99 4.0 SOHC - Lifter/Lash Adjuster Noise

[LuketheDuke]

So I am fairly sure that the diesel noise on my explorer is a worn out lash adjuster that's knocking, rattling, or what have you. I have a mechanic lined up that thought he could do it fairly cheap ($200-400) but before I have that done, is there anything I can do to fix it at home? Once in awhile, it will go away entirely. I have heard people talk about installing Oil Filters with backflow prevention as well. Suggestions?

 

[SoNic67]

All the Motorcraft filters have anti-drainback valves on them. But they won't help the noise while engine is running, only at start-up.
You can adjust the adjusters, but they will never be fixed - unless you remove and replace them.
Some oil flush or cleaners claim that help, but... they didn't in my case.

 

[LuketheDuke]

Ok, so just to be sure, this IS likely the adjusters right?

 

[drdoom]

Usually the timing chain in that engine.

 

[boominXplorer]

Probably a timing chain issue. I have done over 20 timing chain jobs on 4.0 sohc engines and only once did I have an issue with a lash adjuster.

 

[2000StreetRod]

low estimate

I suspect either your mechanic is unfamiliar with your engine or just wants to get the vehicle in the shop with a low estimate and then end up with a major job and expense to you. The lash adjusters are actually hydraulic cam followers with no mechanical adjustment. If your engine sounds like there are marbles rattling around inside the block then I agree with the previous posts that you're hearing timing chain rattle due to a failed cassette. When your mechanic tears into the engine he will notify you that and give you an estimate of $1500 to $3000 depending on which cassette(s) and tensioner(s) have failed and if OEM or aftermarket replacement parts are used. I suggest you ask him if he's ever replaced the rear cassette on a Ford SOHC 4.0L V6 and if he has the OTC-6488 timing tool kit to time the camshafts. Then ask him what that will cost before allowing him to start any work.

 

[LuketheDuke]

Well that's bad news on my end then. The sound is predominantly on the rear right side of the motor (if you're facing the compartment with the hood open).

 

[2000StreetRod]

Timing chain rattle resolution process - SOHC V6

Timing chain rattle resolution process - SOHC V6

There is a cassette on the passenger side rear and the driver side front. Search for you tube videos of timing chain rattle to compare sounds. Maybe your exhaust gasket is leaking. Try to locate the source of the sound with a flexible tube.