VCT Solenod Replacement?
 

Hey all, I have a 2010 F150 with the 5.4 3 valve with 123,000 miles. I have an intermittent rattle noise that sounds like it is coming from the bottom of the engine. It usually occurs around 1200-1500 RPM and goes away after it downshifts. I know the problems with the engine design. Every mechanic (one dealer and two independent ones that I trust) I have taken it to says it is an internal problem and it will be more cost effective to eventually replace the engine than spend the money to repair it. In researching the problem, I found a TSB bulletin that says the rattle noise may be caused by the VCT Solenoids going bad or clogged. I was wondering if it would be worth replacing them to see if it addresses the rattling issue? I don't think there are any codes since my check engine light is not on so I am not sure if I should replace them. Also, what would be the cause of the rattling sound? Any advice or input would be appreciated. Thanks in advance.

There is a lot of info on this site about this issue...

Here's a starting point: https://www.f150online.com/forums/v8...eshooting.html

Your engine is fixable.

Ok so I have been researching what could be the cause of the rattle. Can I just unplug the VCT Solenoids and see if the rattle goes away without hurting anything? If it still rattles then this should tell me they need to be replaced, correct? Thanks.

No. This is the biggest 'snake oil' advice on the internet. Unplug them "ONLY" leaves them closed (resulting in NO cam retard capability - which SHOULD leave cams at base position ------ _IF_ one isn't 'stuck' partially open / leaking / clogged up - where unplugging them will have no beneficial effect.) They are normally closed by design, and the PCM does not activate them less than 800 RPM or 25% engine load.

It won't hurt anything to unplug them - but it probably won't change anything except cause a DTC. If you have a rattle around 1200 - 1500 rpm, you probably have worn/stretched timing chains and broken chain guides - and are ready for a complete timing job.

F150Torqued, thanks for the feedback. So I did unplug them and the noise went away. Should I even worry about replacing the VCT solenoids and instead get a timing job instead? Thanks.

Well, you are going to have to replace the solenoids anyway - when you do, pull the front cover and inspect the chains, guides, and tensioners.