4.0l Engine Timing Chain Tensioners, Replacement Schedule

[410Fortune]

Pretty sure I read somewhere FORD recommends replacing the upper tensioners on the SOHC engines at 90K miles
Use only Ford parts...the others are JUNK!!!!!

Interesting note here the POlaris Rzr (2014+) uses the same damn tensioner for the timing chain on the overhead cam, tick tick tick on cold start since NEW
There are several aftermarket companies that make a spring loaded or manual tensioner for the Rzr...its the same part.
I put Sparks Racing manual tensioners in our Rzr and no more cold start tick.
I am thinking the same tensioners could be installed in a SOHC.....forget the hydraulic bleed out and pump up...set the manual tension and forget about it....

 

[celticchrys]

Well, I guess I got lucky compared to many. Just found pieces of the cassettes in the oil pan (seal was being replaced), right at 139,000 miles. Had no rattle at all. Left it parked after that, and no other apparent engine damage. So, just had the chains, cassettes, and tensioners replaced. Still cheaper than a new vehicle, but the next one will definitely not be a Ford.

 

[Tech By Trade]

Well, I guess I got lucky compared to many. Just found pieces of the cassettes in the oil pan (seal was being replaced), right at 139,000 miles. Had no rattle at all. Left it parked after that, and no other apparent engine damage. So, just had the chains, cassettes, and tensioners replaced. Still cheaper than a new vehicle, but the next one will definitely not be a Ford.

You are in the same boat as me, except I have gone as far as to say not another domestic. Though current should make a good winter beater when I get around to upgrading. Its acutaly been a pretty reliable vehicle since I did the timing setup.

 

[Paul Fithian]

I would definitely purchase another Ford.

The 4.0 SOHC is not a domestic engine, it was built by Ford in Cologne, Germany. And the 5R55E transmsission was built in France.

My 2001 Sport Trac has 265,000 miles on it, I believe it is the original engine and transmission. Pretty excellent service.

 

[firefly1246]

My 03 has 245k on the original chains/guides. I just took the engine out of mine over the last month and swapped out the timing chains and other goodies while I was there. Just got it running again this weekend.

Couple months ago mine started with a slightly new noise between 2000-2500 rpm when accelerating, based on reading it sounds like this was the rear guide that broke. Based on reading forum, I installed new Motorcraft tensioners after about 1,000 miles. However, when inspecting the original tensioners they didn't appear to be weak. I pulled the fuel pump relay and cranked it over a few times to get oil to the tensioner without engine running. I then started the motor up and immediately got a new very loud metallic rattle. As per others have commented above my swapping of the hydraulic tensioners disturbed the plastic tensioners and broke the front center one. Fourtunelty it broke and wedged itself between the bottom post and the chain so provided "some" tension and didn't skip a tooth. The chain would only make a noise on startup and the chain would hit the metal behind where the broken plastic guide should have been. I only drove the truck a few miles after this event before I pulled the motor.

The project took me multiple days to do. 2 days to pull the motor ~16 hours, 5 days after work to do all the work to the motor (~16 hours), and 2 days to put the engine all back in and do fluids (~16 hours). This was spread out over the course of a month. During this time I had some delays where I had to buy some tools I didn't have or buy items that broke during disassembly. Need to make sure you have torx E sockets for the flywheel bolts and some of the bolts for the timing chain. I also had to clearance the inside of the head for the front driver side timing chain as I had extra casting material and it wouldn't let me remove the old guide. My engine has had the oil changed every 5k miles with conventional 5w-30 since new and the inside of the engine was clean as a whistle. I firmly believe this oil change interval allowed the timing chain guides to last as long as they did. My engine the rear timing chain guide broke, the front center one broke after replacing the hydraulic tensioners, and the front driver side one was in great shape. When I drained the oil I had no chunks of plastic and a barely a hair of metal fillings.

While I had my engine out I did the following:
Timing chains and guides- obviously
New timing cover gasket- have to replace to get to timing chains
New upper and lower oil pan gaskets- upper gasket was leaking
New oil filter housing o rings- was leaking
Passenger side exhaust manifold gasket- have to remove for oil filter housing
New front and rear main seals
New Vave Cover Gaskets
All new radiator/coolant hoses (all 10 of them)- mine were original except for 2 hoses going to the radiator
New heater valve- original broke when removing old coolant hoses. The plastic was really brittle. Good thing it broke now and not down the road
New plastic Exhaust sensor- broke when pulling the valve covers off. Dunno what this sensor does.
New fuel filter - fuel pressure lines were depressurization and I had it in the garage waiting to be done
Did a 90% job of degreasing and cleaning the block, valley of the engine, and intake manifold. I didn't spend a ton of time here. Just got the easy quick stuff since I know it will be dirty again with time and this isn't a show truck.
All new coolant
Retaped up some of the wiring harness with electrical tape as it was unraveling due to age.

