Passenger Side Valve Train Noise (4.0L SOHC) VIDEO

[swshawaii]

First video. Excuse the camera "work", I needed three hands. Posted in the 1995-01 sub forum for visibility. Rattle is intermittent and only happens at idle speed when the engine is at operating temperature. NEVER rattles at start up, or at the known 2500-3000 RPM range indicating timing chain guide issues. New rear hydraulic tensioner has been primed and installed with the OE Ford (7U3Z6K254A) replacement. I've read it could possibly be cam follower/lifter noise, but that sounded more rhythmic, faster, and a sharper ticking sound from the videos I've heard. I understand removing the valve cover is the only way to be sure, just want to have an idea what to expect when I open it up. Stethoscope rod touching the rear of the valve cover with one ear piece touching the built in camera microphone begins at 32 seconds. ST has 78,000 miles, is driven very gently using only NAPA full synthetic (Valvoline Synpower) 5W-30, and FL-820S filters replaced at less than 4000 mile intervals since I drive less than that every year. Never believed in or used engine oil additives, but a $7 bottle of Rislone may be worth a try. Thanks in advance, I'm hoping for the best.

 

[donalds]

Sounds like a belt tensioner remove the belt and run it for under a minute see if it is belt related

 

[swshawaii]

Thanks Donald. Definitely not the serpentine belt tensioner or any pulley. Belt tensioner is almost new with no movement,
and all the pulleys are smooth. That's encouraging coming from you. Almost wish I bought the Polaris tensioner from the great "4.0 SOHC Timing Noise" thread you're so involved with.

 

[donalds]

I haven't used the Polaris tensioners yet because I have a pre oiler
I don't think the Polaris tensioners will help with noise when the engine running as the hydraulic ford tensioners are already pumped up unless they are faulty witch you said they are new

I don't think it's a timing issue just my 2cents

Here is a similar thread give you an idea of what's normal
And some examples of failure of timing components

Rattling noise

 

[swshawaii]

I've isolated the rattle below the rear of the passenger valve cover. If I move the stethoscope probe to the front of the valve cover it's much quieter. Trying to be optimistic, but the noise is coming from the rear timing guide area. Need to get valve cover gaskets and find out. Thanks for your idea of trimming the inner fender liner for easier rear tensioner access. Nice to get a straight shot at that stupid low profile tensioner head without universals and slipping. When knuckles meet the upper control arm, the UCA always wins.

 

[allmyEXes]

Thanks for your idea of trimming the inner fender liner for easier rear tensioner access. Nice to get a straight shot at that stupid low profile tensioner head without universals and slipping. When knuckles meet the upper control arm, the UCA always wins.

Your Welcome !

 

[swshawaii]

^ Oops! Sorry allmyEXes, must give credit to YOU.

And for anyone that hasn't seen this great thread:
4.0 SOHC Timing Noise

 

[allmyEXes]

Curious...Did you trim or drill a hole ?
By the way, Thank you swshawaii, donalds and others with experience with this issue on my V-6. I feel like one of the lucky few that was able to fix with the replacement tensioner.

 

[swshawaii]

Thank you. If your success continues with the Polaris manual tensioner, you and 410Fortune may have answered the prayers of many 4.0L SOHC owners getting up there in mileage. There have also been many threads regarding the need for all metal timing guides with synthetic faces, but that has gone nowhere with aftermarket suppliers including Dorman.

Initially used a small hole saw to cut the plastic inner fender liner but was a little off and decided to cut using heavy duty shears then sanding the sharp edge smooth. As you mentioned, the full length soft rubber apron covers the trimmed area completely. Also nice to have clear access to the #3 "spark plug from hell" with the tire cranked all the way left.

.

 

[david4451]

It does sound like metal to metal contact. The place could be where the traction side all pastic guide is held at the top by a torx headed bolt. That would mean that the chain is contacting this bolt, caused by the all plastic guide being broken at the bottom where it pivots with the reinforced slack side tensioner.

I'd suggest you don't start your engine again or the traction side (if broken) can be pulled in to the jackshaft sprocket and jump time. You will see if this is the problem as soon as you remove the valve cover.

 

[allmyEXes]

Thanks to Jamie for posting the pic of the Sparks type tensioner. I have not seen the part in person that the tensioner pushes against and then the chain runs against the other side ? Could a CNC program be written and machine something out of a real tough plastic type material like DELRIN ?
Polyoxymethylene - Wikipedia

 

[swshawaii]

It does sound like metal to metal contact. The place could be where the traction side all plastic guide is held at the top by a torx headed bolt. That would mean that the chain is contacting this bolt, caused by the all plastic guide being broken at the bottom where it pivots with the reinforced slack side tensioner.

I'd suggest you don't start your engine again or the traction side (if broken) can be pulled in to the jackshaft sprocket and jump time. You will see if this is the problem as soon as you remove the valve cover.

^ EDITED- You mean the Torx bolt in the top pic with the red arrow? My noise is intermittent and occurs maybe 1/3 of the time when idling with the engine warm. Never at start up when cold. I REALLY need to remove the valve cover, no other way of knowing. Link below:

Torx bolt with red arrow pic (Post #6)
How to: - SOHC V6 Rear Cassette Replacement

 

[allmyEXes]

where is this picture with the red arrow ?

 

[koda2000]

where is this picture with the red arrow ?

This red arrow?

 

[allmyEXes]

Is this a correct picture of the guide ?

 

[david4451]

That's the bolt I'm talking about, the other photo is of balance shaft guide which is not related to rear cassette function.

As in photo above with red arow it will be immediately obvious if this is the problem, once valve cover is removed.

You have obviously cared for your ST and these engines do make some intermittent strange noises. I've just rebuilt mine and it ran perfectly and quietly for 200 miles. Started it one morning and I'd got a noise comming from the drivers side front that sounded like the timing chain rubbing on something. Once warmed up the noise went away! As you may guess I was really really brassed off after such a lot of work.

It was not the timing chains but the vacuum line from the front of drivers side inlet manifold attachment to the vapour canister purge valve (under battery). It was making a chuff chuff noise and when I squeezed the line the noise went away. It was just by luck I found out what it was, touching and fiddling with everything in that area.......

 

[allmyEXes]

Thanks Y'all, You all and everyone else involved in this exploratory research. I do not know the anatomy of these engines firsthand.