hello. I have tried searching for what I am looking for with no results. it keeps saying no match found. so here is my question. How hard is it to just replace the tensioners and guides? I know its good to go ahead and replace the phasers and chains, but im not going to. the issue right now is the tensioners and guides. im not worried about tearing everything down to the timing chain cover and removing the cover. what worries me is removing the tensioners and guides. I understand these are interference motors and any slight thing wrong can cause catastrophic failure. but if my research is correct I do not have to remove the chains in order to replace the tensioners and guides correct? and since I don't have to move the phasers, or remove the chains, the timing should not be interrupted right? I should be able to remove and replace one tensioner and one guide at a time and bolt everything back up without having to do anything else and worry about the timing right? any help will be greatly appreciated and I thank everyone for there time ahead of time.

 

I'd be interested in knowing this too. Theoretically sounds correct, but I'd like the feedback of some tenured gearheads.

 

You should have no problem doing that. Just put the keyway on the crank at the 12 o'clock position. Remove the tensioner and guide. Reinstall with the new components.

I just replaced all the timing stuff on mine, and don't see an issue with only replacing those parts. If you do not remove the chains, and keep up the slack so you don't slip a tooth you won't have issues with the timing.

 

To add to what baticus said, I use a zip-tie on the chain near the crank to take up the slack. If a tooth doesn't fall off, the motor will be in time. But just in case, set the crank key at the 11:00 position and the cams should be at roughly 10:00 and 12:00. If they're 180° off, turn the crank clockwise once more to the 12:00 position. If the a tensioner arm has worn into the metal, you need to replace the chains too. Replacement chains have colored links to make installation easy. If it were me, I'd replace them regardless while you're in there, but it's not required if there was no metal to metal contact.

That's the easy part. Here's the more important question... Why are you replacing them? If the guides have worn or broken, you absolutely must remove the oil pan and clean or replace the pickup tube. I've seen this more than once. If you skip this crucial step, your engine won't be running for long.

If the tensioner is causing a brief noise at startup, no big deal as long as the guides are intact and not worn to the metal. If the tensioner isn't holding the chains properly with the engine running, look for an oil pressure issue in the head. The rear cam bearing girdle has a small orifice and if it clogs, you lose oil pressure to the tensioners.

This isn't a common issue necessarily, but it happens. I've seen this failure first-hand on three modular engines, and the root cause on every one was lack of maintenance. Engine sludge starving the head of oil is where the downward spiral began. The owner driving the car after noticing a timing chain noise killed it. And one where the owner tried cleaning the pickup tube and replacing one spun rod bearing after the failure was just beating a dead horse.

Hard lessons to learn, but this information may help you out. If your truck is 2WD, the oil pan shouldn't be hard to get off. Either way the timing cover isn't bad. The power steering pump is probably the hardest part to get off. Unless you have or rent the pully remover and installer. Then it's pretty easy stuff. These motors are awesome since you don't have to drain any coolant to do this job.

 

because I have a start up rattle that last a few seconds then goes away when it builds oil pressure. if the old guides are broken I will drop the oil pan and clean out the oil pickup

 

The Zip tie works good. What brand oil filter are you using? If you have a start up rattle it is possible with some oil filters to drain back making it necessary for the filter to refill before building oil pressure. This can allow lash adjusters etc. to make noise for a few seconds on start up. Motorcraft oil filters are recommended for this reason.

 

That's the perfect approach. You won't know what's going on until you take the timing cover off. Plan on replacing the tensioners and guides at a minimum no matter what you find. If a guide isn't broken or worn yet, the timing chain slapping around causes fatigue.

If you want to go deeper while you're already there, you may consider replacing the cam phasers if they the original ones. They are known to fail and you'll have the luxury of full access with the timing and valve covers already off.

Regarding oil filter selection, I don't disagree with the recommendation as the Motorcraft filter is the best bang for the buck. But I'll add this. The timing chain tensioners are spring-loaded and designed to provide adequate tension at startup. This is why even when you change your oil and filter, there should be no noise when starting the engine.

These engines are overall the most user-friendly to do timing chains on in my experience. If you want to see what a timing chain nightmare is like, look up the 4.0L SOHC V6 in the Rangers, Exporers, and Mustangs. The moment you hear a timing chain noise, it's usually too late. And there's 3-4 chains on those engines (some have a balance shaft). The kicker is that the one that fails 95% of the time is the right side, which is on the rear of the engine. You have to pull the engine to change it, and it's a huge pain in the ***.

