mention on the LS boards if you search

I never mentioned anything about torque converters:sigh:

Maybe this is part of the problem

TSB 05-06-01-034J: Engine Oil Leak at Rear Cover Assembly Area
(Engine Block Porosity RTV Repair Procedure) - (Nov 12, 2009)

 

[humvee]

Thanks guys, I’ll spend some time with the head mechanic and discuss process.
I’ll ask for a leak down test and take it from there.


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[Mr_Rich]

Yes
www.autoserviceprofessional.com/article/94984/engine-sealing-tips-how-to-avoid-problems-from-annoying-leaks-to-devastating-dam
There's plenty of mention on the LS boards if you search

I never mentioned anything about torque converters:sigh:

Maybe this is part of the problem

TSB 05-06-01-034J: Engine Oil Leak at Rear Cover Assembly Area
(Engine Block Porosity RTV Repair Procedure) - (Nov 12, 2009)

You said "flex plate bolts". To me that means the plate that connects the torque converter to the end of the crank. Now are you calling the cover on the back part of the LS engine a "flex plate"? Then I was confused...

That TSB is interesting.

 

[JPaul]

I can confirm the bolt holes for the flex plate to crank bolts are through holes and not blind, I just had my engine all apart for the rebuild. I made sure to use locktite on the threads when I put the new bolts in (used ARP bolts) so that seals them up as well. If they were reused it's entirely possible they could be leaking oil past.

There is also that TSB where the rear cover plate could not be sealing correctly due to porosity in the block which I think is what speedy linked)

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[Mr_Rich]

I can confirm the bolt holes for the flex plate to crank bolts are through holes and not blind, I just had my engine all apart for the rebuild. I made sure to use locktite on the threads when I put the new bolts in (used ARP bolts) so that seals them up as well. If they were reused it's entirely possible they could be leaking oil past.

There is also that TSB where the rear cover plate could not be sealing correctly due to porosity in the block which I think is what speedy linked)

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It looks like it's a detail I'm wised up on. Since I had a manual trans and wasn't dealing with a flexplate I never had an issue. After further research it looks the car cranks have through holes and the truck cranks have a wider sealing area and possibly they are the cranks with blind holes although I couldn't say for sure either.

 

[JPaul]

Makes sense, I think the H3's and other lighter trucks use the car blocks vs standard pickups/vans that use truck blocks. Seems the aluminum 5.3 we use is a car block with a truck intake, cam, and accessories. I noticed when buying the ARP bolts for the flexplate to torque converter the ones I bought were for cars using the 4l60e while there was another set for trucks using the 4l60e, the main difference being the cars only use 3 bolts while the trucks use 6.

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[speedy]

Again no mention of torque converters or converter bolts:banghead:

Now are you calling the cover on the back part of the LS engine a "flex plate"? Then I was confused...

"Seriously" :giggle:


With that being said i'm done here. I'm not going to split hairs with you and muddy up someone else thread with trivial B.S.

Humvee good luck with your oil leak.

 

[humvee]

Thanks, I sent this through to him.
He came back earlier and said that its the Valve cover gasket and deactivation solenoid gasket causing the oil leak.

This is a visual confirmation without unbolting any of the parts.


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[humvee]

I need to buy the gasket for the Cylinder Deactivation Solenoid.
Haven't been able to find the gasket set separately for the H3, they sell them separately for the Yukon, Sierra, Silverado and Escalade.

Anyone here ever came across it?

 

[JPaul]

The covers are the same for all GM Gen IV 5.3's, it's not model dependant. The only difference is if you have AFM/DOD or not. None of the H3's came with AFM/DOD so they use that gasket set. Any engine that has the AFM/DOD will use the gaskets like the one you have pictured above.

 

[humvee]

The only difference is if you have AFM/DOD or not. None of the H3's came with AFM/DOD

Thanks, what do you think of this? Its on rock auto for the Colorado but not the H3. Amrg found it.

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[JPaul]

Yep, that's the one. You have the non-AFM/DOD valley cover, right? There should also be 8 1" diameter or so circle shaped gaskets that fit into the underside of the cover to block off the oil bosses, unless it's a gen 3 block which won't have them. You don't really want to re-use them as any leaking will result in low oil pressure. It leaks internally though at least so you won't lose oil. Some guys will tap the bosses for 1/8" NPT plugs or just straight 1/4" set screws and block them off that way as well to be sure they won't leak. But you really only need to do that if you're running higher than normal oil pressure and/or racing.

 

[JPaul]

This is the right set from felpro: http://www.fme-cat.com/overlays/par...=MS 96169&partType=Intake Manifold Gasket Set

I found that when I ordered my head gasket set I had to find the right one by searching for a 2010 H3, for some reason the 2008 and I think 2009 H3's tend to come up with sets for the Gen 3 engines, but ours is a Gen 4 and uses several different gaskets, one of which is the valley cover.

 

[humvee]

Thank you! Yes I have the gen IV. This is very helpful.


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[zebra]

simply subscribing so i can find this later. if our 3.7 has a bad head gasket (and i can reach Shawn Townsend regarding his OS), a LH8 might finally be our future.