How many miles on the timing chains typically 4.0L

[2000StreetRod]

possibly accessories

Does this sound familar to timing chain failure?? . . .

I never can tell much from internet videos but to me it doesn't sound that much like timing chain rattle. It could be from the A/C compressor, water pump, power steering pump, alternator, serpentine belt tensioner or idler. To eliminate those sources you can remove the serpentine belt and run the engine for 30 seconds. If the sound stops then it is associated with one of the accessories.

 

[Exproblems]

Doesn't surprise me, once the sprocket lets go, its a new head, you cant do 1 head without the other, so thats 2 heads, once you do that, and the new timing gear, then you may as well put in a reman with a 12 month warranty.

And thats what a mechanic / business will always do, as then he doesnt have any risk of the comebacks.

Yeah, both mechanics said it was cheaper to replace the motor than take the old one out and tear it apart looking for other damage and broken pieces, most likely being bent valves and head damage. The Ford guy said a new head cost $1,000 alone, so that would be $2k just for the heads at dealership prices. The Ford reman motor I have came with a 3 year, unlimited mileage, parts and labor warranty.

 

[2000StreetRod]

why both heads?

Doesn't surprise me, once the sprocket lets go, its a new head, you cant do 1 head without the other, so thats 2 heads, . . .

Why is it necessary to replace both heads when only one is damaged?

 

[rmcknight]

new valves / valve grind on only one side and not the other, can cause run issues and exhaust issues, higher compression and increased power out of that side etc. v6 engines are already very hard to stop shaking hence the attempt with the balance shaft.

 

[LubeMan1]

I never can tell much from internet videos but to me it doesn't sound that much like timing chain rattle. It could be from the A/C compressor, water pump, power steering pump, alternator, serpentine belt tensioner or idler. To eliminate those sources you can remove the serpentine belt and run the engine for 30 seconds. If the sound stops then it is associated with one of the accessories.

Good idea...I'll try that later if possible, I have a feeling it might be exhaust gasket, But I also had a used tranny installed about 1000 miles ago could something in there be causing that noise?

 

[2000StreetRod]

flexible hose

I've used a length of flexible hose in the past to find exhaust leaks.

 

[LubeMan1]

Really??? It should seem obvious but how exactly do you do that? Just stuff it near the manifold and listen or feel for actual exhaust coming from the hose?

 

[2000StreetRod]

using a flexible hose

It's merely a matter of placing one end at your ear and placing the other end at suspect connections. For exhaust leaks it works better than my mechanic's stethoscope.

 

[Extremistno9]

our 2003 4.0l had 133k on it when we bought it and was smooth and quiet. At around 170k it started to make some chain noise. It got progressively worse until at 189k it sounded so bad it was frightening to drive. We're talking chain noise so bad it sounded as if the whole vehicle was about to fall apart.

Changed all the chains, guides, etc at 190k.

How much did all of that cost? My '02 with 149K miles started acting up a little less than a year ago, month or two after I drove it off the used car lot. Trying to decide if I should fix it, wait to see how long I can go, or prepare myself for a new car.

 

[RKelly2233]

Bought my 03 in 06 with 60K on it. I started hearing a little rattle here and there around 150k. I still hear it a little more often depending on the conditions around (whether its been running or cold or its hot or cold out). I now have 212K miles on the orig chains. I plan on buying another Aviator soon but still plan on driving this till the chains go out. I don't abuse her- rarely go over 3K rpms at any time... Regular oil changes on time. I keep my rpms around 2k even during acceleration, its a little slow but I get around 19mpg closer to 20 most of the time. Im also on my orig tranny as well with flushes at 75k, 100k, 153K and 207K. Don't abuse your can and it'll last!

 

[Mike-in-Maine]

How much did all of that cost? My '02 with 149K miles started acting up a little less than a year ago, month or two after I drove it off the used car lot. Trying to decide if I should fix it, wait to see how long I can go, or prepare myself for a new car.

