Go back to the Mercedes forums and read again lol! There a LOT of issues with most of their engines and even the M113 has problems. If the slack exceeds the interval of the drive gear with the lowest interval between teeth in degrees you are running the risk of chain jump. That's just a fact and why engines have a max spec for offset adaptation since while it "could run fine" over 5* for an EA888 you are always running the risk every time you use it for the chain to jump and you get the typical failure. I explained all this earlier in the thread.

The LS460 hesitation issue is chain stretch so every single thread we have on that here is a chain issue. Every UR engine I've had in or scanned with the hesitation has out of spec adaption values and in two cases had pending codes for cam/crank correlation.

You are also assuming that people change oil when it should actually be changed and not just when the manual says to. They don't and you know they don't. Also really ask yourself if most shops out there really know what they are doing and would even be willing to deal with half the stuff I do?

Most of the time they just replace the entire engine instead of replacing the actual cause of problems

 

So the same chain drive system as the standard cars are having issues?

The tunes have no effect on the chains btw, spring tension is the same, cam profiles are the same, redlines are the same, oil pressure is the same, etc......

The reason the AMG guys complain more if because they use the cars to ability far more than the common buyers do so a slight hesitation or issues bring in more notice. Most normal drivers never really use the car to design but the AMG/S/M guys very much do and are far more obsessed with things working correctly.

 

So explain failures when the 10k oil change intervals are followed or in cars still in warranty?

Let me out it another way.....if belts are really worse than chains and cheaper why don't all makers just use them? The first change is past warranty period anyways so why do they still use chains?

Cost. Chains are cheaper to implement and produce since it's just a bunch of links and pins. Belts have to be designed per engine and require a lot more R&D and accommodations for service in the packaging.

A chain lets you skip all that and slap a "lifetime" stamp on it like modern transmission fluid does. Even when if you call the factory/company that makes the trans and they tell you do not exceed 60k miles without service. Call a chain company and ask them what the lifespan is......it's not infinite and if you follow a car manufacturer suggestion it will last the "lifetime" of the warranty period.

 

I did, there are some issues but its not widespread, more common in AMGs. Most people with high mileage cars have their original chain and have no issues at all.

Yet people are driving those cars and they are providing good solid transportation. Every case of chain stretch does not require replacement of the timing chain. I texted my Lexus mechanic, he has never seen a failed chain in a Toyota or Lexus. Also texted my MB mechanic and he said that its more common in the AMGs but most people never have any problems. Honestly? If most people never replaced their timing BELT they would be just fine.

I know both the mechanics I texted would and do.

Then where are all the people with engine replacements?! They don't exist.

A tune absolutely places the engine in general and all their components under more strain, timing chain included.

That makes zero sense.

What costs more to buy, a timing belt or a timing chain? Timing chain kit for the LS460 is $1,300 for parts. The belt kit for an LS400 is $300.

Toyota would not have gone to a timing chain unless it made the product better

 

This video is pretty much what my Lexus mechanic said:

 

You are a shop owner. I look at the situation from a lay person, owner who happens to like cars.. (predominantly Toyota and Japanese cars)

my chain cars have a combined 25 years (Matrix 2009, Corolla 2014 and 4Runner 2021) of service on the road. Combined miles are 262,000 miles (Matrix 158,000, Corolla 97,000, 4Runner 7000 miles). I have had no such issues or concerns with the timing chains. Why would I “preemptively” want to change them out?

I am using common sense and reason in the above. Logic is being applied above….

why would I call a timing chain manufacturer?


Our independent mechanic who services our Matrix has never spoken or mentioned timing chains. (Left my belt 4.7 4Runner out of the equation).

 

And it certainly may be that certain makes and certain engines have issues with timing chains, but that is an issue with the engineering of those particular engines...the "chain" as a concept is not the issue.

Nothing lasts forever, but the vast majority of people who own vehicles with timing chains will never have an issue with their chain as long as they maintain the car properly.