-Scott

 

[firefly1246]

Here are some photos, more photos check out the Flickr page.

Broken Rear Timing Chain Guide/Tensioners. These two pieces should be connected.

Front Center Timing Chain Guide: The item circled in blue is the spring tensioner that broke, it slide behind the post (circled in green). This item should be up where the metal piece is circled in red. The chain would rattle against the metal circled in red at startup.

Wear on the spring tensioner after it broke, note this is only from ~10 miles of driving after it broke.

Bottom half of the broken spring tensioner;

Clean inside of a 245K motor:

 

[Cheeezzy]

Mine doesnt rattle when cold purrs like a kitten until it gets warm then i hear a rattle.Only when idle you cant hear anything while giving it gas it goes away.Im so confused.

 

[firefly1246]

Mine doesnt rattle when cold purrs like a kitten until it gets warm then i hear a rattle.Only when idle you cant hear anything while giving it gas it goes away.Im so confused.

Where in the engine does the rattle sound come from? Back passenger side is timing chain. Front driver side is a timing chain.

To try and isolate it. You can remove the serpentine belt and try and listen for the noise. If the noise goes away with the belt off it is one of your accessories. If you still have noise then inside the engine.

-Scott

 

[scapino]

Mine doesnt rattle when cold purrs like a kitten until it gets warm then i hear a rattle.Only when idle you cant hear anything while giving it gas it goes away.Im so confused.

I'm in a similar boat. My '05 S/T has 205k miles and it purrs just fine (800 RPMs) when cold. However, after it warms up it rattles & vibrates; but only when in Drive or Reverse AND while stopped (at a stop light). If I put it into Neutral or Park the rattle goes away; back in Drive and rattles again. It's getting to the point that at every stop light I switch to Neutral coz the rattle is so annoying. It seems that once I drive off the rattle stops - or at least I'm not noticing it because of road noise.

I really don't think this is related to the Timing Chain or Cassettes so i'm sorry for being off topic - it's just that Cheeezzy's problem seems similar to mine. Any thoughts?

 

[CDW6212R]

I'm in a similar boat. My '05 S/T has 205k miles and it purrs just fine (800 RPMs) when cold. However, after it warms up it rattles & vibrates; but only when in Drive or Reverse AND while stopped (at a stop light). If I put it into Neutral or Park the rattle goes away; back in Drive and rattles again. It's getting to the point that at every stop light I switch to Neutral coz the rattle is so annoying. It seems that once I drive off the rattle stops - or at least I'm not noticing it because of road noise.

I really don't think this is related to the Timing Chain or Cassettes so i'm sorry for being off topic - it's just that Cheeezzy's problem seems similar to mine. Any thoughts?

You better start planning for valvetrain work on that SOHC.

Ignoring it is way more expensive than fixing it now.

This applies to all owners of the 4.0 SOHC Ford engine.

 

[koda2000]

Are you sure your noise isn't from a broken heat shield on your exhaust system? From your description it doesn't sound like it's timing chain related. I had this happen on my daughter's '00 Mountaineer and it it turned out to be a broken weld on a heat shield. It would only make noise and vibrate at a certain RPM. I fixed it with a radiator hose clamp.

 

[scapino]

Are you sure your noise isn't from a broken heat shield on your exhaust system? From your description it doesn't sound like it's timing chain related. I had this happen on my daughter's '00 Mountaineer and it it turned out to be a broken weld on a heat shield. It would only make noise and vibrate at a certain RPM. I fixed it with a radiator hose clamp.

Well... yes i had the same problem with the heat shield. And yes, a $3 dollar hose clamp from Amazon fixed it perfectly.

I honestly don't think the rattle (its more like a vibration) is related to the timing chain. But I'm not sure how to troubleshoot this by myself? I mean I could put a brick in front of the tire; place it in Drive; and then pop the hood to start looking around. But i'm pretty sure i'll end up squished between the truck and garage wall...

Anyway, like i said I only notice the rattle/vibration when stopped (stop light or stop sign; ect). And it does seem worse after it warms up. Putting it into Park or Neutral and the vibration goes away.

 

[ExplorerRider]

The two external tensioners are the ones people know most about. Those have springs inside which is the part that wears out. The oil pressure is a supplement, so they work fine until the spring inside gets weak. That can happen early like you read of a 40k motor dying, or 100-150k for some lucky people. It's a simple spring, and over time it will get weak, so a maintenance schedule like 75k is wise. I'm at 148k now, and did mine when I bought it at 77,450 miles.

