326 Startup.... Bad Knock...

[Dark_horse]

Ok so here is a video... primed the motor with the spark plugs pulled... lots of oil pressure... didn't hear any knocking noises...

Couldn't get litos tune to start it up ( cant get the damn data log to register any data either)... I pulled the MAF and it fired right up, heard the knock and gave it a minute to see if it went away...

The motor was starting to lean out so I just turned it off...

Even though the Motor was running pretty smooth there is definitely something wrong...

My heart sank!!

I used an all new timing set with cams installed heads up one the timing marks. Cams are stock regrinds

The heads were used... I took them to a shop that replaced the bent valves and said the rest were good and all the combustion chambers vacuum tested good... Starting to doubt the shops work...

Short block was assembled by a reputable machine shop and im not worried there...


What to do now?... I will pull the valve covers off tomorrow and look for any obvious issues...

What should be my process of elimination be after I pull the covers?

Any help or suggestions are much appreciated as always...

 

[stang389]

do you have a windage tray in the oil pan? i have seen in other motors where this isn't installed with the correct gap where it can make the knocking noise

 

[downtime!]

Hard to tell from a video, but that noise does not sound low in the engine to me. Sounds up high, like in the valve train.

 

[GT E UPP]

Hard to tell from a video, but that noise does not sound low in the engine to me. Sounds up high, like in the valve train.

Agree with Downtime here...!!

 

[fordracer666]

Def sounds like a upper end noise .

 

[LAStang1234]

Loose follower?

 

[Dark_horse]

do you have a windage tray in the oil pan? i have seen in other motors where this isn't installed with the correct gap where it can make the knocking noise

It does have a windage tray. ... not sure how that could be installed wrong??

 

[Sinner]

I've had a fox that had the oil pick up tube hitting the crank before. Tolerances are tight in the oil pan and easy for something to be misaligned.

How ever I really can't say for sure what that sound was from in the video.

 

[mikeyfitz]

Sounds like the followers.

 

[LAllison20]

Stock Regrinds? Does that require a shim under the lash adjuster like the BBR Stage 1 regrinds?

 

[UltraKla$$ic]

Does sound like top end. Maybe followers contacting valve cover(s)? Did you use high lift springs? Or one heck of an exhaust leak?

 

[saleen07gt]

I would pull the valve covers and have a look see.

 

[nathanielwilliam]

Take a piece of hose or stethoscope and pinpoint the sound. That will narrow down your search quite a bit.

 

[lethe]

I had a loud ticking similar to that when i swapped my new motor in. When i pulled the valve cover off one of the followers wasn't sitting on the valve stem. It was sitting on top of the spring retainer right new to the valve stem. Does it sound like the noise is only on one side?

 

[hamish]

It does have a windage tray. ... not sure how that could be installed wrong??

On a 3.8" stroke crank, it may be necessary to modify the windage tray.
I know mine needed it.
Stock windage tray that is.

 

[Dark_horse]

Ok I am 99% sure I have figured out...I had a couple buddies over tonight who all turn their own wrenches...I figured a few more ideas and minds wouldn't hurt.... I unhooked all the injectors, cops and took the spark plugs out....we primed the motor until it was reading 60lbs on the gauge... gauge was hooked up to the oil feed line for the turbo... Fired it up and the all chain slap that we heard before went away after 20 seconds... The noise in the video was still prevalent however... The motor was running soo smooth on Litos tune I just let it warm up... (pretty rich on idol but I figured that was just the starting point)... I let it cool down and then started it again... absolutely no valve train noise what so ever but still knocking... then the one guy who doesn't know shit about cars pipes up and says " hey I don't think it was making that particular noise when you were priming the motor"... so then we got to thinking that starter was hanging a little bit and making the knock noise... crawled under the car and sure enough the sound is coming from that area. I guess its possible the starter could have rusted a little bit since its been out of car for 6 months. Decided to give it a little gas while the car was idling and the knock goes away... Going to pull the starter tomorrow morning and bench test it... probably just go ahead and get a new one... We are all 99% sure that is the issue... motor was just purring like a kitten...


Anybody have any other ideas that we havn't thought of? Ideas of why the noise would go away when you rev it a tad?

 

[muztangman93]

I dont think its the starter. I would pull the valve covers and see whats going on under there. Im not the best mechanic in the world by any means but that definetely does not sound like a starter. Definetely sounds like its top end due to the loudness of the noise being picked up in the camera. If its bottom end and its that loud your likely going to be spending a bunch of money to figure out the issue and fix it, But I hope that is not the case and I hope Im wrong and it is the starter that would be wonderful.

 

[Dark_horse]

pulled the vc and nothing looked out of the ordinary.... I think in the video posted above there is a lot of extra noise that is coming from the top end... once primed all that went away...listened through a screw driver and the top end is running smooth as butter... there is however still a knocking noise coming from somewhere in the bottom end... you cant hear it when the starter is engaged but you can when its running... which leads me to believe the starter is dragging... also when you speed up the rpms the knock disappears... I put my hand on the oil pan and you can feel a slight knock... put your hand on the tranny by the starter and it is amplified by 10x...We shall see in the morning I guess....

Another thing the knocking noise did get faster with rpms added but not consistently... by 2500 rpms the knock disapears

For those wondering about windage tray and oil pick up tube I have ruled those out...

 

[05stroker]

Is it an auto car? If so check your torque converter bolts.

 

[86GT351]

Ok I am 99% sure I have figured out...I had a couple buddies over tonight who all turn their own wrenches...I figured a few more ideas and minds wouldn't hurt.... I unhooked all the injectors, cops and took the spark plugs out....we primed the motor until it was reading 60lbs on the gauge... gauge was hooked up to the oil feed line for the turbo... Fired it up and the all chain slap that we heard before went away after 20 seconds... The noise in the video was still prevalent however... The motor was running soo smooth on Litos tune I just let it warm up... (pretty rich on idol but I figured that was just the starting point)... I let it cool down and then started it again... absolutely no valve train noise what so ever but still knocking... then the one guy who doesn't know shit about cars pipes up and says " hey I don't think it was making that particular noise when you were priming the motor"... so then we got to thinking that starter was hanging a little bit and making the knock noise... crawled under the car and sure enough the sound is coming from that area. I guess its possible the starter could have rusted a little bit since its been out of car for 6 months. Decided to give it a little gas while the car was idling and the knock goes away... Going to pull the starter tomorrow morning and bench test it... probably just go ahead and get a new one... We are all 99% sure that is the issue... motor was just purring like a kitten...


Anybody have any other ideas that we havn't thought of? Ideas of why the noise would go away when you rev it a tad?

So you are hearing the noise in the Starter area the loudest. Is the car a stick or Automatic? When the motor was put back in if it is an Automatic are you sure all the Flex Plat Bolts are properly secured?