Serpentine and timing chain
- Thread starter Riser
- Start date
Register to hide this ad
the_economist
New member
For the drive belts, the owner's manual says your first inspection is at 60,000 miles, and then inspect every 15,000 miles thereafter until you replace it. If it's quiet and no cracks, wait 15,000 more miles and check again.
The timing chain is forever, at least in theory. It's one of the best features of these engines in the 5th Gen 4Runner in my opinion. I ran a 1975 Chevy Sport Van with 300,000 miles on the motor, and the original timing chain was just fine.
The timing chain is forever, at least in theory. It's one of the best features of these engines in the 5th Gen 4Runner in my opinion. I ran a 1975 Chevy Sport Van with 300,000 miles on the motor, and the original timing chain was just fine.
Thank god for the timing chain in these things. I did have a timing chain fail apart on our 02 911. It ****ing killed that motor since it was an interference motor. I'm still bitter about that one. To be fair, a porsche probably has much tighter tolerances than everyday vehicles to perform the way they do.
i didn't feel like spending 15-20k for a used motor on a used 15k car.
i didn't feel like spending 15-20k for a used motor on a used 15k car.
RAD4Runner
Senior Member
Checked youtube for procedure? IF it's as simple as on a 2007 Corolla, approx $40 for replacement belt and it's a 15-minute job.
Jetboy
New member
As a general rule if it's an interference motor from Toyota - it will have a timing chain, if it's not, it will have a belt. Chains last a lot longer obviously, but they stretch a bit and are less accurate. When you have variable valve timing on the cams - chain accuracy doesn't make much difference. So a chain makes a lot more sense. IIRC most very high mile toyota engines have changed the timing chain around 500,000 miles. So that's what I would kinda shoot for.
I have no idea on the belts. I changed the belts on my last 4runner at the second timing belt (180k) for the first time. They were pretty worn, but they never gave me any trouble for nearly 200k miles. At 180k I replaced all the rubber parts in the engine bay - hoses, belts, etc. Just as maintenance. If I own my current one that long I'll probably do the same around 150k miles.
I have no idea on the belts. I changed the belts on my last 4runner at the second timing belt (180k) for the first time. They were pretty worn, but they never gave me any trouble for nearly 200k miles. At 180k I replaced all the rubber parts in the engine bay - hoses, belts, etc. Just as maintenance. If I own my current one that long I'll probably do the same around 150k miles.
That's good to know about what kind of motor has the chain or the belt.
I had a 1987 camry that had a belt that had a couple worn teeth and wouldn't start. A new belt was put on and i was good to go. No damage.
I had a 1987 camry that had a belt that had a couple worn teeth and wouldn't start. A new belt was put on and i was good to go. No damage.
03_4x4Runner
Senior Member
The 4.7 V8 used in the 4th gen 4runner is an interference motor and uses a timing belt.
BlackWorksInc
New member
So funny thing about "life of the motor" because usually if the chain takes a shit it's gonna end up totalling out the motor once you start adding up the costs of a new cover, guides, whatever else the flinging metal put a hole in, ect.
You'd think that, but the 3.0L & 4.7L engines were interference engines per Toyota's nomenclature and they were belts. I think 1 4 cylinder was as well, but I forget which one.
~
All that being said, if you're not having issues with the timing chain don't worry about it. I'd only bother replacing the chain & guides if you were doing a timing cover reseal or had the engine apart for a while. The reason is because the guides will dry out some and when the engine is put back together after it's had that many miles the plastic on the guides can fracture and take out the assembly (had it happen to me once...)
So don't worry about the chain, it's not a VW it most likely will not grenade on you.
03_4x4Runner
Senior Member
So funny thing about "life of the motor" because usually if the chain takes a shit it's gonna end up totalling out the motor once you start adding up the costs of a new cover, guides, whatever else the flinging metal put a hole in, ect.
