Use the stick to check closely sound from under the rocker covers. I once had one of the spacers in the rocker cover gaskets fall off and get hidden in the top of the head. Of course, if the mechanic did a thorough job, this is extremely unlikely. But that little sucker just might be in there causing havoc.

 

A pix of a "missing wrench" that one member found after repairs by a shop resulted in "engine tick" .

 

You will be surprised

 

Hello Everyone -

I've haven't checked the site since my last post but now that I have, I need to say thanks for the suggestions on things to trouble shoot.

From the start I figured it was something creating a vibration against the firewall so I will double check all the plug connection to the coil. I will also take the belt off and have a listen as I hear it the most at idle.

The sound is really hard to hear from the engine compartment but very easy to hear on the drivers side interior. Once or twice I could hear it from the engine side of things but it was very quiet.

The mechanic that did the work took his time to do everything, put new wire covers on and not the cheap ones, upgraded some connections on the throttle body, cleaned everything he could in a parts cleaners, etc. He's been building engines for 30 years so I'm hoping he didn't leave something behind or not assemble something properly. The engines he works on are all high performance and diesel.

Once I do the suggested checks that you have all provided I will provide and update.

Thanks again everyone!

 

Pretty easy to figuree out.
Mechanic did not fully connect up the IAC distribution pipe which is rattling.

pipe is behind the engine like a large wishbone.

 

Like 34 and 35 in attached?

 

I know where the idle air control motor is, on top of the engine, it is all connected properly at that point but I am not aware of any pipe for it. Does it sit high behind the motor or down lower and where / what does it connect to?

The only pipe running behind the engine, up high, is the one for the secondary air which connects into the SAI control valves and back to the pump but this pipe is secured to the bracket. Is there some sort of pipe which sits below this one that could be in contact with the firewall?

 

With the vehicle running / at idle, the Idle Control Motor was disconnected from the power supply and the knocking sound was still present.

The vehicle is idling properly.

 

So, IAC pipe is lashed down - that's good.
OK so put your hand on the engine when you hear the knocking sound.
Maybe on the oil filler tube.
Can you then feel the knock?
That would mean main or rod bearings.


Engine mounts are fine?
Transmission mounts fine?

If you go into reverse when you hear it knocking and put the brake on and take it to say 1,000 RPMs knock gone?

Or do the same in Drive?

This would indicate mounts.
the engine will tilt if the mounts are bad under load and it will
hit the metal chassis or frame eventually.

Or

Exhaust pipe hitting the frame anywhere?
Check the bend in the back. It gets near the frame.

I had to buy steel cable and tie to my exhaust pipe and to a street lamp light post and yank my exhaust.

As the previous owner was rear-ended and that bent the exhaust pipe causing it to hit the frame.

 

Jfall,

Thanks for all the suggestions.

The sound changes pulse while in park idling. I think there is something that is touching the firewall which makes it easy to hear inside but it can't be heard around the engine due to all the other noise.

Unless there is something that could cause this issue behind the dash and it conveniently started that same time after the head gasket was done.

I need to figure out what would cause the pulsing / rapid knocking sound, what pice of equiptment behaves like that? It seems like the knocking is the fastest when coming to a stop after driving between lights.