Engine noise

[M3powerzz]

Thanks, here is a pic of the chain tensioner hole.

[sapote]

The threaded hole still has plenty good threads.
It's safer to chase the threads from inside to outside, but you also can do this from outside by using a guide -- something with the inner diameter same as the tap OD and place the guide flat against the hole lip -- this will huide the tap straight. The tap should turn free after a few turns. If not then stop and check, or run from inside.

[M3powerzz]

I tried to clean the threads today but the tap wasn't the correct size, I used a m22x1.5. it was too small.

I found this post, so I figure it's m26x1.5. it says it on post #8. It don't list s54 engine. But they got 2 sizes 22 and 26, I will try the 26

https://nam3forum.com/forums/forum/m...sioner-w-o-oil

[sapote]

My bad. Can you measure the tensioner diameter?

[M3powerzz]

It's ok, I will measure it.

[George Hill]

I may be late to this party but what all have you already replaced?

Did the valve cover break because the chain hit it (there will be witness marks in the shape of the chain)?
-If so did you do a leak down test to see if it had bent valves?

I had a similar failure with a customers car years ago, one of the tabs dropped onto the chain, then rode it up and got between it and the gear which lifted the chain blowing a hole in the valve cover like you have pictured. That car didn't bend any valves but it did tear up the sprockets AND the Timing Chain (amongst other parts as well).

Just throwing this out there to make sure you are fully repairing this failure... From your pics and short replies I think there is likely more damage in this engine and you are going to be chasing failure after failure if not done correctly.

[01SG]

I may be late to this party but what all have you already replaced?

Did the valve cover break because the chain hit it (there will be witness marks in the shape of the chain)?
-If so did you do a leak down test to see if it had bent valves?

I bought my car with a blown engine. This is exactly what happened. The chain blew a hole in the valve cover and a bunch of valves got bent. Failure looks exactly like OPs. I'm assuming it was a Vanos failure, but I never opened it up. Have had the thing sitting in my garage for the past decade waiting for a rebuild. Did get to fish the valve shims out from all over the place to use in my new engine though.

[M3powerzz]

The valve cover does break because of the chain, I didn't do a leak down test as yet.

[George Hill]

The valve cover does break because of the chain, I didn't do a leak down test as yet.

I would suspect the timing chain is damaged, I would VERY thoroughly inspect the inside and outside of the links... But if it was mine or my customers I would replace the chain and sprockets at minimum.