Bad tapping noise, could this be a fuel injector?

[Daz666]

Having got my M20 started after 10 years standing its got a very bad knocking noise that seems to be resonating from the inlet manifold.

It sounds exactly like this https://youtu.be/v22rUzIR7sg This is not mine but it sounds exactly the same.

It turns over on the starter fine with no noise but clatters like mad once started.

Could this be the fuel injectors?

Has anyone heard this before and found the cause?

Thanks

[aimlessrock]

after 10 years standing i assumed you had the cambelt changed ?.

The noise could be from the injectors, but in truth after 10 years standing you would be wise to remove and have them professionally overhauled in any event.

[fixedwheelnut]

Having got my M20 started after 10 years standing its got a very bad knocking noise that seems to be resonating from the inlet manifold.

It sounds exactly like this https://youtu.be/v22rUzIR7sg This is not mine but it sounds exactly the same.

It turns over on the starter fine with no noise but clatters like mad once started.

Could this be the fuel injectors?

Has anyone heard this before and found the cause?

Thanks

If it is that loud it sounds more mechanical either big end or camshaft, possibly a broken rocker or sticking valve, use a long screwdriver like a stethoscope along the top of the rocker cover and see if you can position which cylinder is loudest, easy to remove the rocker cover and check camshaft and rockers.

As @Daz66 mentioned should have a new cambelt on it as they are 60,000 miles or four years which ever is soonest so ten years is 2.5 times overdue

[Daz666]

Thanks for the comments.

I've used a screwdriver to my ear along the rocker cover and is seems pretty consistent all the way along. However putting the screwdriver on the inlet manifold and its much louder. Also your can feel the knock more with a hand on the inlet manifold which is where I was going with the injectors.

I'd changed the cam belt before attempting a start; it turns over freely by hand also on the starter. I've check the valve clearances and everything seems OK under the rocker.

As you can imaging the 10 years have not been kind. It was needing some body work when I parked it and much more is needed now. I was wanted to check that the engine was sound, before committing to the project.

Thanks

[wilma84]

VERY late response but did you ever find a solution to this? I had exactly the same noise coming from my engine after I took the injectors out to refurb them... I'm pretty sure it was due to a small amount of debris being stuck in the injector port. Anyway, if you haven't fixed it already, I'd start by refurbing the injectors and making the sure the ports are clean

[Daz666]

Yes, embarrassingly the timing belt had ended up 1 tooth out

Readjusted and all was quiet again. The heads coming off, so I'll have to wait to see if I've damaged anything. I'll be refurbishing various parts at this point. Thanks