Chain Rattle 800 miles after doing timing job....

[S20Workstation4]

Hello All,

2010 Ford Expedition EL XLT 4x4 - 219,000 Miles

I did a full timing set back in August 2022 with all Ford OE Parts, except the Melling M340HV Oil Pump. I've only driven the vehicle about 800 miles since August, and I just noticed the rattle happening again.
However, the rattle lasts for only about 1/2 a second, it is a very small rattle and doesn't last like the rattle normally does, which is 1-2 seconds. It defintely sounds like the timing chain.

I faced a camera towards the passenger side chain and recorded, while I turned the engine over by hand. The chain gains slack, then becomes tight, then gains slack again, then becomes tight again... it does this as long as I keep turning the engine over by hand. Is it normal for the chain to gain slack and then become tight again, doing it over and over again?


Could it be a tensioner that has gone bad already? I don't know how the tensioner could blow this quickly in only 800 miles...


Thank you,
-Joseph

 

[bodabdan]

You're probably feeling the valve springs pushing against the cam lobes. Without engine oil pressure chains will be looser. If it were mine I would pull valve covers to look at all of it.

 

[rwmorrisonjr]

I had the same thing happen; the RT side tensioner blew out. Replaced with the Melling cast tensioners, no issues since.

 

[S20Workstation4]

Thank you for your reply. I started it about 1 hour ago after a full day of sitting, and there was no rattle. You are probably right about the valve spings. I'll take a look into the valvetrain area soon.

 

[Vincent Vega]

@S20Workstation4 I have the same issue after replacing my tensioners with Melling cast iron (in addition to new chains, guides, oil pump). When I get myself psyched up I will pull the valve covers to evaluate the chain tension and condition of the roller followers and lash adjusters. FordTechMAkuloco used to say that the Melling cast iron hold up better than the OEM tensioners, but a more recent video he says the Melling tensioners somehow can cause chain stretch. Good luck and let us know what you find and I will do the same. Alot of other things I would rather be doing that pulling this thing apart again...

 

[Trainmaster]

Are you sure your oil filter isn't just leaking down? Try changing the filter first, using a Motorcraft filter, of course. Maybe the silicone check valve isn't holding.

 

[S20Workstation4]

It could be the oil filter, I've been using the Fram XG2 for almost all of its life. I did a transmission service on it recently, and I haven't noticed the rattle at all.
I have to change the oil in Mid-June, so I will be changing the filter then.