Hydraulic lifters Stuck? Bad?

[dom14]

Hey Guys,

I'm wandering whether the hydraulic lifters stuck like this(not moving at all) indicates they are bad beyond any use. Out of 12 lifters in this cylinder head(RB30 Nissan), only two moves. That's why I am not sure whether they are actually bad or may be in a stuck position due to some reason, but not necessarily bad??!!!

https://www.youtube.com/watch?v=5V_V...ature=youtu.be

I know if I blow a bit of compressed air into a lifter through the oil receiving hole, it get momentarily stuck.
But, I did no such thing with these lifters. They belong to the original old cylinder head that came with my RB30.
I have another cylinder head which goes onto the engine block today has only two stuck lifters like this.
My idea is to swap two from the old one, and funnily enough only two moving lifters that I can see on the old cylinder head.

Any of your opinions, explanations will be appreciated.

Thanx in advance.

Dom

P.S. The cylinder head, rockers, lifters, etc are pretty clean looking 'cos it runs on LPG all the time. So, I don't think it's carbon build up, but not all that sure. However water got into oil by blown head gasket, so I don't know whether the water-oil mixture can stuff up the lifters like this.

[dom14]

I pulled apart one of the stuck lifters and cleaned it with break cleaner, part by part and put back it back together.
It's moving(the bouncing action) fine now(full range of movement).
When I inject a bit of compressed air through the hole, it hardens & get stuck again, but gradually start to move again.

Any "hydraulic lifter specialists" out there that can decode that behaviour and tell me whether the lifters that behave like that are shot
or not??

Thanx

[dom14]

This is how much they cost. But, I prefer not to fix it if it ain't broken.

Nissan RB30 LIFTERS RB30T Skyline R31 VL holden commodore turbo | eBay

[Winnie]

You're talking to yourself again Dom

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[dom14]

You're talking to yourself again Dom

Sent from my SM-G935F using Tapatalk

Pretty much.,
But, it's good. I'm documenting something here that may be useful to somebody someday.

[dom14]

These are the photos of the hydraulic lifter that I was(apparently) able to "revive" by cleaning with WD40 & high pressure air gun.

https://photos.app.goo.gl/IvHuy0WqoNBrR1bx2
https://photos.app.goo.gl/15jCDGWyV2yzW5XG2
https://photos.app.goo.gl/Ec9lmsEbcgJL8hed2
https://photos.app.goo.gl/p6EvP3Sxv8wZN0Kh2

[dom14]

I have come up with two or three theories to decide when they are shot.

1)When oil residue clogs up the internal oil passages(which can be corrected by tearing it apart and cleaning with WD40 & high pressure air gun, I believe)

2)The internal moving pistons(two of them) are worn and the gap between the bore and piston has increased to the point of leaking too much oil and reducing the hydraulic effect. - This is a scenario where they are shot for good

3)The spring at the bottom of it has lost it's gas and lost tension and has gone soft - I reckon it's not common. I think the spring lasts bit longer than we think. But, I'm not 100% sure as I don't have a brand new one to tear apart and assess the spring tension.

[dom14]

These are lifter rebuild videos. DIY stuff.
Basically, mechanically not much goes wrong with these hydraulic lifters unless they run dry or something.
Rebuilding them is pretty much a good clean up job.

I reckon my method of using compressed air with WD40 is better and quicker than any of the methods of these videos.

One thing is fairly certain in most situations of stuck valve lifters though. That is they can be rebuilt by spend less than five minutes on each lifter.

I'm going to pull each lifter out individually tomorrow and rebuild(clean) them one by one.

https://www.youtube.com/watch?v=LXRP78lEXag


https://www.youtube.com/watch?v=6Mvr7peX7Ns
https://www.youtube.com/watch?v=Hi3S17dzHCQ
https://www.youtube.com/watch?v=8J8RS75k4ns
https://www.youtube.com/watch?v=DN7ExcCYg3E


https://www.youtube.com/watch?v=ZpSuwEI0Q8M

https://www.youtube.com/watch?v=ySf0r8GGMOY

https://www.youtube.com/watch?v=lgLIwYGya9Y

[dom14]

This thread explains the function of hydraulic lifters.

https://www.bimmerforums.com/forum/s...raulic-lifters

I quoted below passage from it where it answers my OP question about lifters being stuck hard.
Basically this says that the hard(stuck) lifters are good & the moving(squishy) ones are bad(means need cleaning to remove gunk from the check ball)

"let me sure I got it right, the ones I tested that have have the spring motion (squishy ones) are considered good? this is the end result I want to see on all of them when done cleaning?

One guy on this board bought some brand new lifters and saying they won't budge at all when new, that's why I'm so confused ..."


"The squishy lifters need attention. Good ones pump up with oil and become virtually solid. Squishy ones aren't completely filled with oil which means they aren't sealing properly. If you take one apart you'll see what's going on inside. Basically there's a one-way check valve (a little spring loaded ball bearing) that should let oil into the lifter but not let it out. If for some reason the check valve isn't able to close fully it allows oil to leak out and the lifter won't pump up. Usually it's just an accumulation of varnish or a piece of dirt preventing a full seal and cleaning will restore proper function."

[dom14]

Signs and Symptoms of a Bad Lifter Flat Tappet

https://itstillruns.com/signs-sympto...-10045359.html