Knocking coming from top of the engine

LOUD tapping noise coming from valve train... ' Mustang Forums at ...

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Nov 16, 2010 - Last night on my way home from work something broke in my engine. I have a 98 GT. It sounds like it's coming from the top of the passenger ...

What the heck is this sound...?? Too loud for normal valve ...

? 0:11
https://www.youtube.com/watch?v=IMp1H8-0BSE
Aug 9, 2013 - Uploaded by team14robot
Freeing up a stuck valve without having to tear the engine down - Duration: 11:38. by dawino6260 47,255 ... 2005 scion tc enginetap/knock.

Could be a bad hydraulic lash adjuster. Use a mechanics stethoscope to find from which head it comes. Then you will have to remove the valve cover from that side (cold engine) and feel each adjuster if its spongy. They should all be hard. You will need to rotate the crankshaft with a socket on the balancer bolt to be sure that each valve is closed at a time.

This is hard to say with hearing the noise but try to pin point the noise , is it coming from the top or bottom of the motor , the knocking noise could be a bearing in the lower motor or may be something else making it sound like a bearing,

Hard to say over the internet but I will try to explain. If the noise is a distict KNOCK KNOCK and it sounds like it is coming from the bottom of the engine, then it most likely is a rod or main bearing. If it is a TAP TAP noise that sounds like it's coming from the top of the engine, then most likely a valve lifer is failing/failed.
the fact that it goes away when the car is warm, makes me lean towards a bad lifter. Normaly if a bearing is bad and knocking, the noise doesn't go away.

The KNOCK noise will be somewhat hollow sounding and the TAP TAP sound will be more solid. If the KNOCK KNOCK is solid, then a rod or main bearing has most likely failed to the point that a new/reman engine will be needed.

might be the valves have been damaged running without oil
- or the crankshaft / camshaft / main bearings
most probably you have to let the engine be rebuilt by a mechanic
(expect cost of more than US$ 2.000)
or get another (used) engine at a scrapyard

Could be a push rod, or other things like that. knock means something in your engine has come loose or is broken, the knocking you hear is that piece of metal banging around in your engine. the longer you let it knock or tap the more damage it does.

Sounds like you didn't put the pushrods back in the proper locations. There are two different lengths in this engine and you may have one backwards

Most likely cause is a hydralic tappet. Mits are well know for top end noise. Note we are talking about a tapping or clicking sound not a knock. You can try using an engine flush product if the noise is getting bad and then changing your oil. Generally if the oil is not changed regularily eventually the tapping noise gets happens.

Engine knock Huh? In order to qualify the term "Knock", Let me get you to perform some simple task/observation. Typically, if you hear a noise on top of your motor that can be described as a light knock, usually going tap, tap, tap, tapping along at double the tempo, of your motor spinning, Your oil pump may be having trouble getting oil to the top where the valve's and rocker arms are. If you hear a "Knock" by bending over or kneeling beside one of your "front wheel well's"and stick your head up to the well, providing a vantage point to "hear" whats going on at the lower part of the engine. A knock from here will/can indicate a potentially overheated, under lubricated, rod or crank bearing that could seize the motor. This (theretical) crank bearing would be sounding off at half the tempo of the rocker arms above., with a deep, dark klunk that would defintly present itself as the sort of noise that damages metal parts. Now, that being said.....common sense goes a long way, people....1.) Most people are aware of the maintenance that has been performed on a particular engine, the quality and quantity of that maint. and when the last time it was ran out of oil or water. For those who fall into the " lack of maintenence" catagory, you probably already know why your engine or driveline sound as it does. If you happen to take particulary good care of your car, there is a good chance that whatever noise or "happening" might be going on, it'll be much easier to remedy. There are always exceptions to every rule. Remember, its not what will happen, it's what can happen. Take care of your car, and it will take care of you. Theroad

If it is coming from the top of the motor, I would say it is a lifter tapping. If the sound is coming from the lower end of the motor I would say you have a rod knocking. If it is alifter you can replace just that lifter, if it is the rod I would consider a rebuild.