Thom

This problem is driving me nuts.

Step 1 :
Refreshed head (new guides, new seats, surfaced), new lifters, new oil check valve, new valve springs, new Ti valve retainers, used cambox, used camshaft, used valves.
Observation : lifter #4 noisy at idle.

Step 2 :
Cambox taken off, lifter #4 shot, camlobe #4 shot.
Checking cambox, using another used camshaft with a new lifter #4.
Observation : lifter #4 noisy at idle

Step 3 :
Cambox taken off, almost all lifters shot. Camshaft shot as well.
Replaced with another cambox with slightly tighter bores, another used camshaft, with used original lifters known to be good.
Check valve noticed to be faulty. Taken apart and rebuilt with a softer spring.
Observation : all lifters more or less noisy at idle, lifter #4 still slightly noisier than others.

Engine fully warmed-up, oil pressure at idle is 4 bar.

What to do now?

Dump the oil check valve?

Why is lifter #4 consistently noisier than others? Would something wrong with the height of valve #4 cause lifter #4 to be consistently noisy?

reno808

oh dam thats sucks. i would have done the same.. i am stumped. how is the oil pressure?

Thom

Yes sorry I forgot to mention this obviously necessary detail - oil pressure at idle is 4.

reno808

Mine is at 5 at startup worse case 4.5 I post recent videos at idle and shows this as well. might be a lead

Tedro951

So you're saying you've wiped out 2 camshafts since the refresh. Sounds like you may have one of the bad cam housing gaskets that were marked "top" incorrectly.

Thom

I have seen the threads on cam housing gaskets with the wrong marking, but I can't figure out how people can install them upside down since it's physically impossible.

Paulyy

Some people are physically stupid...


I doubt it could be the gasket, any normal person would line up the gasket with the holes on the install.

no clogs in the passages? is the oil clean?

Richgreenster

What oil are you running?

Thom

Fresh Castrol Edge 10W60, BMW M spec.
Oil passages were carefully cleaned before assembling the cambox.
I took off the plugs on the cambox and saw that oil was flowing plentiful, so I suppose the oil check valve opens as it should.

reno808

take pictures. might be better to diagnose

tyro

Did the problem begin with the refreshed head, or was it rebuilt due to noise?

Tedro951

Since you have swapped cam/box/lifters, the valve height would certainly be something I'd be curious about, especially since you've witnessed oil flow in the box.

Richgreenster

+1

Thom

I will shoot a video over the weekend.

I got the head separately and used it for a new engine build. I ignore how it performed on the engine it came from.
I had the machine shop replace valve guides, valve seats and resurface it.
I used this machine shop several times for other 951 heads before and they always did a good job.
The head was carefully cleaned before being assembled.

Considering the cam housing gasket, does anyone know why it comes with a hole for the oil check valve smaller than the bore in the head where said oil check valve sits?
Maybe this is how they already originally came on new engines from the factory, but I don't understand why the hole is smaller. I'm not sure I ever saw an old, original cam housing gasket as fitted from the factory.

Chris White

Its not impossible – you are thinking about turning it around so that the intake side is on the exhaust side – that is impossible. But it you flip it over so that the side that should be against the head is against the cam box you will block off the oil port….and it will fit just fine! The only thing that is not symmetrical is the hole for the cam box oil port – block that off and you are going to have a problem just like the one you are having!!