 

This makes sense. It would be good to know if there are any car engines out there that actually have a timing chain service or replacement interval.

At a certain point. A timing chain replacement might warranted..some will do it … some will just trade in their vehicle

 

None that I have ever seen

 

On newer cars that have dual VVTI it is possible for the engine ECM to advance or retard the cam timing for each cam independently to adjust for chain/belt slop or small mechanical fitment issues for cam vs crank correlation.

But on older cars that have only one cam per cylinder head electronically adjustable this brings a late timing to the cam not under computer control.

While the ECM can adjust for the cam that is electronicall controlled thru VVTi or other tech there comes a point when it can no longer adjust out the slop and throw a code aka Cam vs Cranshaft timing is out of max allowed spec.

This spec will be decided by the oem as to what is considered "normal" tolerance.

BUT-
I'd think this would be seen in lower performance and gas mileage(while still in spec).
* This is off the top of my head in theory so my apologies if I'm wrong, just ideas.

PS- good video SW, he did admit these chains break sometimes which on a 2GR engine in a FWD like the RX350, it's drop the engine time and if the car has high mileage and older it could mean junkyard time if not cost effective to repair. This is elimiated with a Timing Belt thus my theory of product lifetime built into the design. I know it sounds sinister, but that's my theory so far because I see it on machine electronics I work on.

 

But he also said he has never seen one fail in a V6...and the only ones he has ever seen need replacement in any Toyota or Lexus have been when there is an external factor...which is exactly what my Lexus mechanic said.

So, why worry about the repair procedure for something that maybe has a 1% chance of failing? There are many things that could fail and would destroy the car, but we aren't worried about them because it would be extremely extremely unlikely for something like that to happen.

With a timing belt, you need the consumer to replace the timing belt...which maybe they do once but not every 90k miles. My 03 ES300 had the timing belt replaced at 90,000 miles and that way maybe 2007, and its still on that same belt 15 years and 130,000 miles later. Makes no sense to replace it because the car is only worth maybe $1,500. So, everything has a life. If the timing belt snaps it'll get scrapped...if it had a timing chain I have no doubt it would be still fine today, and I wouldn't have had to pay $1,500 to replace it in 2007.

This is a 97 LS400 with 250,000 miles on the original timing belt. 26 years on the original belt! Way more of them are like this than have had the belt regularly replaced:

 

I hear what you are saying but it makes me wonder- if the belt can go 250k miles on a V-8 why bother with an oiled chain setup?
Why really ruin the design with cheap plastic chain guides and parts, done by some oems?

Yeah I could google it to see what everyone on the internet thinks but I rather hear ideas from my fellow CL members since I really don't know.

Chain: expensive repair
Belt: lower cost repair and does not require engine removal on cars with tight engine bay space.

There must be some upsides if oem's use chains but if not why do they do it is my question that I wonder about.

 

Toyota has gone from chains to belts now back to chains. Some Toyota's even had a dual-row timing chain as it was a double chain in the 1980s. Tacoma and Hilux come to my mind. And then Toyota removed the second chain to cut cost.

I am pretty sure Toyota went to chains for two reasons, one is that they are now maintenance free, it is very hard to convince anyone in 2023 that you have an engine that requires a timing belt replacement for $500, oh and also you should change out your water pump too...so that is now a $1000...oh and you also need to be without a car for a FULL DAY. (not gonna happen) number two, the power rating of cars today are far higher...a belt is not gonna cut it...especially when the entire industry has gone to chains. Toyota engines with belts were historically behind the power ratings compared to the American brands in the 1990s and 2000s...

 

Because at any moment that belt could snap and ruin the interference engine. That belt is WAY beyond its life. The difference is the belt is a wear item which WILL cost the owner $1,000 every 90,000 miles. The chain is not a wear item that will likely last the life of the car and may in a very unlikely circumstance require replacement.

Thats a huge difference

 

i have no idea how that belt didnt snap. Even if a car doesnt reach its mileage, a timing belt can age out because its rubber also