Another dead chain
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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 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.
If Steve is fine with a decrease in performance and odd spots in the powerband or thinks that's normal I can't help with that.
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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.
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.
Belts are cheaper to buy replacements for since it's an expected part you will replace and stock is made for it. Chains are assumed to be "for life" and so aftermarket's don't really support them nearly as well and that's increased cost it's to be expected. This also allows aftermarket companies to price higher due to the OE parts being so costly, they can get away with only 10-20% cheaper.
Actual chain snap is rare but not needed to kill and engine, I've only had 4 actually snaps but many kills valves just from being over max spec.
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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
Thats a huge difference
Do you know what that value is for your engine and how to check it? I showed mine and know the limits and keep track of them just to ensure I don't have response issues or delays in power.
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Everyone is raising good points and I can see the arguments on both sides.
One thing I do know is many mechanics don't want to fool with a car that isn't throwing codes.
I was struggling with what felt like a misfire and wasn't sure what the problem was and took it to a mechanic for a 2nd opinion and paid a diagnostic fee and they handed my keys back and said car runs great.
Car was not running great and I could feel the misfire at idle and told that to the shop owner to which he replied, "it's normal and until it throws a code don't worry about it or bother bringing it in".
Maybe there is no money in real diagnostics or maybe they just like the easy money jobs that don't require a lot of work to diagnose, really not sure.
Are most of the chains you see after the damage is already done or they bringing them in after getting bounced around from shop to shop with no answers like they did me.
All I know is if a car isn't throwing a code seems like most mechanics don't want to touch it anymore aka not many Scanner Danners out there.
One thing I do know is many mechanics don't want to fool with a car that isn't throwing codes.
I was struggling with what felt like a misfire and wasn't sure what the problem was and took it to a mechanic for a 2nd opinion and paid a diagnostic fee and they handed my keys back and said car runs great.
Car was not running great and I could feel the misfire at idle and told that to the shop owner to which he replied, "it's normal and until it throws a code don't worry about it or bother bringing it in".
Maybe there is no money in real diagnostics or maybe they just like the easy money jobs that don't require a lot of work to diagnose, really not sure.
Are most of the chains you see after the damage is already done or they bringing them in after getting bounced around from shop to shop with no answers like they did me.
All I know is if a car isn't throwing a code seems like most mechanics don't want to touch it anymore aka not many Scanner Danners out there.
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From: Maryland
On an old car like my 03 ES300, there are LOTS of things that can be replaced. It leaks oil, the timing belt needs to be done, the struts are old and soft, the list goes on...but it runs fine for the small use my Mom has for it and its not worth doing all of that.
Do you know what that value is for your engine and how to check it? I showed mine and know the limits and keep track of them just to ensure I don't have response issues or delays in power.
Last edited by SW17LS; May 2, 2023 at 12:57 PM.
Lexus Fanatic
Joined: May 2012
Posts: 68,092
Likes: 3,870
From: Maryland
Everyone is raising good points and I can see the arguments on both sides.
One thing I do know is many mechanics don't want to fool with a car that isn't throwing codes.
I was struggling with what felt like a misfire and wasn't sure what the problem was and took it to a mechanic for a 2nd opinion and paid a diagnostic fee and they handed my keys back and said car runs great.
Car was not running great and I could feel the misfire at idle and told that to the shop owner to which he replied, "it's normal and until it throws a code don't worry about it or bother bringing it in".
Maybe there is no money in real diagnostics or maybe they just like the easy money jobs that don't require a lot of work to diagnose, really not sure.
Are most of the chains you see after the damage is already done or they bringing them in after getting bounced around from shop to shop with no answers like they did me.
All I know is if a car isn't throwing a code seems like most mechanics don't want to touch it anymore aka not many Scanner Danners out there.
One thing I do know is many mechanics don't want to fool with a car that isn't throwing codes.
I was struggling with what felt like a misfire and wasn't sure what the problem was and took it to a mechanic for a 2nd opinion and paid a diagnostic fee and they handed my keys back and said car runs great.
Car was not running great and I could feel the misfire at idle and told that to the shop owner to which he replied, "it's normal and until it throws a code don't worry about it or bother bringing it in".
Maybe there is no money in real diagnostics or maybe they just like the easy money jobs that don't require a lot of work to diagnose, really not sure.
Are most of the chains you see after the damage is already done or they bringing them in after getting bounced around from shop to shop with no answers like they did me.
All I know is if a car isn't throwing a code seems like most mechanics don't want to touch it anymore aka not many Scanner Danners out there.
Do you think the customer who has that 97 LS400 the CarWizard did that video on is going to have all that work done? No.
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