This depends on whether or not your engine is classified as 'interference' or 'non interference'. If it's non-interference and the chain breaks, it just stops running....in the best case scenario. If you water pump is driven from that chain, sometimes the breaking chain can rip out the pump.

If you find out your engine is interference, it may be prudent to at least inspect it for tension, or just replace it since you're already in there. Just replace the guides and the pump too, if applicable.

 

Duras are interference. Chain might live but the cheap guides or a tensioner can go and then ur down to 0hp. R

 

There is a chain tensioner to take up the slack. I'd just run it, but if you want you could pull the cam cover off & have a peek at part of your chain. I'd just make sure your doing all the mainence your doing. btw the oil pump is chain driven & not the water pump.

 

Ok, so what I'm understanding here is that since my Duratec is "interference" then if something goes wrong enough to stop the chain from working, the engine should shut down preventing internal damage.

So there is no actual mileage point to replace the chain but it should be inspected on a higher mileage (175kish I'm assuming) engine?

Are the guides and tensioner more likley to go bad than the chain itself? What would it sound like if the chain was "slapping" not properly tensioned?
It makes no unussual noises right now, but if something does happen I guess I'll know where to look.

 

Interference= say if the chain snaps then the pistons coming up hits the open valves. It happens so fast. You'll have more problems w/ a timing belt then a chain driven cams. You hear or read alot about replacing belts vs chains. Yea, the guides & tensioner would go before a chain. I've seen many 46's w/ over 300,000 miles on the oem chain, guides & tensioners.

 

Please read some engine manuals and no more forum board reading. Educate urself because your posts show that you should not be taking any portion of your engine apart. Call in some expert help you learn it or get bent over by a shop doin it. Much more to get wrong than with a non interference engine and u need the skillset for this job. R

 

Unless the chain stretches enough that the tensioners can no longer take up the slack and the chains start slapping around, it is fine.

I wouldn't take apart a 170k me motor to replace a timing chain that is simply high mileage, I would save the cash for a complete engine replacement.

 

I had over 240K on Orangell0! Semi-T-bone killed him not the timing chain!

 

So far I've seen a few that took out rod bearings, but yet to see a timing chain as the first thing to go.

 

& those are from ppl that let their oil get low.

 

Only way to check your chain is to pull it out and measure "stretch" the chain wears inside the rivets. taking off the valve cover and "taking a peek at it" inst going to tell you jack shit..... What does the Ford manual state for service interval?

Timing chains last longer than belts but you still need to check them. the typical faults that i have seen on chains is the auto tensioner tends to stick or not take up enough slack....one of my first mods on every motorcycle engine is to get rid of the factory chain tensioner and change it out for a manual adjuster.

 

i too would suspect the chain tensioner or guides to go before the chain itself. Ive seen duratecs with 300k on the original set so who knows how long yours will last

If it does ever let go, low mileage 2.5L engines are flooding salvage yards now [deviltail]

 

My chain had stretched enough at 175k miles to throw a constant 'camshaft position sensor' code. After a few OEM sensors, I checked the timing.

Almost a full tooth off retarded from stretch. I didn't have the means at the time for new chain and components, I loosened the cams, put the engine back in time and no more code. Haven't had it come back, but being that the chain is stretched, I suspect I'm losing performance and will see the code again soon until I can replace the chain. 10k miles since that and it's still 'fine'.

I'd get a timing kit and see if it's perfectly in time. If it is, no worries, if not. Look into replacement.

 

I'm at 212K on my D23 and am debating just biting the bullet and doing a timing chain replace. I DON'T want to have a catastrophic engine failure.

I haven't researched how big a job this is but i assume it doesn't involve removing the engine, but just a wheel and fender liner to access the cover.

 

No engine removal required, fairly easy to get to. When I installed a pr of cams, forgot about the tensioner & had to remove the timing cover, a couple additional hrs.

 

Lol silly kitty.

Motor Mount maybe. I forget what dtex look like. [sadpanda]...

 

Coming from the Saturn world (timing chain as well) there are people running the stock chain for 400K+ miles. As mentioned, keeping oil level up and a reasonable OCI with quality oil prolongs the life of the chain. If you want to waste money, replace the chain, but it will a make ton of noise before actually breaking. Timing belts actually stretch less and keep engine time more precisely than a chain ever will; I know an old racer that refuses to use a chain on the BBF engines they ran in the race car for this very reason.

Just keep good oil up to the full mark and change it on a regular basis and the timing chain should last the life of the car.

 

and coming from the VW world if you have a VR6, your chain guides start going to chit at 100k and are on the trans side of the motor. oooooh what a fun job that is!. you want to see some funky looking valves look up VR6 bent valves.

 

I replaced my timing chain at ~150,000 miles while doing a cam install. everything was in really good shape, and I wouldn't have replaced any of it if I weren't doing the cams. The only obvious wear was a VERY small lip on the surface of the guide/tensioner surface, but there was lots of material left before it would have been a metal on metal situation.

 

I just changed mine at 270000km

 

I am also thinking about this chain/tensioner preventive replacement. I'd say lubrication is a crucial factor. As I have always run on synthetic oil, changing it every 5k miles, after reading this thread I think mine is one of those who run past 300k without worrying about it.

 

FWIW, I have 378,000 km (235,000 miles) on mine, and I *think* I *may* be hearing a tiny bit of timing chain noise. It's not enough to cause me to worry yet. If it gets worse, then I'll start thinking about either doing the job myself or shipping it out to a mechanic.

Honestly, I wouldn't even think about the timing chain until you're pushing 250,000 miles/400,000 kilometers.

 

This^^^^^^^^^& those are some miles.

 

I'm about to hit 180,000 miles on the original timing chain in my focus.

 

As mentioned in the post higher up the tensioners and slipper guides go way before the chain does almost always. They break first and then chain lets go in short order.

 

Non interference engine if 2 liter

 

That's only true for the Zetec and SPI. The SVT, Duratec, TiVCT, and EcoBoosts are interference motors.