I figure i'm into it for about $800 total. I did all the work. It was the whole job, front and rear chains; pulled the engine. Had to clean out the plastic bits from the block, so that total $ amount included upper and lower pan gaskets, all chain tensioners including counterbalance tensioner, timing chains, sprockets, front gaskets, rear plug, new spark plugs and wires, new coolant sensor and t-stat housing w/ gasket. Probably a few other odds n ends I cant think of. It wasn't a hard job at all, but just took a lot of time, (working day job with busy weekends and evenings)

Also bought the timing tool set... that was about $230.

 

[Extremistno9]

I know this is a tough question to answer, but I am curious to opinions.

Rkelly, you got about 62K miles since you noticed the issue. Others seem to have put on a good amount of miles before replacing as well. I am thinking of taking a 2000 mile round trip this winter with the explorer (with wife and two young kids). Day in and day out, seems ok to drive but nervous about a long haul like this. I did take it on a 5hr trip this past summer and things were fine.

What are your thoughts?

Thanks!!

 

[2000StreetRod]

noise source?

Extremistno9, have you located the source of your noise? If you have 4WD then you could be hearing the balance shaft chain. Pieces of the tensioner and guide usually end up in the oil pan or get trapped in the oil pickup screen. If the chain breaks but doesn't get caught in the crankshaft to jackshaft chain then it's no big deal.

Many members have driven tens of thousands of miles with a failed crankshaft to jackshaft chain tensioner. If the chain breaks the valves will probably get bent but the chain rarely breaks.

If the left or right guide assembly is broken the associated chain will eventually slip or break. If the slip is small compression will be reduced. If the slip is large or the chain breaks valves will probably get bent. Sometimes the chains will get so loose that they eat thru the valve covers so oil is lost.

If you're going to take a trip with your family in the winter with chain rattle your auto insurance should have roadside assistance coverage and you should have emergency supplies (blankets, water, etc.) in case you get stranded.

 

[Extremistno9]

I am going to spend some time this weekend trying to determine that. Thanks for the advise; may be a good time to sign up for AAA. Paying $3000 for the dealer to fix it is not an option and neither would it be for myself to pull the engine as I do not have this type of car repair experience. See what this weekend digs up.

 

[dbailey]

Just put a new long block in my 03 Sport trac that had 265,000 on it and it was replaced due to a broken valve spring not the chains.

 

[Extremistno9]

I did some quick testing this morning. I started up the engine and revved it multiple times holding it at various RMPs while under the hood. I did not hear any rattling that I hear when I normally drive the car. The engine was fairly warm though from a previous drive this morning (15 deg C outside though). I will try it again cold if I can. I do have the noisy cold start-up though as others have described.

This leads me to what somebody mentioned earlier is that it could be a heat shield. I checked the heat sheilds that I could see and they all seem solid and in place. I will do some more digging to see what else could be making the noise.

 

[Extremistno9]

...or the harmonic balancer in the transmission? I saw a video from HiImBrian and just hearing him move that pc across the drive shaft very closely sounds like what I am exeriencing. So do I pull that cover off and cut the thing off as HiImBrian did, assuming this is the issue?

 

[espeed]

Just for clarification for anyone not familiar with the 4.0l motors..

The above post from rmcknight is about the 4.0 SOHC motors..

The older 4.0 OHV motors from earlier generations didn't have to worry about timing chains...


And for just another anecdote of info.. our 2006 4.0 sohc has just over 230k miles on it.. Motor is still quiet.

~Mark

I have a 2000 Ford explorer 4.0 sohc. I don't hear any noise out of it. The motor has 360,000 mi on it and runs very strong. I often worry about the timing chain or chains going bad, but I haven't heard any noise?

 

[410Fortune]

You would hear more use at cold start sounds like a rattling, last for only a couple of seconds

This would be the hydraulic chain tensioners slack for a few seconds but then pump up with oil pressure

If you change your oil every 3000
Miles and use the correct stuff these engines can go for a very very long time

Ford recommended changing chain tensioners at 90k miles just fyi lol lol