 

its been rattling for about a year. but I use 5w20 amsoil and filter.. better than motorcraft




the previous owner put cam phaser limiters in it before he sold it to me. I shouldn't have no more issues with the phasers..

 

Well hell. That's all the justification I need to change the phasers and have the PCM flashed at the dealer. But that's me.

 

well guys I got about two hours in to the job. I got everything off except the timing cover. so tomorrow all I have to do is remove the timing cover bolts and replace the tensioners and guides and button her back up..

 

What you say regarding the 4.6/ 5.4 chain tensioners is partly true, they can still make noise even with the spring tension which is not 100% supportive or reliable. However at this point I don't see where anyone is positive it is the tensioners that are making the noise. I would investigate the possibility that the lash adjusters are making the noise because of a cheap oil filter before pulling the entire front cover. It may turn out to be tensioners but changing a oil filter trumps changing the front cover especially since I believe this is on start up only? JMO

 

I guess I'm running off the assumption that only Harry the homeowner uses the garbage filters. If oil does drain back on a regular basis, it could cause accelerated wear on the engine. However once the noise starts, there's a mechanical issue that needs to be corrected.

But again, I agree 100% that an inferior oil filter can bite you in the *** over time. There's a lot of good options (and opinions) out there. Motorcraft is by far the best bang for the buck. NAPA/Wix Gold is a step up, and the hardcore oil nut can go nuts on a Mobil1 or K&N filter. Plenty of other good options out there. I personally default to Motorcraft unless there's a special going on like buy a jug of Mobil1 EP and get a free Mobil1 filter.

**Note: This is what I do. Fellow F-150 owners, please don't start another oil war. I only speak in terms of overall 'bang for the buck', short and long-term.

At the same time, I'm sure that plenty of people consider this an acceptable condition. If I heard the slightest timing noise on startup, I'd brush it off as a fluke. But if it happens twice, I'm removing the cover to repair the issue before it can turn ugly. Every time an engine is started with timing chain slap, that's the sound of the timing chains beating the sh*t out of everything they touch. Fortunately I have never experienced this on any modular Ford engine that I have owned or family vehicles I was responsible for maintaining. But I've worked on a few that did. Problem is that by the time it was brought to me, the engine was shot. Three of them so far. Two of which were extremely cruddy due to improper maintenance. The third was a broken guide that the owner decided to drive on for months until the engine seized from a clogged oil pickup tube.

These are outstanding engines. But like any other, proper care is key. I should find a pic I have of the last one I worked on and post it.

 

well anyway I wasn't worried about it being an oil/filter problem because I use amsoil oil and filter. 5w20.. but that was the problem. both guides were broke and both tensioners had blown gaskets.. no more rattle. thanks everyone

 

Glad you got it back together. Anything in the oil pan?

I almost forgot. Just for reference if other people land here, this is what happens when you don't change your oil as recommended. It was the last 4.6L I did that failed due to poor maintenance. Oil passages starve the head for oil tensioner doesn't apply adequate tension, timing guides self-destruct, oil pickup clogs, and then you just ruined an engine that would've lasted 300,000+ miles. If I recall correctly, almost half of the lash adjusters were destroyed and one of the rocker arms said "oh f*ck this" and shot out.

 

I have seen many engines with this condition that came in from dealership pulls. We did a study on this to determine the root cause. While some were personal vehicles the vast majority of engines like this came from fleet vehicles. Police, taxie, delivery companies etc. What we discovered after much research was that most of these companies were using inexpensive bulk oil. They purchased the cheapest oil they could find in bulk. Letters were sent to all fleet services informing them that the warranties would be void if SAE certified lubricants were not used. On a somewhat different note we had I believe 7 failed engines come in from one particular police dept in Arizona, they were allowing some of the prisoners to change the oil and maintain the police cars...and they weren't changing the oil I guess they figured it was payback time... We were informed that that dept changed its policy.

EsJayEs, Did this engine happen to come from a commercial fleet vehicle? Were the cyl head oil drain back passages pretty well blocked? Was the original factory oil filter still on it? There is a code on the original filters that have hung a lot of people and canceled their warranty.