Strange Engine noise

[sapote]

No, when checking the valve lash, I spent a couple of minutes checking each rocker, mainly by feel and under different light angles, you can slide the rockers to the side and can inspect them. only the exhaust side needed a bit thicker shims (0.02mm). I tried as much as I could to stay mid point of the spec, or toward the tighter side of it.

Yes, I like the tighter side and so my suggestion for the clearance is 7Eleven -- 0.007 intake and 0.011 exhaust.

[x Spades x]

Yes, I like the tighter side and so my suggestion for the clearance is 7Eleven -- 0.007 intake and 0.011 exhaust.

Ok so I have the valve cover open.

I used the screwdriver technique and tracked the noise down to cyl 6. I open it up and started check all of the clearances. They all seem to be about .25mm but some can possibly fit .30mm. I have Achrick 288/280 which says .25mm.

so the question is:

1) Is that lipped cam lob concerning, as in is the cam ruined? When lash is measured, it's on the back side of the lobe. So I can measure .25, but the lobe is still "short".

2) Do I adj all lashes to .30mm?

[x Spades x]

Also, I can't inspection the rocker, as it's the farthest back. The clearance is .30mm. Engine is SLIGHTLY warm.

[Anri]

is that lipped cam lob concerning, as in is the cam ruined?

You can kiss the cam and the rockers arm/s

Pull the spring/clip and gently move the rocker arms and enjoy the flatness.

Regards,
Anri

[sapote]

" I can measure .25, but the lobe is still "short"."
what do you mean lobe is still short?

Again, IN should be 0.007" (0.18mm) and EX should be 0.011" (0.28mm)
You said 0.25 and 0.3mm but the ex and in valves have different clearance.

[sapote]

If you pull/slide the rocker off the valve end, becareful not to loose the small shim under the rocker.
I don't see anything obvious wrong with #6 cam lobes.

[Anri]

I don't see anything obvious wrong with #6 cam lobes.

Zoom the 2nd picture and you will see it.

Regards
Anri

[x Spades x]

" I can measure .25, but the lobe is still "short"."
what do you mean lobe is still short?

Again, IN should be 0.007" (0.18mm) and EX should be 0.011" (0.28mm)
You said 0.25 and 0.3mm but the ex and in valves have different clearance.

I have 288/280... both intake and exhaust should be .25mm lash.

I mean since the lobe seems to be worn down a little (hence the lip), it's slightly shorter than the other lobes when depressed the rocker arm. So wondering if I can put a bigger shim on that's tighter than the .025mm, to compensate?

[x Spades x]

You can kiss the cam and the rockers arm/s

Pull the spring/clip and gently move the rocker arms and enjoy the flatness.

Regards,
Anri

It's the back rocker. You can't push it totally off the spring to feel it.

[Anri]

It's the back rocker. You can't push it totally off the spring to feel it.

All you need to move the rocker just little bit and you will see it.
The lobe before is also on the way to get ruined....that one you
can move and drop down so you can visual see it.


Don't start and contaminate your engine with metal particles.


Regards,
Anri

[x Spades x]

All you need to move the rocker just little bit and you will see it.
The lobe before is also on the way to get ruined....that one you
can move and drop down so you can visual see it.


Don't start and contaminate your engine with metal particles.


Regards,
Anri

it's to tight to actually see the flatness.

Also, these cams have a out 100k miles on them, so they won't look super clean... but what causes this? What causes flatness in the rocker? I'm assu.i g we are saying the rocker gets flat and damages the cam? If so, what causes the rocker to fail?

[sapote]

Zoom the 2nd picture and you will see it.

Regards
Anri

Now I can see the ridges near the edges of the EX lobe. The lobe has worn down too much.
You have professional sharp eyes.

OP, with this much worn and clearance, why the measured gap is only 0.3mm? I would say more than 0.6mm now.

[x Spades x]

Now I can see the ridges near the edges of the EX lobe. The lobe has worn down too much.
You have professional sharp eyes.

OP, with this much worn and clearance, why the measured gap is only 0.3mm? I would say more than 0.6mm now.

I just put the largest shim in the wiseco box (2.6mm) and the clearance is still too much.

[sapote]

I have 288/280... both intake and exhaust should be .25mm lash.

I mean since the lobe seems to be worn down a little (hence the lip), it's slightly shorter than the other lobes when depressed the rocker arm. So wondering if I can put a bigger shim on that's tighter than the .025mm, to compensate?

No compensation with thicker shim will work.
The harden layer on lobe and rocker are gone. Need replaced.

[Anri]

it's to tight to actually see the flatness.

You can but seem like it's hard for you. Do you have small mirror ?

what causes the rocker to fail?

If understand how it works its easy.

I will respond tomorrow on that subject.

Regards,
Anri