Loose Cam Follower, need help! Video included

K7Stang

New Member
Nov 21, 2018
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21
Ohio
What’s up guys, i’m new to this forum so forgive me, but i really need help. So, story of the car, its a 2000 V6 mustabg, that I swapped to a 97 4.6. I bought the motor, did an overhaul, all new bottom end bearings, bolts, oil pump, rings, etc etc. Originally, when i built the motor, i had NPI heads on it, stage 3 comp 270 cams, trickflow lash adjusters and that was about it. Well, I recently decided to do the PI head swap. So i picked up a set, had the machine work done on them, ported and polished them, then installed them. Well i got the car to run, and when it first fired up it sounded beautiful. Ran great. Proceeded to put everything else back together, and then i started it to drive it, and i had a tick/ tapping noise, as can see here : View: https://youtu.be/avPb01yObDI

So I was told by a mechanic it was just a lash adjuster. So i tried to drive it back to my house, and it made it about a mile then died. On the side of the highway, I diagnosed it to be timing chain tensioner. So i got it to a garage, put new tensioners, guides, and chaines on, and the car fired up. But the ticking was still there! So then i bought lash adjusters, swapped those out, and the ticking was quieter, and would go away with RPM. Well i quit messing with it, and came back a few days later, and the car fired right up, and had absolutely no noise at all. So, i drove it, and it would be intermittent. But the car ran great! I was about to pull back into driveway and it died and now will not fire up. I pulled the valve cover, and here is what i found :
View: https://youtu.be/xghlFIQ1exY

View: https://youtu.be/S426AWsWPwQ


So, what could be causing that follower to be loose? The follower bearings are fine, already checked that. If the valve is stuck, could it be bent? Mind you, the machine shop said the guides look fine. I don’t know what to do!
 
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wmburns

SN Certified Technician
Aug 14, 2009
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Houston Texas
Just wondering. Were the heads shaved at all?

Did you degree the cam prior to first run?

My vote. It's well known that putting PI heads on a non-PI bottom end raises the CR by a full point. It's also well known that any cam larger than stock needs to be degree'ed due to the reduced piston to valve clearance the chosen combination has. In fact it was always my understanding that a stage 3 cam is considered to be too much cam for this combination even if the cam is degree'ed.

To me one of the theories should be a bent valve that is being held open. A compression test on that cylinder could help rule this theory in/out.

OBTW, that motor did sound great during the first start up!
 

K7Stang

New Member
Nov 21, 2018
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1
21
Ohio
Thank you
Just wondering. Were the heads shaved at all?

Did you degree the cam prior to first run?

My vote. It's well known that putting PI heads on a non-PI bottom end raises the CR by a full point. It's also well known that any cam larger than stock needs to be degree'ed due to the reduced piston to valve clearance the chosen combination has. In fact it was always my understanding that a stage 3 cam is considered to be too much cam for this combination even if the cam is degree'ed.

To me one of the theories should be a bent valve that is being held open. A compression test on that cylinder could help rule this theory in/out.

OBTW, that motor did sound great during the first start up!

Thank you for your reply!! The reason i did not degree the cams is because i ran the same exact cams on the NPI set up, and it ran awesome. Also, if it were a PTV issue, wouldn’t it be constantly happening? Also, I didn’t have a compression tester so i just used a shop town over spark plug well and it had some compression, not a ton, but some. I just am wondering if the valve could be stuck? If it is stuck does that mean its bent? Car turns over fine. Almost turns over too fast.. i just don’t want to pull those heads again. Long tibe headers makes it a *****
 

wmburns

SN Certified Technician
Aug 14, 2009
5,871
512
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Houston Texas
One of the things that I don't think is being fully appreciated is the difference between static PTV clearance and dynamic PTV clearance. It's very possible to have enough clearance to turn the motor over by hand but not enough to cover all operating modes.

I don't know for certain that PTV is your problem. However I'm a big believer in Occam's Razor. Given what is well known about the combination, Occam's razor might suggest that the simplest answer to the problem is PTV contact.

At the very least it seems to me that the burden of proof would be to prove that PTV contact did NOT occur.

Occam's razor
https://en.wikipedia.org/wiki/Occam's_razor
 

K7Stang

New Member
Nov 21, 2018
10
0
1
21
Ohio
One of the things that I don't think is being fully appreciated is the difference between static PTV clearance and dynamic PTV clearance. It's very possible to have enough clearance to turn the motor over by hand but not enough to cover all operating modes.

I don't know for certain that PTV is your problem. However I'm a big believer in Occam's Razor. Given what is well known about the combination, Occam's razor might suggest that the simplest answer to the problem is PTV contact.

At the very least it seems to me that the burden of proof would be to prove that PTV contact did NOT occur.

Occam's razor
https://en.wikipedia.org/wiki/Occam's_razor
I definitely would agree that the burden is on me to prove otherwise. It just doesn’t make much sense to me that the car would idle for a good amount of time, reaching operating temperature and would be fine. It was after there was a load on it. Also, i did a pull in it when the noise was gone, and it ran fantastic. Wouldn’t PTV be consistent, rather than intermittent? I’ve also read a lot on valve guid issuse. I am curious as to if the valve is stuck in the guide? Sounds to me like i’m going to have to pull the intake and inspect the valves
 

wmburns

SN Certified Technician
Aug 14, 2009
5,871
512
204
Houston Texas
I definitely would agree that the burden is on me to prove otherwise. It just doesn’t make much sense to me that the car would idle for a good amount of time, reaching operating temperature and would be fine. It was after there was a load on it. Also, i did a pull in it when the noise was gone, and it ran fantastic. Wouldn’t PTV be consistent, rather than intermittent? I’ve also read a lot on valve guid issuse. I am curious as to if the valve is stuck in the guide? Sounds to me like i’m going to have to pull the intake and inspect the valves
What IF the valve is stuck in the guide because that is where it was bent?

Also consider that the current operating condition of the motor could have been altered by the "event" itself. For example. If the value is bent and not sealing well this would cause a power drop in that cylinder.

Or what if the roller follower was also bent/deformed during the event! Now the bent roller follower is not opening the value as far as it originally did. That theory might fit the evidence better as it explains the extra play between the roller follower and lash adjuster.

I would buy/rent a compression tester and start there.
 

K7Stang

New Member
Nov 21, 2018
10
0
1
21
Ohio
What IF the valve is stuck in the guide because that is where it was bent?

Also consider that the current operating condition of the motor could have been altered by the "event" itself. For example. If the value is bent and not sealing well this would cause a power drop in that cylinder.

Or what if the roller follower was also bent/deformed during the event! Now the bent roller follower is not opening the value as far as it originally did. That theory might fit the evidence better as it explains the extra play between the roller follower and lash adjuster.

I would buy/rent a compression tester and start there.

Okay, i’ll rent or buy one and test the compression. I’ll let you know what i find. Probably won’t be until tomorrow or Friday because of the holiday. Thank you for your Input, i do appreciate it. Has been very stressful and exhausting
 

K7Stang

New Member
Nov 21, 2018
10
0
1
21
Ohio
Well no good news. The tail of the spark plug in the number one cylinder was collapsed and touching the electrode and the compression rations were as written in the picture. One of the cylinders that read 0 had what appeared to be a puddle of oil in it. Probably going to need a motor. What do you guys thing?
 

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K7Stang

New Member
Nov 21, 2018
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Ohio
For anyone who has a similar issue, mine ended up being valve guides. 2 of them had broke and fallen into the engine and completely tore it up.