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89-W-Body-Regal

Need some professional help about replacing intake manifold gaskets?

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I am thinking about replacing the intake manifold gaskets on my 2.8 V6 Multi Port Injection In my 89 Regal. I was just wondering, If I remove the rocker arms and push rods, when I put them all back in the corrrect holes seating in the hydraulic lifters will I need to adjust the rocker arms or just torque them to specs? Service Information said to torque them down. But didn’t mention anything about having to adjust the rockers to a specific position. If the rocker arms only need to be torqued seating on the rods will I not face anything like engine ticking or engine knock after wards? The engine has currently 56,000 miles but it’s due for intake manifold replacements. I don’t want to have to replace my engine because I didn’t put the push rods or valve in correctly. I wanna do it correct so I don’t have to take it apart again and adjust them. I know if I put all the rods back in the correct order they came out it should be ok right?

Edited by 89-W-Body-Regal

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They just get torqued down. There is no adjustment. Put both the rockers and the pushrods back in the exact same places they came out of (the 60 degrees use two different length pushrods). 

Do you need to replace the intake gaskets because they're leaking? 50k miles is pretty low to have those gaskets leak, especially on a Gen 2 motor, which don't really tend to have issues.

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Forgive me if this is too elemenary but you have to rotate the engine and torque them down on the bottom of the lobes at 0 lift.

You probably figured that out but it would suck if your valvetrain became a whirling self destructive disaster if you didn't.

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The issue on the 2.8 and the 3.1 LH0 I believe is that the intake bolts themselves don't have any (blue) Loctite on them, and the torque spec is a little inadequate.  So what ends up happening is when subjected to heating and cooling cycles, they leak along the horizontal plane of the gasket, but don't actually suffer any visible gasket failure.  The force exerted by the intake bolts simply isn't good enough to keep everything tight and sealed during the extreme thermal transients experienced during at shutdown.  (shutdown = peak temperatures, as there is no coolant circulation).

The job was done twice on my (LH0) 3.1 MPFI after leaking LIMs, at around 50k mi (by previous owner), and then again at around 90k mi.  The gasket itself that I removed was in pristine condition (and probably could have been safely re-used, although I ended up replacing with a brand new Fel-Pro), and applying a higher torque value and using blue Loctite (or Permatex Blue actually) has resolved the issue for the past ~70k mi.  If you buy a brand new bolt kit, they often come pre-coated with a blue thread locking material, but I just re-used the existing hardware (give the bolts a good clean in solvent/brake cleaner to remove residual oil!).  

Edited by pitzel

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On 2/20/2019 at 3:40 PM, digitaloutsider said:

They just get torqued down. There is no adjustment. Put both the rockers and the pushrods back in the exact same places they came out of (the 60 degrees use two different length pushrods). 

Do you need to replace the intake gaskets because they're leaking? 50k miles is pretty low to have those gaskets leak, especially on a Gen 2 motor, which don't really tend to have issues.

Yes. I was told I might have a intake leak because every time I start my engine at cold starts it feels like it’s gonna shut off on me. This only happens at 60 to higher degrees of climate weather. 

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On 2/22/2019 at 9:02 AM, Imp558 said:

Forgive me if this is too elemenary but you have to rotate the engine and torque them down on the bottom of the lobes at 0 lift.

You probably figured that out but it would suck if your valvetrain became a whirling self destructive disaster if you didn't.

What do you mean rotate the engine and torque down the bottom of the lobes at 0 lift.

Edited by 89-W-Body-Regal

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38 minutes ago, digitaloutsider said:

I don't see why you would need to rotate the engine to put the valve in a specific place, that's generally to accommodate adjustable rockers.

I have never done it on any 60 degree or 3800.

The factory information for my vehicle said I would have to only rotate the engine if I reconditioned or changed the valve lifters. I am not going to do that. I am just going to replace the gasket than torque them down to specs. I like this engine is self adjusting because it’s not like the older Chevys that you had to adjust when running,

Edited by 89-W-Body-Regal

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In a small block Chevy with adjustable rockers and/or solid lifters, yes sure. There is no lash to be set on a 60 Degree or 3800 with hydraulic lifters.  It doesn't matter where on the cam lobe the lifter is sitting. 

Pull up the repair procedure from eSI yourself, it's not part of the process.

Edit: Also, to OP, rocker arm bolts are TTY and should be replaced.

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Lower intake end gasket started leaking oil on my 92 Cutlass 3.1, so I am going to replace the gasket some time in the near future.

I am going to buy one of the push rod removal tools, so I don't have to unbolt the rockers.

Edited by snippits

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44 minutes ago, snippits said:

Lower intake end gasket started leaking oil on my 92 Cutlass 3.1, so I am going to replace the gasket some time in the near future.

I am going to buy one of the push rod removal tools, so I don't have to unbolt the rockers.

If you have a torque wrench and know the torque specs, unbolting the rockers is no big deal.  

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2 hours ago, pitzel said:

If you have a torque wrench and know the torque specs, unbolting the rockers is no big deal.  

Yeah that’s what I am going to do. I seen in videos just remove the push rods, make sure they are all correct firing order as removed and label them. Than just lay and swing the rockers without removing them if you can. I just bought a torque wrench too. Factory info says torque rocker arms bolts to 18ft pounds on 2.8 and 3.1. Than you are good to go to put in

Edited by 89-W-Body-Regal

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