Timing Chain Tensioner 2004 SOHC

[searay175]

New to the forum. I have a 2004 Explorer Sport Trac, bought it new and it has been one of the best vehicles I have ever owned.
I recently noticed that I hear a light tapping noise when I first start the truck up in the morning, which seems to quiet up once the vehicle has warmed up. I’m thinking it’s related to the timing chain. I can hear the sound most from the drives side wheel well. Once the truck is warm I can only hear a faint noise and only hear it when the truck is at idle in gear. I’ve never heard the noise above idle speed. I currently have 86,000 miles on the truck and have always used a motor craft filter, 5W-30, and changed the oild every 3K miles. I’m really hoping the internal tensioners aren’t bad at this point…..

I was going to start with replacing the hydraulic tensors on the front of the left head and on the back of the right head. The rear tensioner bolt seems like a straight forward job. From digging through the forum I saw a few posts that say to front tensioner bolt can be replaced without removing the intake manifold as you did in earlier versions of the 4.0 SOHC. I was wondering if anyone has swapped out the front tensioner and could point me in the right direction of removing the both without removing the intake manifold or the thermostat housing.

Thanks for the help
-Shawn

 

[imp]

Am asking myself why would the noise occur when eng. cold, and go away when hot? Logically, my little mind works this way: cold oil is thick, it cushions things with too much clearance, thus tending to prevent noise when cold, as oil gets hot and thinner, noise should become worse, not go away or lessen.

The timing chain itself, when cold, is slightly shorter than when hot, so given whatever force is left which the tensioner(s) is applying, as the chain gets hot (slightly longer), clearance should increase, causing noise to do likewise.

I may be all wet with my thinking here, but messing with the tensioners may be a waste of time, considering the relatively low mileage on your engine.

Two things come to mind immediately regarding cold-start engine noise:
1. Excessive clearance in bearings allows noise for a very short time, until oil pressure builds up to "cushion" the clearance. Definitely ruled out in your engine.
2. Something called "piston-slap" makes a tapping noise for a much longer time, until the pistons become hot, and differentially expand in their cylinders, at which time the noise ceases. This would seem a better bet, to me, to explain the type of noise you are experiencing, based on the limited amount of information to go on. imp

 

[coco944x4s]

its a hydraulic tensioner so it uses oil pressure to work properly. Cold thick oil pumps slower and harder than warm thin oil.

Timing chain noise is a well known and documented problem with the SOHC 4.0. There is a Ford TSB on it i do believe.

 

[ramonf32]

What do you mean ford tsb on it?

 

[searay175]

Ford issued a technical service bulletin on the 4.0 SOHC, they have had huge issues with the timing chain tensioner system. IMO the engine designers made the timing chain set up the achilles heel of this engine. If you search the forum for SOHC timing chain, you will find a larger number of posts related to this issue.

The thing that drives me crazy with this whole problem is that I can't pin-point the source of the sound. Really doesn't sound like a valve tap, piston slap, or engine knock. I think Ford issues a TSB related to spark knock on the 2004 4.0 SOHC, but I haven't been able to find the details of this TSB anywhere. I think it called for having the ECU flashed.

Right now I have a very low rhythmic taping/ticking noise. I'm hoping the noise gets better with a new set of hydraulic tensors.... Hopefully it will at least by me time in replacing the internal tensioners if they are starting to wear. My plan is to run this truck until the wheels fall off.

 

[chriskramerjr81]

Hey is this a constant noise but quiets slightly when warmer? 05 explorer xlt 4.0 6 cyl. and I just tore mine down yesterday. whether it was hot or cold constant bad tick and it was on the pass side. Ended up being a rocker arm pressed in pin that was seriously falling out of the rocker arm and hitting the inside of the head. Replaced rocker and no tick. Hot or cold. It took an hour and a half but intake/problem valve cover must come off. Its not hard at all so if you decide you wanna tear it down and need a step by step on what to do id be more than happy to help or find my post on aug 20 12:15 am or search my name you should find it. Good luck

 

[ramonf32]

Timing chain problem

I am in a pickle right now! What should be the normal charge to have timing chain and tensioners replaced? If the factory tensioners are a design flaw!Does anyone know if there is an after market tensioner that i could get to replace the defective ones? Also is it true that engine must be pulled to do this work!!! If anyone has any answers / advice it would be greatly appreciated!

 

[2000StreetRod]

tensioner replacement interval

searay175, I recommend that the hydraulic/spring tensioners be replaced every 75,000 miles. I've never seen any recommendaton by Ford but the springs weaken with age. Spring pressure is important when oil pressure is low as at engine start. The timing chains are most apt to slip when oil pressure is low. In my opinion, the strength of brand new springs is too weak.

The only way to accurately determine the status of the timing chain components is to remove the valve covers and inspect: SOHC V6 Timing Chain Inspection & Repair

 

[BAD_FINGER]

Yes, the engine should be pulled to get the timing chain job done right. I know that some people prefer to avoid it and spend just as much time pulling the transmission to get the job done. Here is the good, bad and ugly in a nutshell.... The engine is a timing masterpiece to get it to run perfectly with good gas mileage and emission specs. A tad off on the cam timing and most people might not notice the difference but I would stress attention to accuracy. Timing between the crank, jackshaft, and both cams should be around +-.015 of a degree at a 2" radius (with a dial indicator). Any more than that and YES it will show performance changes on a dyno. The engine can be pulled, and stripped leaving only the rotating short block assembly in tact and the drivers side head on. The passenger side head should be removed in order to remove and install the rear timing chain casette correctly. If it is a 4 wheel vehicle, it will have another chain that drives a balance shaft in the bottom of the engine as well that needs to be changed. TAKE NOTE: All of the head bolts and cam bolts that are removed all have to be replaced from the ford dealer. They are all torque-to-yield bolts and cannot be reused. The reason this is such a must is that ALL of the cam gears and jack shaft gears do not have gear location pins that hold the gear to the shafts like you might expect on a good ol' 350. The gears are held in timing to the shafts simply by the bolt tension they are mounted with. These bolts have to be 2 staged when torqued. They are tightened to spec then turned another 90 degrees past torque to put slight tension stretch on the bolts. The same is the case with the head bolts also.

You will also need a special cam service kit to hold all of the cams and shafts in the exact location when tightening bolts. The kit needed is OTC 6488 and can be found all over Ebay and other places on the internet. To do the job start to finish youll have to get most of what is listed here below:

*OTC 6488 service kit
*Master gasket kit with head bolts
*Replace every chain sprocket bolt
*New rear jackshaft block plug
*Complete timing chain and tensioner kit (Cloyes makes the best one I have ever seen)
*Manual with Torque specs
*red LocTite
*T55 Torx 1/2 drive socket
*T55 Torx Female socket (has a special name I cannot remember lol)
*New flywheel bolts

Depending on the confidence level you may have it can look like a nightmare job to do. I have done 6 of these in the lase 5 months and am in the middle of doing it again as we speak to my wifes Mountaineer for the first time. It is not as bad as it sounds.

 

[2000StreetRod]

removing the head

On the earlier engines it is not necessary to remove the heads to replace the cassettes. On the later engines (possibly during the 3rd generation) there apparently was a change in the block casting or the heads casting because the cassette openings between the heads and the block do not align making removal/installation of the cassettes with the heads in place more difficult.

 

[BAD_FINGER]

......This is a 3rd generation thread so I hope we are all on the same page..