How to: SOHC V6 Timing Chain Inspection & Repair

[laker82]

The noise is coming and going with no rhyme or reason. Maybe there is a blockage to the front tensioner. I will check it. I'm just glad it is running again.

Are you seeing any oil pressure changes? My memory is there is a bypass built into the oil filter housing. I really do not know why I think that. Mostly asking the question.

Do you have the old tensioner? It would not be the first new piece that was worst than the old one.

 

[BobRob]

You're probably using a standard balancer puller with the diameter of the center bolt exceeding the diameter of the crankshaft. The result is the puller is trying to pull apart the balancer instead of trying to separate it from the crankshaft. Read post 3 of this thread.



I don't understand. The oil pump is driven by a shaft, not a chain.
View attachment 87229
Dropping oil pressure for a few seconds should not have caused bearing damage. The engine runs that long without oil pressure every time it is started.

I'm guessing he's looking at the balance shaft chain.

 

[laker82]

damienlike,

If you pick a picture from page 1 or post #55 on page 2 and describe the problem from a specific picture you will get a better answer.

 

[damienlike]

Sorry guys, got turned around on what I was looking at. Post #5 , top picture, the small chain that goes from the crank gear and down to the left. Not sure what that would be.

 

[laker82]

Post 55 is pg 3. shows balance shaft with both oil pans removed. Removing the torx bolt should let the gear come off easily.
The center chain, main chain, drives the jack shaft located between the heads. The rear of that shaft drives the oil pump drive and the right timing chain.

 

[2000StreetRod]

balance shaft sprocket

Do not remove the balance shaft sprocket retaining bolt!

Contrary to what is shown below I think the sprocket is not keyed and it's position is determined by the factory. There are alignment marks (A) on the sprocket to match with a mark (B) on the balance shaft housing .

If you remove the sprocket retaining bolt it will be difficult to determine the correct position of the sprocket when reinstalling it. The balance shaft is actually below the sprocket and rotates at a different speed than the sprocket due to a set of gears behind the housing front. It also has an alignment mark (C).

 

[rb142]

The pressure drop may have been due to debris in the pickup, or even just engine speed dropping. Shouldn't be a problem.

Agree with StreetRod about the damper puller. The tip has to be small and long enough to reach down the hole. Many people use the loosened crank bolt to push against.

 

[laker82]

I was reading into the story that the balance chain was what broke. Removing the guide and the four bolts that hold the balance assembly would probably let you change the chain. The timing would already be toast if the chain broke.
Retiming would require a loose gear or a lot of trial and error to get it right.

 

[2000StreetRod]

restoring balance shaft timing

As long as the balance shaft sprocket retaining bolt has not been loosened it is possible to restore the balance shaft to crankshaft timing by aligning the marks. See Balance Shaft Timing Procedure

 

[ef2764]

Kabloowey

Do you have the old tensioner? It would not be the first new piece that was worst than the old one.

So my drivers side cam cassette gave up the ghost. I was driving home the other day the diesel knocking noise got a lot louder and I lost oil pressure. when I got it home and pulled the pan the oil pump pick up screen was filled with plastic shavings. The cassette is a piece I replaced in October maybe 2000 miles ago. there is no way this should have failed so quickly. When I pulled the cassette out it had deep grooves in the plastic almost like the chain had too much tension on it or the plastic was not hard enough. I used a Cloyes timing set that I bought from Rock Auto. Has anyone else heard of similar problems with these replacement parts?

 

[2000StreetRod]

test before installation?

Cloyes timing chain kits have a pretty good reputation vs the price. Did you test the hydraulic tensioner before installing it? I oil the tensioner and then compress and release the piston with my thumb to make sure it moves smoothly and doesn't stick. Cheap aftermarket tensioners have been known to seize. If they seize in the fully extended position the cassette guides breaks. If they seize in the retracted position the chain can slip.

I'd contact Rock Auto to see if they will replace it at no cost to you.

I had 150K miles on my stock front cassette guide when I replaced it. Only about 10% of the "plastic" chain contact surface had worn away.

 

[ef2764]

Agreed

Cloyes timing chain kits have a pretty good reputation vs the price. Did you test the hydraulic tensioner before installing it?
I'd contact Rock Auto to see if they will replace it at no cost to you.

