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Tips
Tips

Engine clacking at 4k rpm.

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It's hard for me to tell on the video. Can you isolate it using the broom handle/screw driver in the ear test?
 
Trevor Jessie said:
Can you isolate it using the broom handle/screw driver in the ear test?
Click to expand...
Forgive me, I don't know what this is. Please elaborate so I can explain to my neighbours that I'm perfectly fine.
Tnx.
 
Why heck, think I would check the rocker arm adjustment first. What you guys think?
 
He's not got valve-train noise until the thing is twisted to high RPM, so that's why I think there's some rocker/shaft prob with adequate oiling. I may be all wet here, but that's my take on this.

Baz: A screwdriver or broom handle placed at various points around the engine while running (NOT near any of the spinny bits, PLEASE!!!) will amplify and isolate the loudest area... the likely source of the noises. Your ear to the 'other end' of course.
 
A wooden broomstick, my ear and various parts of the engine suggest that the valves on #4 are the culprit. They, it, them, I can't isolate intake or exhaust, but they are considerably louder than the rest of the cylinders and a little deeper.
I did splash a little oil in there while it was running, didn't help much if it did at all.
Neat tip BTW.
 
Finally, lol It does sond like something loose in the valve train. Let it cool down and take off that valve cover and check for any looseness. You might have an adjudting screw that has come loose or something. If you suspect no oil getting up there. Start with the valve cover off and confirm. Not for long though cause of the possible mess.
 
I had a top end oiling problem that sounded very much like your "Youtube."

I also had a 240z that had an idler pulley on the water pump belt with a bad bearing that would make all kinds of racket like that. Could you have a bad bearing in your alternator or water pump? I have also heard water pumps making a lot of racket like that when they start to fall apart.
 
Morris said:
I had a top end oiling problem that sounded very much like your "Youtube."

I also had a 240z that had an idler pulley on the water pump belt with a bad bearing that would make all kinds of racket like that. Could you have a bad bearing in your alternator or water pump? I have also heard water pumps making a lot of racket like that when they start to fall apart.
Click to expand...
He could slip the belt off and fire it up for a sec and see if the noise goes away, but not for long with no water flow.
 
Would be so easy to chech the valve train. Pull the cover with the engine at idle and use a feeler guage. Would take all of five min total.
 
I absoutely must agree with Jack. Pull that valve cover and check the valve lash. There is certainly a mechanical noise, possibly due to lack of adequate lubrication.

Also do as Kim said. Pull the belt off, pull the vc off and fire it up for no more than a minute, just like in the video. If the noise goes away, it is probably belt related (water pump, generator). If no oil is splashing, especially from the area of #4, there might be clogged oil galleys in the valve train.

That sure is one noisy engine.

I don't like to think of the alternatives, like the dreaded _.-' piston slap '-._ ... but it is a possibility.

Donn
 
I will pull the cover off this evening.

Please tell me about the anatomy of the oil galleys. The head was cleaned by the machine shop, and I cleaned the valve train, lubed it before it went back on.......
I'd like to know the path that oil should take, what I know is from oil pump up the aft end of the motor, then over the top correct?

Before I start pulling heads, I'll check the valves.

*DING*

I bet it was the cheap head gasket, didn't have a hole in the back end or something silly like that.
 
Won't be a LOT even if it's working correctly. But you should have some visible flow from around the rockers at the shaft. Some running down the pushrods, too.

Have you checked the clearances? It is awfully "rattly."

I couldn't really make out whether there was oil where it should be.
 
Are you using standard rockers? Not using 1.5 ratios or anything like that...those can make a noise when they hit the valve cover.
 
Durn it, check the valve clearances.

Then poor some oil, not a lot over the whole mess and start up at idle. No faster, oil will go everywhere if faster than idle. Make sure the lifters get some oil as well.

If adding the oil at the top did not solve it, shrug. If it quieted down you know what needs to be done.
 
Can't find me feelers. I'll buy new ones on my home from work....
Quick question then....
Will, if the valves clearances are out, they produce some of the same or similar symptoms as detonation? Such as hot cylinder head, power loss, noise at higher rpm?
 
Noise at all RPM but the higher the more noise.
 
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