Timing chain tensioners Seal leaking, start up rattle

[MetalSlug]

Good morning, this start up rattle on my 03 Mustang cobra been going on for few years. If I could start after it sat for month. It's will have this clack clack or rattle for half a second.

Some cobra owner suggest ongoing back to FL820s

Current I'm using Mobil 1 5w30 with Carquest premium

Some suggest liquid moly m0s2 anti friction

Some said its normal since it sat for long time

 

[Kira]

I see the "620 whp" in your signature, but which engine?

See if the "Clear Flooded Engine" method works with your vehicle.
i.e. Turn key to ON, Floor the accelerator (this shuts fuel delivery and spark in some setups), Crank the engine for 2-3 seconds to get the oil pressure up.
Release things then start normally.
Your start-up rattle may vanish.

 

[MetalSlug]

It's Dohc 32v 4.6. It's made 690 now.

 

[SC Maintenance]

Sounds like your hydraulic lifters bleeding down after a month? Or just the ADBV doing so. Or both.

 

[OVERKILL]

I see the "620 whp" in your signature, but which engine?

That would be the iron block 32V factory supercharged 4.6L Modular, sounds like he either has an aftermarket blower or a turbo kit on it.

 

[OVERKILL]

Good morning, this start up rattle on my 03 Mustang cobra been going on for few years. If I could start after it sat for month. It's will have this clack clack or rattle for half a second.

Some cobra owner suggest ongoing back to FL820s

Current I'm using Mobil 1 5w30 with Carquest premium

Some suggest liquid moly m0s2 anti friction

Some said its normal since it sat for long time

It's probably either HLA bleed-down as @SC Maintenance referenced, or the timing chain tensioner is slackening off, so you get a bit of chain whip until it sees oil pressure. No additive is likely to help here, and I doubt there is any harm being done. Have the chains and guides ever been changed? How many miles are on it?

 

[PontiacHO]

Not relevant here but…my 2003 F150 4.6 would rattle on start up with any filter except for a Motorcraft filter.

 

[MetalSlug]

Sounds like your hydraulic lifters bleeding down after a month? Or just the ADBV doing so. Or both.

I think this is

 

[MetalSlug]

Not relevant here but…my 2003 F150 4.6 would rattle on start up with any filter except for a Motorcraft filter.

This what cobra forum told me but we all know how messy inside of FL820s is

 

[freakazooid52]

Where the primary timing chain tensioners ever replaced with the cast iron ones? The plastic ones blow out the gasket which starves top end of oil also plastic tensioner doesn't ratchet and hold themselves tight like the cast iron ones do and start up rattle is common

This is a Ford modular problem effects all sohc or dohc engines

 

[bullwinkle]

At least yours takes a month-the MGM 4.6 2V in my sig does it after 2-3 days! After I retire…