There is also a front tensioner that has thin bent steel pieces that add pressure to the main jack shaft chain, plus another chain guide near it. Those two parts also get worn over time, and then that main chain becomes loose, but that's usually well after the timing chain parts have issues.

4WD's also have an extra tensioner on that tiny balance shaft chain. It's cute(the chain).

Sheesh! I bought a 4×4 Explorer w/4.0V6 back in '18, 145,000ish. But IDK that the tensioners have ever been replaced, & so how many tensioners am I looking at buying altogether?

 

[CDW6212R]

Sheesh! I bought a 4×4 Explorer w/4.0V6 back in '18, 145,000ish. But IDK that the tensioners have ever been replaced, & so how many tensioners am I looking at buying altogether?

Two external tensioners, do those now and every 100k more or less. Buy OEM for those, not the aftermarket. They are not expensive, maybe $100 total, they used to be under $60. Those are usually the first to weaken, and then the chains run too slack, causing faster wear of the internal chain guides(plastic). If you keep up with the external tensioners, change them regularly, then the internal may last a normal lifetime. Also note that many have changed those external tensioners with manual aftermarket types, made for ATV's, with very good success.

 

[ExplorerRider]

Other's here have said to replace them at 75K. You need to be aware that if your guides are already broken, removing the old tensioners can cause things to fall apart. The tensioners are a bad design, but the guides and cassettes are what eventually do you in.

Yeah... The more I read into changing the two external tensioners on my 4.0L V6 '05 Explorer w/156,000 on it, the more hesitant I become! I bought it from Bening Mazda here in my town, & I believe it to be a one-owner soccer mom's car as it still had the manual in it, it still runs well, is relatively quiet for 150,000+, I'm nearly certain it came from Bening Ford an hr up the highway, & all I could find was an alternator stamped "remanufactured by Ford Mo. Co" on it & an aftermarket "rear tie rod end." Would I probably be wiser to just keep the Motorcraft filters & full synthetic Valvoline in it every 4,500 miles???

 

[410Fortune]

I’m would change the tensioners with ford parts only (or research manual tensioners)ford recommends timing chain tensioners for the 4.0 sohc engine at 90k miles

Change the oil w full synthetic of your choose ever 3500-4500 miles. Extremely important w a sohc

Where do you get ford tensioners for $50 each?

The manual tensioners are made for the Polaris northstar 1000 engine (999cc dohc) found in Utvs
Research is key to deciding if you want manual tensioners
Pioneered right here on this forum by yours truly

 

[ExplorerRider]

I’m would change the tensioners with ford parts only (or research manual tensioners)ford recommends timing chain tensioners for the 4.0 sohc engine at 90k miles

Change the oil w full synthetic of your choose ever 3500-4500 miles. Extremely important w a sohc

Where do you get ford tensioners for $50 each?

The manual tensioners are made for the Polaris northstar 1000 engine (999cc dohc) found in Utvs
Research is key to deciding if you want manual tensioners
Pioneered right here on this forum by yours truly

No, I'd totally be open to the manual tensioners, (BTW, your idea reached the 4.0L SOHC Rangers forum) but I think I'm just gonna grab a set of Ford Genuine Parts tensioners as the manuals would be abv my pay grade. Fingers crossed, knock on , Good Lord willin' & the creek don't rise! But I certainly do thank ya!

 

[410Fortune]

Ford hydraulic tensioners are $$$$
(If they are $50 online then they are not actual motorcraft parts)

Manual tensioners are extremely cheap

Our ideas always make it to ranger forums
That is why explorerforum is the absolute best

I love your post
My creek is rising we have had some warm weather and snow is melting I am under flood watch… my property floods every spring. It’s how high the water comes, we have normal “watering the grass” flooding and then we have holy crap I have 14” of water in my garage”
Flooding. One is fun the other sucks very very much

 

[ExplorerRider]

I’m would change the tensioners with ford parts only (or research manual tensioners)ford recommends timing chain tensioners for the 4.0 sohc engine at 90k miles

Change the oil w full synthetic of your choose ever 3500-4500 miles. Extremely important w a sohc

Where do you get ford tensioners for $50 each?

The manual tensioners are made for the Polaris northstar 1000 engine (999cc dohc) found in Utvs
Research is key to deciding if you want manual tensioners
Pioneered right here on this forum by yours truly

Also, I only found a set of Ford tensioners for $120 & another for $165, respectively. $50 weren't my numbers. But ya know what? Tell me more abt these manual tensioners... Can't hurt!

 

[Fordtruckfan89]

I just bought a set of OEM ford 4.0 tensioners off eBay. Don't come with washers, gotta get them separately. I do have some manual ones, but still kinda cautious on them, no offense 410fortune.