Good morning all.

I have an 02 5.4 with 105,000 ish miles.

Last week I started to hear what I thought was a belt idler pulley going bad. I replaced the lone pulley and the noise persisted. I replaced the pulley on the belt tensioner and the noise remains.

Today, I removed the belt and started the motor, and the noise is still there. So, I am thinking it may be something with the timing chains.

Does anyone have first hand knowledge of this issue?

Any do's or don'ts that I should know about?

Thank you in advance.

 

105k isnt that that many miles for these engines. the chains are not usually a issue as long as u keep up with oil changes etc... maybye its a noise valve or lifter??

 

POSITIVE THINKING.....I like that!

But the noise is definately up front.

I am told that the chain tensioners are controlled by oil pressure. So, there is a chance that they are clogged or worse, that I have an oil pressure problem.

I just changed the oil two weeks ago, so I am running a quart of 'engine flush' and changing the oil just in case.

Thank you for your input!

 

STOP!! NO ENGINE FLUSH LOL. add half a quart of tranny fluid to your oil drive around for like 20 miles,drain that and do a regular oil and filter change. that might free up any sticky lifters or valve. tranny fluid is a good detergent. engine flush stuff causes more problems than it solves, just my two cents.

 

What exactly does this noise sound like?

 

The noise...well...it sounds like a timing chain rubbing on the aluminum case.

Here goes (what you REALLY wanted to see), the noise is a rythmic Shhhhk, shhhhk, shhhhk. The noise changes with engine RPM.

Since I changed the oil and filter (from Mobile1 to Ford syn/blend) the noise is still present, BUT....If I goose/rev the motor, the noise will go away for 15-20 seconds.

The noise is still present when the fan belt has been removed, so it is not an accessory. It is definately coming from the front of the motor and the timing chains tensioners are controlled by oil pressure. That does not bode well.

Anyone know if a 429 will bolt up to my automatic transmission??? I have a fresh big block ready to go!

 

have u tryed a piece of rubber hose as a "stethescope" put it against the timing cover and your ear, check around that way.

 

doesn't FoMoCo recomend changing the timing chains at 100,000 miles anyway???

 

they do?

 

Try replacing the PCV valve. I know, sounds strange, just give it a shot.

 

Um, no.

 

I worked on a friend's Mustang GT a while back, about a year ago, it was a 2001 Mustang with the 4.6 of course.

It was making a "SMACK....SMACK....SMACK....SMACK....SMACK.... " sound that was obviously coming from just behind the timing cover on the passenger side. It was a bad chain. And while oil does flow through the tensioner to lubricate the chain, the tensioner is actually spring loaded. When you install it, you compress the spring in the tensioner, insert a paperclip in the whole to keep it compressed, install it, pull the paperclip, and that's it. I also replaced the tensioners, guides, and chains on both sides "just in case".

If you have that many miles on it, you don't want to flush it now, knocking all that crap loose could cause a lot worse problems than some chain slap.

 

A bad chain? I can believe that!

So, I am going to guess that it stretched? Do you recall the approximate costs involved?

So, I should look at replacing the chain guides a chains (since I am down there). Did you replace the timing chain gears too?

do you have any pointers other than what I have found in the Chiltons book?

 

These chains don't stretch. Period. On a properly maintained engine, the chains/gears/guides will easily outlast the rest of the engine.

Only time you'd really see/hear noise in the timing assembly of a modular engine is from lack of maintenance. Sludge blocks the oil passages going to the timing chain tensioners, allowing the chain to flop around against the guides. Occasionally, the gasket between the block and tensioner blows out, reducing the amount of oil available to the tensioner causing the same concern. The tensioner isn't exactly "spring loaded," it's tensioned against the guides with oil pressure.

I suggested replacing the PCV valve because the spring inside the valve can break; plastic transmits noise very well, and the little pintle in the valve rattling around with a broke spring sounds like something in the valve train or front of the engine is coming apart.

Always start with the least intrusive, simple things first before anything else; it'd be a bitch if you had the chains/guides/tensioners replaced, only to find out it was a $7 PCV valve rattling, wouldn't it?

 

I agree.....Look at the simple things first!!!

The PCV valve was replaced last month. IT was malfunctioning.

I have owned this truck since new. It has had it's oil changed roughly every 3k miles (by me using mobile 1). My driving is 99% highway and light towing (mustang and firewood). The truck has been maintained and not abused.

Timing chains do stretch. I remember my 68 camaro's chain stretching soo much that it wore a hole in the timing chain cover. Therfore...I can believe the chains stretched and/or the chain guides have become severly worn.

There could also be a problem with the chain tensioner. Whether it is an oil gasket or it just plain failed, the noise is coming from the passenger side timing cover without question. Even with the belt off, the noise remains and is localized to just behind the belt tensioner. the drivers side is currently quiet.

I have heard that if the chain guide is severly worn, I should consider dropping the oil pan to look for/remove any plastic fragments from the guides.

Now I just need to find something to take to work!!!