Ticking noise caused by worn valve tips?.

[turquise1]

Injectors were what I thought was the problem first when I used a stethoscope to pinpoint the problem. I replaced / cleaned out all of them and did not make any difference.

A mechanic friend told me it was a rod knock but I eliminated that by disconnecting ignition coils one by one which did not get rid of the ticking either.

I also checked the frequency of the ticking (5 times a sec, which is 300 per minute that is half of the idle at 600 rpm engine so it is not the crankshaft and almost definitely the camshaft)..

Cheers,

Ozzie

[80stech]

The hammered valve ends are a result of the tick not the cause.

[Purplefade]

Is the ticking on both sides or just one, you mentioned thick dirt like particles in the head, is it possible your oil lines are restricting flow and starving the valve train of oil? Excess heat in the valve train and lack of oil may cause the rounded edges too, would be like two smooth files working against each other of valve, rocker and lifter were “dry”?


Sent from my iPhone using Xoutpost.com

[turquise1]

Originally Posted by 80stech

The hammered valve ends are a result of the tick not the cause.

What would you mean by that? Some sort of blockage pressuring oil more towards some lifters and less towards others?

The ticking seems to come from bank 2. There is also spark plug oil fouling on cyl 6 which is the same side although I am not sure if related. I thought of blocked oil ports like the ones in the image perhaps. I am thinking of applying pressurized air to ports to see if any more dirt comes out..

Thanks,

Ozzie

[tartilla]

There is no doubt that these heads are very complex.

It really makes me appreciate the simplicity of the LS pushrod design. Though, they're getting pretty complex now too. Direct injection, cylinder deactivation, cam phasing etc.

With a hydraulic lifter, it's odd that the valve step would get hammered like that. Could the lifter have collapsed, and the lash created be the issue?

Spare heads for parts are relatively cheap, it's the effort getting them on and off. Not to mention guide work on 32 guides....and then valve work.

[ahlem]

Did you inspect the lifter bores for scars?
I found that some of the lifters and the bores on various M54 engines I looked at had some serious grooves. I replaced 6 lifters on mine. Granted this is 6 cylinder vs 8 so yours may be different. If your lifters leak down too quickly, they could be causing the clearance issue.

[turquise1]

Originally Posted by ahlem

Did you inspect the lifter bores for scars?
I found that some of the lifters and the bores on various M54 engines I looked at had some serious grooves. I replaced 6 lifters on mine. Granted this is 6 cylinder vs 8 so yours may be different. If your lifters leak down too quickly, they could be causing the clearance issue.

I have looked at the bores but did not see much damage. Some of them are slightly worn causing some lifters to very minimally move side to side but not sure that would cause the issue. I also did not see any collapsed lifters. They all came out stiff, full of oil. I disassembled a couple of them and once the oil inside them is drained, they become compressible once again. I have purchased a couple of new ones to compare their movement though.

I am replacing the valve stem seals right now. I did not see any broken springs or any other problems in there yet to cause a lifter tick. I was told there would be blockages around oil passages inside the head so I am planning on putting air pressure inside wherever I see a passage to hopefully open it up although in any oil blockage problem, at least one lifter would not get enough oil and it would come out collapsed, wouldn't it?

Thanks for all the opinions once again..

Ozzie

[turquise1]

Originally Posted by ahlem

Did you inspect the lifter bores for scars?
I found that some of the lifters and the bores on various M54 engines I looked at had some serious grooves. I replaced 6 lifters on mine. Granted this is 6 cylinder vs 8 so yours may be different. If your lifters leak down too quickly, they could be causing the clearance issue.

So, after replacing the valve stem seals (most of them badly worn out) and not seeing any damage on the springs to cause ticking, I decided to look at the cams one more time. They are definitely worn out a bit and there is some scoring on journals as well. My car is at 200k+ miles so I guess it's normal. Now, of course the question is, would that cause the ticking?


Please take a look at the photos and let me know what you think..


Thanks,


Ozzie

[Purplefade]

Ozzie,
I do see some run pattern on those cams but I wouldn’t guess that (unfortunately) is the source of your ticking. I guess it is possible that if a cam lobe was worn down so significantly that it took pressure completely off the rocker in some point of its rotation that it would be possible, but I don’t see that kind of wear there.

I think back to 79 when chevy put bad cams in the 79 camero 350s. I, unfortunately, bought one and just outside the warranty I had a significant loss of power and when we pulled it apart to diagnose we found lobe one nearly completely rounded off, nearly no lift on those valves and it didn’t tick. I realize different time, different engine, but you yourself said you used a feeler gauge (or other measuring device) on the rockers and didn’t notice any significant gapping...

I really doubt that’s the smoking gun ☹️. Though restricted oil lines may be contributing to the wear, I would definitely make sure those are cleaned out.

You may have said this, but does turning it over by hand generate any tick, or is it only at idle and above? I’m wondering if you don’t have a worn spring retainer that may be moving around on the spring / in the spring cap as that lobe rolls over it. Inspect your spring keepers, keeper seats and spring caps maybe, just to be safe.


Sent from my iPhone using Xoutpost.com

[andrewwynn]

Frequency of tick? How many ticks per revolution, figure out if it's just one cylinder or half a cylinder.