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I believe that not only do the guides wear and/or break, the chain stretches enough that even with new guides/tensioner installed, it can skip a tooth. I'm pretty sure that the best thing to do is replace the chain AND guides/tensioner.
You should be able to get a decent look at them with the valve cover off. That being said, I'm having a hard time seeing yours in your pictures. I've heard of the chain stretching and skipping a tooth too. I agree with Pat, there's no reason to replace the guides and not the chain and tensioner.
The guides break because of the stretched chain. That's why there's a bit of a debate over whether metal-backed guides, while durable, are actually helping to hide the underlying issue as the chain ages.
Putting new guides on to replace broken ones, and not installing a new chain and tensioner at the same time would be a horrible plan
It's a consensus that around 100k
you should do the whole tamale
I think it's fairly safe unless you hear the chain rattling on the timing cover... then you better getrdun
The guides can break due to the plastic getting brittle with time and thermal cycling and/or a worn chain is slapping against the guides.
It looks like the top of your driver's side guide is broken.
Technically, the metal in the chain doesn't stretch, it is all of the pivot points in the chain wearing out causing play in each joint, giving you a longer or "stretched" chain.
If I found any of my timing chain guides broken, I would replace the whole timing set (chain, tensioner, both guides, cam sprocket, crank sprocket).
Generally, the timing chain guides wear out or break before the chain itself breaks, however the chain could be worn enough where the tensioner maxes out, and the excessive play in the chain breaks the guides, but the only symptom you might see is the broken guides, even if the chain and the tensioner were the initial cause of the failure. I think this is what actually happens more than people realize.
Also, if the driver's side guide completely breaks, the chain will start to wear through the timing cover and could eat its way into the water passage behind the cover where the water pump is.
I would replace your timing chain set with an OSK kit, or a kit from 22RE Performance.
I don't think anyone has suggested replacing the guides and not the chain.
Chain replacement is pretty invasive and labor intensive, so the idea is to inspect and replace parts if they're worn past spec or broken. Not all engines wear at the same rate, otherwise we'd all do full rebuilds at the same # of miles.
For this particular engine, there's no clear clatter when warm, but when cold there is some extra noise (clatter???) between 2,000 and 3,000 RPM for the first few minutes but it's unclear where that comes from.
It's a consensus that around 100k
you should do the whole tamale
I think it's fairly safe unless you hear the chain rattling on the timing cover... then you better getrdun
no, not really. there is plenty of evidence of original timing chain components running well into 300K miles. obviously, the age matters, if that 300k takes 30 years, that's a long time vs putting 300k on in 10 years.
but, an engine in good condition, that gets routine oil changes and other maintenance, and is driven regularly, should easily eclipse 100k for the timing set.
I think 100k is a recommended replacement schedule. Its not the max life of a chain and guides.
A lot of it also has to do with driving habits and type of transmissions. Manual trans and hard shifting will wear a chain quicker.
I think the 100k thing is because the 22re is an interference engine so if the chain goes, you have big problems.
From my experience with these engines, a brand new chain hardly makes any noise, cold or hot. My chain has 150k on it now and I hear it cold, quiets down warm but still makes me nervous.
I think once you look down there and see youre losing pieces of your guides, its time to save up and plan when and how youll replace it. The job isnt hard if youve got some experience.
I think 100k is a recommended replacement schedule. Its not the max life of a chain and guides.
A lot of it also has to do with driving habits and type of transmissions. Manual trans and hard shifting will wear a chain quicker.
I think the 100k thing is because the 22re is an interference engine so if the chain goes, you have big problems.
From my experience with these engines, a brand new chain hardly makes any noise, cold or hot. My chain has 150k on it now and I hear it cold, quiets down warm but still makes me nervous.
I think once you look down there and see youre losing pieces of your guides, its time to save up and plan when and how youll replace it. The job isnt hard if youve got some experience.
oh, i understand. and i clearly got very lucky when my chain snapped a few months ago. zero issues, other than replacing the brand-new timing set and brand-new headgasket.
but, a typical timing belt runs 60 to 120K as a recommended interval. the evidence is out there that the 22re chain is capable of providing significantly more miles than 100k, as long as other routine stuff is done. and, to me, because the head gasket should be changed when the chain is replaced, more than 100k is the goal.
Like I said above, my chain has 150k on it now. Id be happy to do a timing chain and HG every 100k and not worry about 2 major sources of engine failure.
But its a question of time and money, especially if its your daily driver its hard to have it off the road for a week or 2
Like I said above, my chain has 150k on it now. Id be happy to do a timing chain and HG every 100k and not worry about 2 major sources of engine failure.