You'd think that, but the 3.0L & 4.7L engines were interference engines per Toyota's nomenclature and they were belts. I think 1 4 cylinder was as well, but I forget which one.
~
All that being said, if you're not having issues with the timing chain don't worry about it. I'd only bother replacing the chain & guides if you were doing a timing cover reseal or had the engine apart for a while. The reason is because the guides will dry out some and when the engine is put back together after it's had that many miles the plastic on the guides can fracture and take out the assembly (had it happen to me once...)
So don't worry about the chain, it's not a VW it most likely will not grenade on you.
I have a question for you. My neighbor has a 2005 Tundra with the 4.7 and only 47k miles. I have been telling him the timing belt needs changed every 10 years or so for age but he does not believe me. What would you tell him?
BlackWorksInc
New member
9yr/90k is the service interval. That polymer belt degrades, you can't even tell from a visual inspection. I used to have a belt that looked almost new but snapped from age. The rubber/plastic that belt is made from is different than say your drive belt, it doesn't crack up and visibly degrade as much as your drive belt does.
I'd highly suggest replacing the timing belt, particularly if the water pump has been leaking at all because the coolant degrades the belt faster. It's up to him but if it were my personal vehicle I'd do it; I changed my timing belt at 100k on my 4Runner.
03_4x4Runner
Senior Member
Thank you. I changed my timing belt on my old 4th gen at 9 years and 75k miles. A lot of people said I was a fool. I will show my neighbor what you told me. If it were mine I would definitely change it and the water pump and be good for another 9 years.
kenwilliams0803
New member
Blackworksinc is right. Time can degrade the material as bad or worse than mileage. I wouldn't go more than 10 years on a timing belt. You can, but you are just asking for it to let go on you one day.
Sent from my SM-G900V using Tapatalk
Sent from my SM-G900V using Tapatalk
zerowkul98
New member
Ive owned two 4.7L V8 4runners, and I did the 90k on both, and they had the same problems when I had them at the dealership getting the work done. On the outside, there was no sounds, leaks, etc. When the front of the engine was taken apart, they BOTH had leaking water pumps. There was a void-area where coolant would leak and crystalize before it would show outside to the human eye. Id always have $2000 set aside in my budget to get it done, and replace the timing belt, water pump, serp belt, etc etc.
Now, I have a 2013 Sequoia. Going out today to look at 2016 Trails, and a 2017 TRD Off Road. New job with more of a commute, and pissing through gas with a 5.7L V8 is not working for me.
Now, I have a 2013 Sequoia. Going out today to look at 2016 Trails, and a 2017 TRD Off Road. New job with more of a commute, and pissing through gas with a 5.7L V8 is not working for me.
BlackWorksInc
New member
Yeah, seems like by the first timing belt service those water pumps have been or are starting to leak. Weird thing is after the first genuine Toyota water pump they don't seem to leak by the second time, not sure why; but honestly if it were my vehicle I'd still just do a water pump/timing belt combo regardless due to labor.
Belt Shredded at 44K Miles
Sorry to piggy back on an older thread. This is the most relevant I can find to my question.
My wife was driving our '16 Limited yesterday and suddenly the battery light came on and she lost power steering and A/C. 44K miles, serviced on schedule at the local dealership and no off-roading or otherwise rough driving.
Dealership tells me that the belt is shredded and "maybe something came off the road to knock it off". As a result, there are shreds lodged in various places and the harmonic balancer, front seal, and tensioner pulley all need to be replaced. They told the extended warranty provider the same story and they won't cover the repairs because they don't cover belts or damage associated with them.
I'm calling BS on all of it. At 44K miles, the belt should not shred and I challenged them to explain how something came from the road with precision and force enough to knock the belt off, which they of course can't do. I feel strongly that something else like a leak or pulley issue is more likely the true original culprit, at a minimum it's an equivalent assumption to "something came from the road". Anyone had a similar experience or have advice to offer?