I had 150K miles on my stock front cassette guide when I replaced it. Only about 10% of the "plastic" chain contact surface had worn away.

I agree about Cloyes reputation. I have reached out to them for Warranty. The tensioner was new with the Cloyes Kit and moves smoothly. Also my cassette guide that I pulled out showed similar wear to what you describe. Barley any compared to what happened to the new one I installed.

 

[ef2764]

Cloyes Tech help line

So I talked to Cloyes tech line the other day and he was extremely knowledgeable , even able to diagnose a cracked chain without looking at it. Apparently I am having left tensioner issues which caused the chain to slap around (probably the source of the noise) and eventually wear and break the guide and chain. My question is how do I test for oil pressure at the tensioner. I see the galley plug that is right there but what feeds this? Where would I start to look for a blockage? I tried spraying brake cleaner down into the port last night and more of it came back at me than went into the hole. Any thoughts?

Thanks

J

 

[2000StreetRod]

replaced cassette

Did you replace the entire cassette (guide, sprockets & chain) or just the guide 2K miles ago? If the chain was not replaced, is the Cloyes tech saying that the chain was cracked due to a broken guide before and broke the new one also?

 

[ef2764]

Cracked chain

Did you replace the entire cassette (guide, sprockets & chain) or just the guide 2K miles ago? If the chain was not replaced, is the Cloyes tech saying that the chain was cracked due to a broken guide before and broke the new one also?

I replaced the entire cassette. However this cassette was perfectly fine before I replaced it. The rear cassette is the one that originally failed.

 

[2000StreetRod]

seems unlikely

I replaced the entire cassette. However this cassette was perfectly fine before I replaced it. The rear cassette is the one that originally failed.

I think you're saying that the rear cassette failed 2K miles ago but you replaced both the rear and front cassette. If so, it seems unlikely unless the chain was defective that it cracked in 2K miles for any reason. The chains are very strong. The sprockets are even stronger. Only the guides are weak.

 

[ef2764]

Agreed

I think you're saying that the rear cassette failed 2K miles ago but you replaced both the rear and front cassette. If so, it seems unlikely unless the chain was defective that it cracked in 2K miles for any reason. The chains are very strong. The sprockets are even stronger. Only the guides are weak.

Everything you said here is correct. However I have a cracked chain which is what shredded and broke the guide. Talking with the Cloyes Tech rep, the reason the chain is cracked is because it was slapping around due to a tensioner issue. My issue now is figuring out why I have tensioner issues before installing a new chain and having the same issue over again.

So my most important question is where is the oil for the tensioner coming from? How do I trace back and find an obstruction if there is one? I tried spraying brake cleaner through the port in the head and it doesn't appear to go anywhere (more of it sprays back at me than goes in the hole). Thoughts?

 

[2000StreetRod]

tensioner oil supply

The oil enters the tensioner via the port shown below (right tensioner but left is similar).

The matching feed port for the tensioner port encircles the tensioner port so the clock position of the tensioner doesn't matter. Just make sure the port in the head is clear. The oil gallery that feeds the port in the head is located below the plug shown below with a socket drive and bit applied.

The volume reducer (restrictor/"pencil") in the 00M12 kit shown below is accessed by removing the Torx head plug.

The Torx head is easily stripped so if you decide to remove the plug: thoroughly clean the top; apply PB Blaster or equivalent to the plug and give time to soak in; using a small hammer tap the Torx bit end or the socket drive to make sure the bit is seated in the head of the plug; apply pressure to the socket drive to prevent the Torx bit from "backing out" when torque is applied.

I'm still skeptical about the chain cracking due to a failed guide or tensioner. Unlike the rear cassette there is no post for a loose chain to strike. The chain "plastic" contact surface has very little force on it from the chain. The 3rd generation valve covers are composite material instead of metal so if the chain strikes them it won't wear. I think the only way the left timing chain can contact metal surfaces is if the tabs that hold the plastic contact surface break and the entire plastic section falls away exposing the metal support.

 

[MNT2007]

2007 Mercury Mountaineer 4.0L

After quite some time of not being overly concerned by the one-second timing chain sounding rattle at cold startup, I suddenly have developed a loud rattle that stays from startup to full operating temperature. It seems to be coming from the front middle or left (drivers) side. After spending many many hours reading everything I can find on here, I am pretty sure I have a guide or tensioner problem, either the primary chain tensioner or the driver side chain guide. I guess its also possible it could be the balance to crank chain guide or tensioner, but that doesn't seem to sound too common. No noise from the back right side.

