Good Info About Fluid Maintenance & More

Actually, chains wear. They get looser and longer as a result, but they don't technically stretch.

 

What happens is when the guides wear/disintegrate the chain gets loose and eventually saws a slot into the water jacket/timing chain cover……water and oil don’t mix. I did mine at 150K and there were ‘saw’ marks in the cover. Pieces of the plastic chain guides have been in the oil pan for about 20years now.
Heat cycles make the plastic guides weak and brittle.
There are aftermarket guides made similar in construction to drum brake shoes that last.
I replaced the chain even though I could not tell the difference between the new and old……same length and side-side play.

 

I suppose I should count myself fortunate that none of that happened to me for so many miles.

 

Sorry, wasn't trying to be a jerk. Some folks think they do really stretch.

 

Not at all. I'm saying that at 100K, it's not likely to be stretched enough to make a difference. Maybe after 200-300K It would become necessary. I'm just going by the fact that some people are putting 200-300K on these without any issues. The tensioner should be able to compensate for a small about of stretch (wear).

 

This is a great post and a great rebuttal to the asinine "some schmuck with a high school education" post.

I've seen probably the same amount of lazy idiots with college degrees as lazy idiots without college degrees, but it's the lazy idiots with college degrees that make the big uh-ohs since they're the ones in the position to make the big uh-ohs. I've also seen lazy idiots with college degrees in charge of other lazy idiots with college degrees, and if the cycle of uh-ohs could be adapted into a perpetual motion machine some lazy idiot with a college degree would get a Nobel Prize.

 

People think engineers are making all the design decisions.

That's mis-guided.

The bright young MBAs up on Mahogany Row have a HUGE say in the design process. They hold the purse strings.

It's called "cost engineering" when it comes down from on-high. What that means is that engineers have to work within budget and schedule parameters not set by technical people who understand what they are building, but by bean counters who don't worry about you needing a universal joint in your left elbow to change your oil.

I carried the tools for many years as a high voltage technician before I earned my EE. So yeah, I gripe about maintenance and repair problems due to poor design. But more times than not I see "if we save a nickel on each unit..." as a big source of problems...

 

The noise you heard was the chain slapping the timing cover.
It is about the only problem(common) with the engine.

 

I would agree with this. Fortunately, at least from my perspective, Toyota has more safeguards in place to ensure that quality and reliability isn’t completely abandoned as with possibly other OEM’s.

 

This is what I was trying to say. As a mechanical engineer (in a completely different world than automobile design), I am constantly being asked to compromise from the best design approach to something that is passable but will cost less money...(my favorite is when they ask me to do something that would violate code and I get to tell them no...)

 

Don’t leave out politicians.
They mandated the illustrious 5mph bumpers in the 80’s.

 

the biggest thing for me is the trans oil. I read all the posts you all make about doing it, but its definitely out of my wheelhouse. Not comfortable doing it myself, and the dealerships... one says lifetime and won't touch it and the other can't do an oil change without overfilling it so, I legitimately have no place to get it done. I read a ton of posts on it here and other places online and there are some people with large post counts with many helpful accounts stating changing the oil after 100k or so isn't worth it and leads to trans issues. Some of those guys (albeit few) don't do the trans fluid and have had no issues going into 200k miles. I am torn with taking a gamble on someone who thinks they can do it at a premium that I don't trust, and just rolling the dice. I don't know if I will have the 4Runner that long but the idea of taking care of it like I will own it til it dies is appealing. random thought. Thanks.

 

I was weary of doing it myself but it's so easy using the pump in the trans and a bucket.

 

When Should You Replace Your Toyota And Lexus Timing Chain?
Explains why one should be replaced, but has nothing to do with stretching.

Now the P0016 and P0017 a more simple solution here and why:
Owner was told to get new engine or junk it. Solution?
see here: https://youtu.be/BuAlbq4AkFw

 

Can you sum up what the issue was. I'm trying to skip to the conclusion but now I'm just annoyed that I gave that guy another view.

 

Good videos. First one basically says toyota timing chains dont have a service interval. If he does vvti work, he always inspects the chain, because vvti failures can ruin chains. When he replaces chain, guides and tensioner are replace too.

The second vid is basically a “buyer beware” on lazy workmanship.

 

Thank you!

I seem to have an issue with YouTube guys.

 

I generally do to. But some like Car Care Nut and Tinkerer are pure gold.

 

...Not exactly but yes...it was an oil control valve..... lazy because timing chains get replaced when not needed most likely.

 

The engineers with advanced degrees trained (and paid...) by Toyota certainly know more about the inner workings. But are they motivated to give a damn about us simps who drive the things....that's the question.

 

Said engineers designed hydraulic tensioners to take up chain slack as it stretches but they have limitations. Although I have never seen a chain failure in the 13 years I’ve owned a 1GR, the chains do stretch.

 

….up until the warranty expires anyway.

 

I had the transmission, transfer case, front/rear diff fluids changed, and a front brake job done this past Monday/Tuesday. Had to remove the aftermarket skid plates. (the mechanic was not pleased). Cost was a tic over $1,000. Work was performed at an independent shop I have been going to for 30ish years. $229 seems about right. The shop rate here is $135/hr.

EDIT: Work was done at 53,000 miles. Owner told me the transfer case and diff fluids were inky black, with very few "sparkles." Sparkles are bad. Transmission fluid looked O.K.