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I bought my car used, and unfortunately I have no idea when the timing belt was last changed. I decided to open the timing belt cover today to take a look. The top of the belt seemed a bit shiny but I'm not really sure what's considered normal or not.

Here are photos I took of the belt, any opinions would be very appreciated.

enter image description here enter image description here enter image description here enter image description here

http://imgur.com/a/gkabQ

Thanks

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    How many miles are on the car right now? – Pᴀᴜʟsᴛᴇʀ2♦ Aug 17 '16 at 0:04
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    If in doubt, change it. Timing belts are a lot cheaper than engines. What car is it? – PeteCon Aug 17 '16 at 2:27
  • What car is it?? Make, model, year, engine size... this information may directly affect the urgency of replacement. – SteveRacer Aug 18 '16 at 1:21
  • The belt looks fine, but the installation was poor. That belt should be in the middle of the gear, not the inside edge. Look for other installation issues, such as overtighting of bolts or damage to the front engine mount. Truth is, seeing how that appears to be a shade-tree job, if the motor has less than ~120 KM on it I'd probably not touch it as you might be in for a world of hurt if a bolt was overtightened and breaks off in the block, and the belt replacement likely happened at 90K-100K. – dotancohen Aug 18 '16 at 12:20
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Unfortunately there is no magic eight ball which can tell you how many miles are on a timing belt. This is my own opinion, but I'm sure it's shared by most:

If you don't know the mileage of a timing belt on a car with an interference motor, change it. You can never go wrong.

The one you are showing in the picture looks like it's been around the block once or twice. I'd sure as heck change it.

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  • Thanks for the reply. I'm aware that there's only so much information you can glean from the photos, in reality I'm just looking for a general reaction from experienced users. Ranging from "it's fine", to "wow change that asap"--from my novice view, it appears to be a little rough but not in any imminent or obvious danger of snapping. I definitely want to change it when I can. – Jay Aug 16 '16 at 23:51
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    Really, though, if you don't know the mileage, it's a ticking time bomb just waiting to happen. Once changed, you'll know and can go from there. No sense lunching a relatively good engine on a guess. Just change it ... you cannot go wrong. A couple hundred now or a couple thousand when it breaks. Your choice, really. – Pᴀᴜʟsᴛᴇʀ2♦ Aug 16 '16 at 23:53
  • I'm with Paulster. If you have no clue how many miles is on the motor, change every wear item you can if you have the chance. Especially sensitive things such as the timing belt/chain which can cause catastrophic engine failure. – Jeep Cherokee Rescue Society Aug 17 '16 at 12:03
  • Once additional note, when you do change it, write the date and mileage in some kind of permanent may into the timing belt cover. – Steve Matthews Aug 18 '16 at 15:22
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    @Mauro - In the last image there appears to be some belt residue on the engine, just to the side of the pulley ... something else to consider. It all adds up to needing it replaced in my head. – Pᴀᴜʟsᴛᴇʀ2♦ Aug 18 '16 at 23:27
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The belt looks okay, but @dlu is totally correct I'm not liking the track. The first photo it almost looks like it's rubbing on the inside of the cam flange.

In any case, you can count the cracks on the belt teeth. If you bend the belt away from the teeth and see more that 3-5 cracks over a 1" span, the belt needs to be replaced.

Get a Conti or Gates kit that includes the waterpump as well. Money well spent. You can save money by ordering online... I don't think this is emergency crisis mode, but as other posters mentioned the only timing belt you really know is the one you're installing right now.

This job is a really rewarding one for a DIY and not too complicated, as long as you take your time and mark everything carefully. I use those paint pens in bright flourescent colors along with a pair of 2.50x drugstore cheaters for the best results. (I was born when cams were driven by a chain, or something called a "Jackson Drive"... I'm old.)

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  • Thanks Steve! It's a job I've been meaning to try out for myself, a bit intimidating knowing if it's timed incorrectly... I basically need a new car! – Jay Aug 17 '16 at 8:07
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    How do you bend the belt to check for cracks without removing it? And if you've already removed it, you've done 100% of the work to replace it anyway; the only additional cost is the cost of the new belt which is on the order of tens of dollars... – R.. GitHub STOP HELPING ICE Aug 18 '16 at 3:39
  • @R..Exactly. The force is strong with you. If you can get at it you can do it with needle nose pliers. However, as I mentioned, you really need the KIT: belt, all idlers, tensioner, and waterpump, even if it's driven by the belt backside [eg Subaru]. Putting on only the belt is like jacking up a head and sliding in a new gasket. In every single timing belt failure I've seen, there was always a contributing factor like a failed idler bearing or a failed tensioner. I've NEVER seen a belt break just because it gave up, leaving pristine idlers, tensioners and non-leaky waterpumps. – SteveRacer Aug 18 '16 at 3:50
  • Hey, timing chains are back in fashion you know! I've not had to consider a timing belt for the best part of a decade :-) – RemarkLima Aug 18 '16 at 7:05
  • @RemarkLima I've never been in fashion. But one thing I know... Chains may stretch. Belts break. (Or at least skip) – SteveRacer Aug 18 '16 at 7:59
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As others mentioned: Change it, the belt looks suspicious (especially the position and the side towards the engine) and it is much cheaper than a new engine.