Sorry to piggy back on an older thread. This is the most relevant I can find to my question.
My wife was driving our '16 Limited yesterday and suddenly the battery light came on and she lost power steering and A/C. 44K miles, serviced on schedule at the local dealership and no off-roading or otherwise rough driving.
Dealership tells me that the belt is shredded and "maybe something came off the road to knock it off". As a result, there are shreds lodged in various places and the harmonic balancer, front seal, and tensioner pulley all need to be replaced. They told the extended warranty provider the same story and they won't cover the repairs because they don't cover belts or damage associated with them.
I'm calling BS on all of it. At 44K miles, the belt should not shred and I challenged them to explain how something came from the road with precision and force enough to knock the belt off, which they of course can't do. I feel strongly that something else like a leak or pulley issue is more likely the true original culprit, at a minimum it's an equivalent assumption to "something came from the road". Anyone had a similar experience or have advice to offer?
DougR
Member
I think it would be a good idea to repost and start your own thread. Your issue involves different parts. The next post in this thread is redirecting back to the original topic. You'll get very few replies if you don't repost.
This vehicle has a front skid plate. It's impossible for an object to bounce off the pavement and up into the serpentine belt. (Notice how they said "MAYBE something came off the road..." No way. Put the skid plate back on and have them show you how something could have bounced through the skid plate and into the belt.
It would be helpful to see photos of the damaged parts, especially the harmonic balancer and tensioner. Has the dealer taken it apart to give you an estimate? If not, how would they know the front seal (located behind the harmonic balancer) needs to be replaced? Is it leaking oil?
Extended warranty doesn't cover parts that incur normal wear. Obviously, this is not an instance of normal wear. I would press for warranty coverage because the harmonic balancer may have failed first. Did it separate into two pieces? Is the outer part loose? Pictures would help.
If something came up and lodged between the belt and a pulley, then one or both pulleys should show fin and outer edge damage. If not, then one of the pulleys failed which caused the belt to shred. Is the tensioner in pieces? Did a piece of the tensioner hit the harmonic pulley? A tensioner failure should not lead to a harmonic balancer failure. We have to see detailed photos at multiple angles of the tensioner and harmonic balancer.
This vehicle has a front skid plate. It's impossible for an object to bounce off the pavement and up into the serpentine belt. (Notice how they said "MAYBE something came off the road..." No way. Put the skid plate back on and have them show you how something could have bounced through the skid plate and into the belt.
It would be helpful to see photos of the damaged parts, especially the harmonic balancer and tensioner. Has the dealer taken it apart to give you an estimate? If not, how would they know the front seal (located behind the harmonic balancer) needs to be replaced? Is it leaking oil?
Extended warranty doesn't cover parts that incur normal wear. Obviously, this is not an instance of normal wear. I would press for warranty coverage because the harmonic balancer may have failed first. Did it separate into two pieces? Is the outer part loose? Pictures would help.
If something came up and lodged between the belt and a pulley, then one or both pulleys should show fin and outer edge damage. If not, then one of the pulleys failed which caused the belt to shred. Is the tensioner in pieces? Did a piece of the tensioner hit the harmonic pulley? A tensioner failure should not lead to a harmonic balancer failure. We have to see detailed photos at multiple angles of the tensioner and harmonic balancer.
Last edited:
flyrv9
New member
I had the timing belt and water pump changed on the 4.7 in my Tundra at 90K miles. The original interval was 70K miles; but Toyota extended it to 90K. Changing the water pump is a good idea for both age and access reasons. I had the dealer do it and had no issues. Truck has 130K now.
83Mule
New member
At 120+ degrees here (we are on our 81st straight day over 100) I am conservative on the serpentine and never go beyond 50K no matter what it looks like and keep a spare in the truck too. $22 for a Gates on Amazon it is cheap and easy to know my Wife can cruise to Phoenix through the Wasteland with confidence.ray2:
ray2:
