Hydraulic lifter Collapse? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Arl37 · 01-01-2019, 09:02 PM

I went to adjust the valve lash on my SBC 350 today. One of the rockers required much more tightening to eliminate the clicking than the others. In other words, the amount of exposed thread above the adjusting nut was much greater than on the other rocker studs.
I wonder what could have caused this.
I would appreciate you thoughts on this.

**davischevy** · 01-01-2019, 09:04 PM

There is a good chance the stud has pulled out of the head.

Arl37 · 01-01-2019, 09:31 PM

Thanks for your comment, However, heads are Edelbrock E Street and i don't think the rocker studs screw directly into the heads. There is a plate for each cylinder on the head with a rocker stud on each side of the plate.. There is a bolt on each side of the plate that secures the plate to the head.

I will check this tomorrow.

Something's not right

Mike C · 01-01-2019, 09:49 PM

The plates should be push rod guide plates that are required with aluminum heads, so you are correct that it would not pull out. Flat tappet cam? I'd be worried you wiped a lobe.

**AussieinNC** · 01-01-2019, 10:33 PM

The lifter has most likely either collapsed or has junk in its sealing valve...or, the lobe has died and lost its lift ramp....
Either way, flat lifter cam or roller lifter cam, its to to pull the manifold and distributor...and remove the offending lifter...

Roller cam...if the roller on the bottom of the lifter is intact, the internals of the lifter is faulty and the lifter needs replaced. If the roller is locked up or missing...you will have to pull the cam and replace all lifters and the cam.

Flat lifter cam...remove the lifter and inspect the bottom surface,,,,it is most likely tore up...if it is...time for new cam and lifters...if the bottom is still ok, the internal valve has collapsed ...replace the lifter if the cam lobe looks ok...

toolboxchev · 01-01-2019, 11:11 PM

If you adjust all the noise out and it returns in a short period (2 to 4 weeks) I would suspect the same.

Fuel mileage will absolutely go less that 6 mpg also. Even with these things I would still have movement on all the rockers when running. Certain valves on this engine were sunk over 3/16ths of an inch when the heads were pulled. Its hard to diagnose with even a compression test, use your best measurements and trust your gut.

It may be something else collapsing like a pushrod.

Myoldtruck · 01-02-2019, 08:35 AM

Aflter you made the adjustments to that one, could you see any movement of it while the engine was running. Only other way to confirm I would confirm the lobe is ok is to set up a magnetic dial indicator above that rocker and spin the motor by hand to measure the lobe somewhat.

Im about to run marvel oil in with my regular oil to help with lifters on the 71 gmc i just bought. before i make any adjustments. Hoping this will wake up any stuck lifters first.

toolboxchev · 01-02-2019, 09:05 AM

I would try this before Marvel Mystery Oil, Lord only knows whats in that stuff today as the EPA can regulate them and force them to change compounds in it.

Its been going on for years.

https://www.amsoil.com/shop/by-produ...code=FLSHCN-EA

01-01-2019, 09:02 PM	#1
Arl37 Registered User Join Date: Jul 2011 Location: Valley Center, Ca Posts: 277	Hydraulic lifter Collapse? I went to adjust the valve lash on my SBC 350 today. One of the rockers required much more tightening to eliminate the clicking than the others. In other words, the amount of exposed thread above the adjusting nut was much greater than on the other rocker studs. I wonder what could have caused this. I would appreciate you thoughts on this.

01-01-2019, 09:04 PM	#2
davischevy Senior Member Join Date: Sep 2008 Location: Harrison, Arkansas Posts: 9,786	Re: Hydraulic lifter Collapse? There is a good chance the stud has pulled out of the head. __________________ other Larry Build thread, Arkansas K10 https://67-72chevytrucks.com/vboard/...=755797&page=5 The ability to speak several languages is an asset, but the ability to keep your mouth shut in any language is priceless.

01-01-2019, 09:31 PM	#3
Arl37 Registered User Join Date: Jul 2011 Location: Valley Center, Ca Posts: 277	Re: Hydraulic lifter Collapse? Thanks for your comment, However, heads are Edelbrock E Street and i don't think the rocker studs screw directly into the heads. There is a plate for each cylinder on the head with a rocker stud on each side of the plate.. There is a bolt on each side of the plate that secures the plate to the head. I will check this tomorrow. Something's not right

01-01-2019, 09:49 PM	#4
Mike C Registered User Join Date: Dec 1999 Location: Austin, TX, USA Posts: 7,709	Re: Hydraulic lifter Collapse? The plates should be push rod guide plates that are required with aluminum heads, so you are correct that it would not pull out. Flat tappet cam? I'd be worried you wiped a lobe. __________________ 44 Willys MB 52 M38A1 64 Corvette Coupe 68 Camaro 'vert LT1 & TH700 69 Z/28 355 12.6's @110 69 Chevy Short Step 4 1/2"/7" drop 72 Jimmy 4WD 4spd 4" & 35's 02 GMC 2500HD 4x4 Duramax

01-01-2019, 10:33 PM	#5
AussieinNC Moderator Join Date: Jun 2017 Location: Cherryville, NC Posts: 2,155	Re: Hydraulic lifter Collapse? The lifter has most likely either collapsed or has junk in its sealing valve...or, the lobe has died and lost its lift ramp.... Either way, flat lifter cam or roller lifter cam, its to to pull the manifold and distributor...and remove the offending lifter... Roller cam...if the roller on the bottom of the lifter is intact, the internals of the lifter is faulty and the lifter needs replaced. If the roller is locked up or missing...you will have to pull the cam and replace all lifters and the cam. Flat lifter cam...remove the lifter and inspect the bottom surface,,,,it is most likely tore up...if it is...time for new cam and lifters...if the bottom is still ok, the internal valve has collapsed ...replace the lifter if the cam lobe looks ok... __________________ Family and country before all others... 2006 Chevy Silverado (Daily Driver) 2012 Chevy Equinox

01-01-2019, 11:11 PM	#6
toolboxchev Registered User Join Date: Jul 2015 Location: 2nd left past the stump on a dirt road. Posts: 2,629	Re: Hydraulic lifter Collapse? If you adjust all the noise out and it returns in a short period (2 to 4 weeks) I would suspect the same. Fuel mileage will absolutely go less that 6 mpg also. Even with these things I would still have movement on all the rockers when running. Certain valves on this engine were sunk over 3/16ths of an inch when the heads were pulled. Its hard to diagnose with even a compression test, use your best measurements and trust your gut. It may be something else collapsing like a pushrod.

01-02-2019, 08:35 AM	#7
Myoldtruck Registered User Join Date: Sep 2015 Location: Mohnton pa. Posts: 208	Re: Hydraulic lifter Collapse? Aflter you made the adjustments to that one, could you see any movement of it while the engine was running. Only other way to confirm I would confirm the lobe is ok is to set up a magnetic dial indicator above that rocker and spin the motor by hand to measure the lobe somewhat. Im about to run marvel oil in with my regular oil to help with lifters on the 71 gmc i just bought. before i make any adjustments. Hoping this will wake up any stuck lifters first.

01-02-2019, 09:05 AM	#8
toolboxchev Registered User Join Date: Jul 2015 Location: 2nd left past the stump on a dirt road. Posts: 2,629	Re: Hydraulic lifter Collapse? I would try this before Marvel Mystery Oil, Lord only knows whats in that stuff today as the EPA can regulate them and force them to change compounds in it. Its been going on for years. https://www.amsoil.com/shop/by-produ...code=FLSHCN-EA



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