29 replies to this topic

[Lima31]

Hi all


Just chasing some comments on how to deal with a ticking noise that appeared today. The engine has had a new cam (Crow 5761), anti pump lifters, new pushrods ... has run really well. The service notes indicated weaker than recommended valve springs for the camshaft but did not advise replacing at this point.

Today after warming the car up for 3 minutes, then driving for another couple of minutes, it took about 15 seconds for a ticking sound to appear. I turned around and took it easy getting home but the noise is still there. It felt like it was running on 7 cylinders and backfiring.

Still had 30-40psi + oil pressure, has std oil pump

I pulled the left bank rocker cover, and noticed one of the rockers over #2 cylinder appears loose on the pushrod. Surely this is the problem? This pushrod sits lowest compared to the other cylinders ...

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Am I right in thinking this a dead lifter, which means pulling the intake manifold off? The car has only done 200 easy km since the install, not including the cam run-in.

I take it that driving this car will only risk killing the (original) block, and I don't have the full tools (or expertise) to pull the manifold off and change the lifters, so is a mobile mechanic the way to go?

[rodomo]

Pull the pushrod out. It might be bent?

[LXCHEV]

If the rocker nut / posi-lock is still tight and hasn't come loose, then it kinda points to a suss lifter / bent pushrod / or wiped cam lobe ?

[makka]

If you can pull the rocker covers off, you can pull the manifold off!

thats what I would be doing, inspecting the lifter, pushrod(roll it across something dead flat) and the cam lobe on the dud cylinder

[Lima31]

Thanks for the responses - the rocker nut was on tight.

I pulled the pushrod out, it's clean and straight.

[Lima31]

You dont have a 9/16" spanner and 1/64th of a brain??

Mani off lifter out new lifter in is incredibly easy mate.

Cheers.

I have 1/65th, so will continue with stupid questions lol

Do all the lifters have to be replaced despite the recent use?

The hydraulic clutch cylinder interferes with right side rocker cover, and I don't have a torque wrench, so I'm hesistant to pull those items apart without the tools ...

[S pack]

You dont have a 9/16" spanner and 1/64th of a brain??

Mani off lifter out new lifter in is incredibly easy mate.

Cheers.

I have 1/65th, so will continue with stupid questions lol

Do all the lifters have to be replaced despite the recent use?

The hydraulic clutch cylinder interferes with right side rocker cover, and I don't have a torque wrench, so I'm hesistant to pull those items apart without the tools ...

No, they've had very little use so you should be able to just replace the faulty one. Unless of course you don't trust the other lifters to be OK for many miles to come.
Probably just a failure of the internal parts of the lifter but if the bottom of the lifter and cam lobe are badly worn you might want to check all the lifters and lobes.

[76lxhatch]

Looking at how low that pushrod is (its not even in the rocker seat) and given that the pushrod is still straight my first suspect would be a wiped cam lobe rather than just a faulty lifter... no way to be sure until you inspect it of course but if that's the case then the cam run-in wasn't right and all of it needs replacing (and the oil system flushed)

[Lima31]

It turns out the lifter was indeed crushed. The top 'ring' of the pushrod contact plate broke away from the base, which is jammed down into the bottom of the lifter.

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[76lxhatch]

Interesting, never seen one die quite like that before. At least it wasn't the cam though!

[Lima31]

Interesting, never seen one die quite like that before. At least it wasn't the cam though!

So true!! The other lucky thing was that the circlip held the ring in place, so we didn't have loose metal debris flying around ... will flush the oil through and change the filter anyway

[enderwigginau]

Check your rockers are moving properly. Possibly a tight rocker may have jammed the pushrod down while the cam was coming up.........

[warrenm]

Also check that you have clearance between the valve spring retainers & the top of the valve guide. Also check the pushrod, it may not be quite straight now.

[Lima31]

Thanks for the comments, I've replaced all the lifters, checked through as suggested and reassembled it all last night ... waiting for the silicon to cure, will then add coolant and then fire it up ...

[S pack]

Sweet just gotta wait for the manual to come in then, cheers guys

Now you don't have to wait.

Extract from Holden improved performance L6 & V8 engine service manual.
(Blue engines but Black engines are the same specs)
Coat threads of cylinder head bolts with GMH sealing compound Part No. 3835214
Tighten cylinder head bolts in two stages to 54 - 68 Nm and 91 - 102Nm in the sequence shown in Fig 3-38

[S pack]

Oops, just realised you need inlet manifold torque specs not cylinder head.
Will post them up tonight.

Cheers
Dave.