Do you need to bleed new lash adjusters for a Pentastar 3.6L?

[explorer2030]

I purchased a new set of Mopar lash adjusters for a 2015 Pentastar 3.6L, and notice that out of the package the plunger is rock hard, and they seem like they are fully extended. Is it necessary to release the oil pressure from these lash adjusters and partially depress the plungers so they are not installed fully extended, or are they designed in such a way that they would self bleed and shorten up to the correct length once the engine is running if they were too long when initially installed?

The service manual states that they should be at least partially filled with oil, but then in another section states to fill them with oil before installation. I don't see any mention of checking installed length, however, I have come across some general engine information that isn't Pentastar specific indicating that valves could be held open partially if the lash adjusters are not bled down and partially compressed prior to installation.

 

[Timmastertech]

The ones I have done the lifters came in a bag that had some oil in it so I installed them as they came out of the bag. If they are dry out of the package I would let them soak for a while in a container of oil

 

[explorer2030]

What do you think about this guys video talking about bleeding OHC lash adjusters? It sounds logical to install them in a compressed state if the plunger once extended cannot be retracted until the check ball that seals the internal oil chamber is depressed. My concern is why wouldn't this procedure be specified in detail in the service manual if it's so critical to prevent valve seating or other issues? Do the 3.6L lash adjusters work differently, and have the ability to self adjust to become shorter once they are extended?

 

[Timmastertech]

With spring pressure applied to the lifters the lifters will bleed to wherever they need to be as the engine cranks. Back when we were doing Gm 3.1/#.4 intake gaskets regularly we found that if you left the pushrods out for a long time the lifters would pump up and the engine would lose compression when you tried to start post repair so what we started doing was leaving the injector connector unplugged to crank the engine no fuel to build oil pressure and let the lifters go back to where they needed to be.

 

[explorer2030]

Here is a picture of one of the new lash adjusters in the bag. I cannot pull the plunger out or push it in, so they appear to be fully extended compared to what the old ones look like in the engine. You can confirm on this 3.6L engine, there is no issue with installing them like this fully extended and filled with oil?

 

[Timmastertech]

Here is a picture of one of the new lash adjusters in the bag. I cannot pull the plunger out or push it in, so they appear to be fully extended compared to what the old ones look like in the engine. You can confirm on this 3.6L engine, there is no issue with installing them like this fully extended and filled with oil?

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You should never be able to compress a lifter with your fingers, thats one of the tests we do for a failed lifter. Install and go, you will be fine

 

[paulo57509]

The Honda C27A used hydraulic tappets that would varnish up and no longer take up the clearances. Some just lived with the noise, some used Restore that was temporary at best. Others spent the time and $$$$ to replace them. Often the tappet bleeding procedure before installation was skipped due to ignorance or whatever.

"How come the engine is still !!&"*# noisy??!!"

HDEO quieted the tappets in mine but it took a l-o-n-g time.

 

[Yourhomiematt]

Just did this job on my 3.6 with the ESS, which has updated HLAs and rockers. I soaked everything in oil before assembly. Fired right up with a very slight tick(I assume it was the hlas pumping up) that went away in 5-6 seconds. I also used a healthy amount of assembly lube on the cam lobes and bearing surfaces

 

[explorer2030]

Just did this job on my 3.6 with the ESS, which has updated HLAs and rockers. I soaked everything in oil before assembly. Fired right up with a very slight tick(I assume it was the hlas pumping up) that went away in 5-6 seconds. I also used a healthy amount of assembly lube on the cam lobes and bearing surfaces

So you didn't manually collapse the lifter before installing it? IE push down on check ball with a small allen wrench through the hole in the end of the plunger and press plunger down slightly.

 

[Yourhomiematt]

So you didn't manually collapse the lifter before installing it? IE push down on check ball with a small allen wrench through the hole in the end of the plunger and press plunger down slightly.

The way I read it is the lifters self adjust almost instantly with oil pressure

 

[explorer2030]

The way I read it is the lifters self adjust almost instantly with oil pressure

I think the oil pressure would only cause the plunger to extend until the rocker meets the camshaft lobe, but what if they are already extended beyond this length when you install them? I would assume this would mean they act like a solid pivot point, and put additional force on the rocker arm causing the valve to partially open unless they can self bleed and collapse from the force of the valve spring. Did the ones you install look extended like the picture I posted of mine in the previous post?

 

[Yourhomiematt]

I think the oil pressure would only cause the plunger to extend until the rocker meets the camshaft lobe, but what if they are already extended beyond this length when you install them? I would assume this would mean they act like a solid pivot point, and put additional force on the rocker arm causing the valve to partially open unless they can self bleed and collapse from the force of the valve spring. Did the ones you install look extended like the picture I posted of mine in the previous post?

Yes and I too noted I couldn't compress them by hand

 

[explorer2030]

Yes and I too noted I couldn't compress them by hand

Did you notice that the rockers were pushing up on the cams at all when you tightened down the cam caps even with the cam in the neutral position? You had no other detrimental effects from installing them like this other than 5-6 seconds of ticking on initial startup?

 

[Yourhomiematt]

Did you notice that the rockers were pushing up on the cams at all when you tightened down the cam caps even with the cam in the neutral position? You had no other detrimental effects from installing them like this other than 5-6 seconds of ticking on initial startup?

Yes the Cam will be opening some valves when you tighten the caps. Tighten them evenly

 

[explorer2030]

I found some additional information in the cylinder head diagnosis section of the FSM, which indicates that the lash adjusters are designed to automatically bleed down and collapse with slow hand pressure. The new lash adjuster did not seem to collapse at all when pressing on the plunger with light hand/finger pressure, but it did collapse down a little bit when I clamped it hard between the base of my thumb and forefinger over about 30-40 seconds. It stays somewhat spongy once collapsed, so I am thinking that the valve springs should have no issue collapsing these if it's possible to do with hand pressure.