Camshaft Bearing Question

[6meter]

Re: Camshaft Bearing Question

I'll second the shutters. I doubt its a cam bearimg. I think you found some mechanics that know what the problem is and will go along with your diagnosis for the $$$$.

 

[Kmort]

Re: Camshaft Bearing Question

I siphoned about 10 oz of oil from the dipstick and ran it through a coffee filter and got nothing. I used the scope over where the flappers are and got nothing.

 

[TiredoleBoy]

Re: Camshaft Bearing Question

I have rebuilt a few engines in my time. But one thing i have found is this. If the cam bearings are shot, you can be assured the crank bearings are close behind failing. I would pull this ( providing the bearings are really bad) and do a complete overhaul. While at it replace the oil pump.
Typically a noise like this would be more a gear or chain slap if it is isolated at the cover. A cam bearing would be something you would know very quickly.
I would have to say check the timing chain first. Move the distributor and see what changes occur. If the chain is bad you could move it to where ever before it causes a misfire.

 

[TiredoleBoy]

Re: Camshaft Bearing Question

This is interesting!!!

Since my last post I've had 2 more mechanics take a look and listen, and again STUMPED and countering everyone else's theory.

The one guy said since it still runs and performs good... "Don't fix it until it's broke", which at this point I tend to agree (or perhaps just want to). He said it's a lot easier for a mechanic to find something broken.

Since I'm not able to tear down an engine and put it backk together, I guess I'm just pretty well screwed since it would cost a small fortune to pay a mechanic to do so.

Depends where you are at. I have everything from my last career. Engine hoist, lifts etc.......

 

[Kmort]

Re: Camshaft Bearing Question

I have rebuilt a few engines in my time. But one thing i have found is this. If the cam bearings are shot, you can be assured the crank bearings are close behind failing. I would pull this ( providing the bearings are really bad) and do a complete overhaul. While at it replace the oil pump.
Typically a noise like this would be more a gear or chain slap if it is isolated at the cover. A cam bearing would be something you would know very quickly.
I would have to say check the timing chain first. Move the distributor and see what changes occur. If the chain is bad you could move it to where ever before it causes a misfire.

Did I not mention... I'm NOT mechanically inclined?

I have someone coming tomorrow who is mechanically inclined and interested in buying the boat. Hopefully he does and I will just cut my losses and move on. If not, I might see what it would cost to have my nephew drop in another engine.

 

[a70eliminator]

Re: Camshaft Bearing Question

Probably something reletively simple, when an engine waterpump bearing goes bad the impeller will make all sorts of clattering sounds, thats why I said to run engine with belt off just to rule out the pulley driven stuff.

 

[Kmort]

Re: Camshaft Bearing Question

Well the guy and really like the boat and was what he was looking for and everything. However, just like the rest of the mechanics he was totally baffled by the rattle. He has rebuilt many of these engines and can't figure it out, so he decided to pass.

I called the guy who was the only one that said he knew what it was. A loose balance shaft and I called him tonight. He told me it is unusal and that he has only had 3 of them of hundreds he has worked on. He said he could fix it but advise me that if I was going to keep the boat I'd be better off droping in another engine.

 

[Kmort]

Re: Camshaft Bearing Question

FYI... It was the needle bearing to the balance shaft. Now does anyone know what or how such a thing happened?