But its a question of time and money, especially if its your daily driver its hard to have it off the road for a week or 2
it IS my dd, but i own a lot of vehicles. 3 1987s, 2 1988s, a 1989, a 1975, and a 1948. i almost always have another vehicle available to run when my red '87 is "up" for repairs.
for that '87, which i purchased in may 2013, i've put 101k miles on it (it has 198K+ total miles). i believe that the daily use, and regular maintenance, will allow more than 200k on the chain/head, all things being equal. don't let it run low on coolant, don't let it run out of oil, change the oil, etc. i'll see how that goes, since i will still own it in 10 years.
many of my neighbors wonder why i have so many cars. i can register, inspect, and insure all seven for less than they can typically deal with a single 2017 or later vehicle. by a LONG shot.
As I recall, when I removed the valve cover and took a look, I could see that the passenger side guide was gone, and on the driver's side had two parallel grooves milled into the timing cover. Nice clean grooves about 1/8' deep or so. I used to have a couple of pictures of the gooves in the cover, but they're gone. 155,000 miles. I had gotten the pickup from my brother a while earlier. I did some checking because I didn't like the rattling sound it made from a cold start.
So it seems to me that the timing chain is tensioned by a device that takes up slack when a plunger mechanism extends and maintains tension on the chain when engine oil pressure is developed. So, no oil pressure at first after a cold start, hence the noise at first. When the slack progresses enough, I guess the plastic fails and then you get the rattling of the chain slapping. Maybe its a good thing... the noise like a wake-up call.
With a couple of how-to-do-its I found here, I did mine at home, although working on old cars ceased being enjoyable for me along time ago. I used a combination of aftermarket and factory parts. Doing it again when/if I have to, I will spend a little extra and buy all factory or genuine Japanese parts. I wouldn't use metal guides. I was able to sneak the cover off and back on very carefully without damaging the head gasket. I just left the plastic in the sump. I half-a$$ed the damper off, and had to buy a new one cuz a new vibration had showed-up when I took it for a spin around the block after i got it all back together.
If the chain is eating into the aluminum cover, I would imagine an oil analysis would show high Al and maybe some alloy metals.
To late, tired or lazy to dig out the service spec. It's something like 120k to inspect the chain. To do this you've got to spend about six(?) book hours to measure the chain and tensioner @100+$/hr I'm just gonna say replace the parts and eat the $200 unless I don't expect to live/own it in five to ten years.
"Can the timing chain guides be reasonably inspected by removing the valve cover? Or by some other method?"
Reasonably? The KEY word here.
IF both guides are intact that's a good thing.
can you tell how grooved or brittle they are... no.
is the tensioner full extended? Hard to tell from looking down thru the head.
It's kind of 22re Russian roulette...
it's got 150k miles, but the guides LOOK good. Do I mess with them?
it's got 100k miles and you can hear the chain hitting the cover. You better do something ASAP!
NO really good way to know UNLESS you've already swapped the plastic guides for the metal ones. Then that nightmare is over! Just my two cents.
Last edited by 87-4runner; 01-06-2021 at 07:12 AM.
Like I said above, my chain has 150k on it now. Id be happy to do a timing chain and HG every 100k and not worry about 2 major sources of engine failure.
But its a question of time and money, especially if its your daily driver its hard to have it off the road for a week or 2
this can be done in a day easily,
I could probably do it in about 4 hours now that I've done about 6 times in a row...
Once you've broke the crank bolt and know the little tricks it's not a bad job.
It's the not knowing that's really nerve wracking
I had to pull my TC trying to stop leaks, although once your that far along the rest is s piece of cake.
One trick I've used is to slide good sized flat blade screw drivers (2) thru the cam sprocket and rest them both on the rocker arm (one over and one under) next to one of the head bolts criss cross the screw drivers to hold the timing chain in place while you torque the crank bolt and the cam bolt.... I've done it several times. My rig is an auto so other methods won't work like the manual Trans method
Last edited by 87-4runner; 01-06-2021 at 12:21 PM.
this can be done in a day easily,
I could probably do it on about 4 hours now that I've done about 6 times in a row...
Once you've broke the crank bolt and know the little tricks it's not a bad job.
It's the not knowing that's really nerve wracking
It all depends on experience. If someones posting here abt it, Im assuming theyre not too confident about the job. If you dont know all the tricks, 4 hrs can turn into twice that. But I agree, when I did my first one I was scared to get in there. Then you realize its just a bunch of nuts n bolts
01-05-2021, 11:51 AM
