5.4L 3V Crank Trigger Wheel Damage

[mchan68]

I have an '07 F-150 5.4L 3V diag'd by our tune down department needing a bank #2 phaser and VCT valve body. Just as I was getting ready to re-install the front cover, I noticed this:

Has anyone ever come across this before? I checked for play on the crank keyway, and clearance on the back side. It doesn't appear that the chains show any signs of damage or evidence of contact. Engine oil is very clean, much like that it was maintained regularly. Believe it or not, this truck came in with the engine running relatively smooth.

[Brad Clayton]

You got a practical joker in the shop f'en with ya?

[mchan68]

I wish it were that. I checked around the front cover, timing chains and anywhere I could think of, where the trigger wheel could potentially contact without finding anything. This engine has never been apart (at least not according to OASIS anyways), so I'm stumped. Got it all back together and it's running fine for now.

[Shlep]

Just had the same thing on an 06 Expedition, 90,000kms or so... right chain guide had about an inch or so broken off and forcing the chain into the backside of the trigger wheel.

[mchan68]

Just had the same thing on an 06 Expedition, 90,000kms or so... right chain guide had about an inch or so broken off and forcing the chain into the backside of the trigger wheel.

I checked ALL chain guides and none of them were broken.

[Shlep]

Thrust bearing?? dunno what else to say Mike....

[mrbudge]

The front chain will hit the trigger wheel if they rattle on startup before they get oil pressure. The old engines had ratchets on the tensioners so there was no problem with them. Crank one over with the valve cover off and watch the tensioner do the chicken until oil pressure hits it. There are probably wear marks on the inside of the chain cover also. If you are working on the cam drive on one of these engines for any reason I would suggest that you check the cam journals when the valve covers are off. If they are scored up they will cause all kinds of hard to diagnose vct codes and noises due to oil pressure loss. It does not seem to affect base oil pressure so a base oil pressure test is not going to indicate a problem.

[mchan68]

The front chain will hit the trigger wheel if they rattle on startup before they get oil pressure. The old engines had ratchets on the tensioners so there was no problem with them.

You're referring to the older cast iron ones that you had to hold the lock tab back when compressing them, as opposed to the newer plastic ones right? Good observation.

Originally Posted By: mrbudge

Crank one over with the valve cover off and watch the tensioner do the chicken until oil pressure hits it. There are probably wear marks on the inside of the chain cover also. If you are working on the cam drive on one of these engines for any reason I would suggest that you check the cam journals when the valve covers are off. If they are scored up they will cause all kinds of hard to diagnose vct codes and noises due to oil pressure loss. It does not seem to affect base oil pressure so a base oil pressure test is not going to indicate a problem.

That's good to know. I get this feeling I'll be seeing more and more of them.

[Adam_Dodson]

usually damage to those cam journals leads me to find a Fram/Penzoil/Quakerstate or any of those other Honeywell brand full of cardboard peice of crap filters under the truck as well...

[DamageINC]

For what it's worth, I believe you can use the older-style tensioners on these engines and they work just fine. It's common practice on the performance engine builds, at least I know for the built 4-valve engines that recieved the new-style tensioners back in '03 from the factory. Any time someone blows up their Terminator engine, the rebuilds usually have old-style tensioners on them.

 

I am not 100% sure they'll work on the 3-valve engines but the short blocks are almost totally identical so I'd imagine it'd transfer over just fine.

 

Dave