Just for the position of belt on the sprocket:

For certain types of spring tensioners it can happen, during installing, that the spring will get stuck between tensioner and engine block, thereby causing a miss-alignment of the tensioner and consequently forcing the belt out of track. For clarification:

The blue marked part of the spring gets stuck under the red marked part of the tensioner. enter image description here

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Echoing the advice you've already received, change it as soon as you can.

I'm particularly concerned by the position of the belt on the sprocket and what looks to me like a wear line to the left of the belt. I would be happier if the belt was tracking closer to the middle of the sprocket and the wear line suggests to me that the belt is either moving back and forth across the sprocket as it runs or it has changed its position.

Neither of those seem like good signs to me.

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  • Thanks, I was also concerned when I saw that, especially with the bit of fraying on that end. I wasn't sure if it was normal to be that far on the sprocket. Thanks for the input. – Jay Aug 17 '16 at 1:21
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Change it! That belt has wandered from center as is visible by the wear pattern on the sprocket and it looks like the back edge against the head is showing signs of rubbing. This is most likely due to a worn water pump and/or idler/tensioner. Change them all too. You can get away with breakage on a non-zero clearance engine like most Toyota/Subaru's which will just stop running, but things like Honda's and Ford's it spells catastrophic death for the engine. There is almost never any warning that they are ready to snap.. Don't risk it. -Rich

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You could try cost-benefit analysis.

Work out the cost of replacing the belt now.

Work out the cost of replacing the engine (or the car) after the belt snaps and the pistons hit the valves. Also include the wear and tear on your nerves if that happens at speed, and the non-negligible chance of it causing an accident. It's most likely to snap while you are accelerating hard, such as while overtaking (cue nightmares). Then there's the cost of having the immobile vehicle recovered to a garage.

Guesstimate the probablity of the latter event if you delay the cost of the former for too long. It's a fair assumption that if the belt had been replaced recently the vendor(s) would have used proof to support a higher price for the car. So most probably it's approaching or outside its service life.

For anything except a very old car that is used for fairly few miles per annum and that you expect has only another year or two left in it, you'll conclude that in the absence of a service history, it's best to replace the timing belt now. Safety considerations may convince you even for a temporary car of little more than scrap value.

BTW I think there may be some low-compression engines where the pistons can't hit the valves, in which case it's far less traumatic when the belt snaps. So if money is very tight and if you can establish that your engine is definitely in this category, the balance may shift a bit.

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I would assume it hasn't been changed. I have never had a belt changed by a garage without a sticker somewhere on the car stating the mileage and the date (some manufacturers recommend changing after X years even if the mileage is low).

Note, the sticker may not be in the engine compartment. I once had one put on the edge of the driver's door, visible when the door is open - that's a better place than the engine compartment to keep it clean and legible for several years!

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  • +1 for sticker – I even put the sticker on when I change the belts on my own cars, very good suggestion. – dlu Oct 22 '16 at 3:53
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Replace it as soon as you can. A couple cars ago I was in a situation like yours. I opted not to replace it, and the timing belt let go. Completely trashed the engine and totaled the car.

Trust me, shelling out for preventative-maintenance is much, much better than fixing something that's gone wrong. You should try to catch problems as early as you can.

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I'm late to answer, but I'd like to present an alternative opinion to those opinions that I see already here.

Though their may be risk of damaging the motor if the belt fails (interference engine), this could turn out to be a rather expensive belt change. If the engine is not an interference engine or has less than ~120K KM on it, then I'd not change the belt.

The reason that I warn that this job looks like it could get expensive is because the belt looks fine, but the installation was poor. That belt should be in the middle of the gear, not the inside edge. Therefore it has been changed, but by an inexperienced mechanic. Other installation issues, such as overtighting of bolts or damage to the front engine mount or water pump, might turn this job into a quagmire. The belt replacement likely happened at 75K-100K, so I'd change it at ~150K. But not before.

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  • Thanks for the opinion. I've seen some pictures/videos of my same J-Series engine with the timing belt on, and what's more curious is I've seen the timing belt used covers the entire sprocket width-wise... I'm starting to wonder if the right timing belt was used to begin with (could be very troubling). You're right though it does seem like it's been changed but that car is nearing 170k so even then it could still have ~70k miles on the TB – Jay Aug 23 '16 at 0:35
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    With 170k on the clock I would definitely change the belt again, and the water pump too while I'm in there. Good luck! – dotancohen Aug 23 '16 at 6:07

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