I'm getting close to beginning the tedious task of inspecting and R & R-ing the necessary parts as so excellently laid out here by 2000StreetRod and others, but thought before I start, if anyone might have had any experience with a later year 4.0 like mine, and be able to offer any additional words of wisdom, it might be helpful.

The car starts right up with no problem. I haven't been driving it since this louder rattle started. But I have let it warm to normal operating temperature, and when I bring it up to between 2000-3000 rpms, it seems to quiet down some, but seems very loud when I let off the throttle; in fact, I feel the need to ease it back down to idle speed. If none of the chains have jumped, it would seem a good thing to keep it that way.

I have run it a few times this way (let it idle), and have occasionally developed an P0300 and P0301 code (random misfire and cyl 1 misfire). I have cleared the codes and either they have not reappeared, or then have then reappeared after a few times of this starting from cold and bringing to warm idle cycling...not every time. The engine seems to run pretty good other than the rattle.

Despite all of my research, while it sounds as though Ford enhanced some of the guides and tensioners, maybe in around 2002 or so??, I haven't been able to find anything stating specifically what year(s) these changes were made, or if there were any others later. I do know about the improved primary chain tensioner, and I believe the metal reinforcement of the left side guide and maybe the right side also.

Also, I haven't seen anyone on here indicating they have had this issue with anything really even close to as recent a model year as mine. I'm thinking maybe 2004 was the latest model year where I have read on here about someone needing to address this timing chain issue. So, I feel like I should be a little surprised that I'm dealing with this at 145K on the odo.

There were some apparently minor changes to this engine that I'm guessing may have corresponded to the timing of some slight body modifications that occurred in the Explorer and Mountaineer beginning in model year 2006 and later (one-piece tailgate/hatch; redesigned dashboard; automatic trans shifter moved from the steering column to the floor; new seating/console design, etc.). I also have a '99 Explorer 4.0, and my '07 engine compartment is different in a few ways, including a redesigned upper intake manifold, the oil filler hole is on the passenger side valve cover instead of on the driver side; the engine coolant overflow/recovery tank is in the front versus the old being on the passenger side fender; the 07 no longer has the trans dipstick. I think there are a few other minor modifications but I believe the engine is largely the same and also with regard to the design of the cams, timing chains, tensioners, guides, etc. Am I right?

Also, some of the replacement parts and the OTC tool kit seem to limit the applicable years to those prior to my 2007; I'm not sure how much sense this makes.

Also, being AWD, mine would have a balance shaft, correct?

Any thoughts or experience with this later version would be greatly appreciated!!

My specifics:
2007 Mercury Mountaineer
4.0L
AWD
145,000 mi

Thanks,
Jeremy

 

[2000StreetRod]

improvements

Greetings Jeremy,

To my knowledge there were no camshaft timing chain related improvements after those incorporated in the 2002 and later models. This applies to all makes -Explorer, Mountaineer, Ranger and Mustang. I don't know why the Mustangs aren't experiencing the failures as frequently as the Explorers. It may have something to do with the lower weight and frontal area and rear axle gearing of the Mustangs.

There were changes to the block or head around 2004 that make it extremely difficult to replace the front (left) cassette guide assembly with the head on. You'll find out if you have enough clearance when you attempt to remove the old cassette guide assembly. The newer left cassette assemblies can be disassembled (the pivot pin has a keeper instead of being pressed) and some members have been able to disassemble the cassette guide assembly and install it without removing the head.

Yes, you should have the balance shaft. When that tensioner fails (I'm not aware of it ever being improved) the chain can get pretty noisy. The balance shaft chain being loose should not result in any misfires or incorrect camshaft timing. If the primary (crankshaft to jackshaft) chain tensioner has failed it would affect timing of both banks and there should be corresponding misfires. Since your consistent misfires are on cylinder 1 (front passenger side) then a failed rear cassette guide is more likely. Rattles bounce around the inside of the engine making location of the source very difficult. I listened to my engine using a mechanic's stethoscope and a length of flexible tube (pipe insulation). I was convinced my front (left) cassette guide had failed but when I visually inspected I found a failed rear cassette guide and a failed primary chain tensioner.