nonseize engine....
any techies know for sure.....
my hunch is we have the old school timing BELT, and that its like the older 1992 Celica and the engine doesnt explode when the belt snaps.

thanks in advance

The only inexpensive cars I know of that use a chain instead of a belt are Nissans. But this is pure speculation on my part.

your right Nissan has been using chains since 1998 or so on all their v6 and 8's.

not too sure about the lowly 4 bangers.

the MAIN thing is if its a full seize engine like Nissans are.

unless it s a non seize design, you can kiss 4 thousand bucks goodbye in repairs the belt OR chain for that matter snaps.

party on

it's a chain. I downloaded one of the Service Manual copies that was floating around and thumbed through it.

My 2000 celica gts had a chain as well.

Sweet!
I'm pretty sure my buddies SER Spec-V has a chain, and it's a 4-banger.

thats sweet news Epstein,
I cant belive what a bang for the buck this car is.





nice job TOYOTA, errrrr Scion



oh and for 2 points, is it a non seize engine to boot? PLEASE Help me hehe

nonseize engine....
any techies know for sure.....
my hunch is we have the old school timing BELT, and that its like the older 1992 Celica and the engine doesnt explode when the belt snaps.

thanks in advance

Actually they used tC becase xC (to match the xA and xB) was already used for another model of car, I can't find the article again, so I can't remember which car it was.

It does, however have a timing chain. I haven't gotten the shop manual for it as of yet, so I am not sure if it is an interference engine yet . I thought that the Camry engine was not an interference type, but don't quote me on that one. For those not familiar with the term, interference means broken timing chain\belt = bye bye valves and pistons :-)

All Toyotas use chains except a few of the full-size SUVs from what I remember.

your right Nissan has been using chains since 1998 or so on all their v6 and 8's.

Anything with the vg33 V6 has a belt. This includes Frontiers and Xterras as well as a lot of Pathfinders and Quests.

The tC is timing chain, non-interferance engine (will run if chain breaks) The xC was scratched because volvo already had rights on it.

The tC is timing chain, non-interferance engine (will run if chain breaks) The xC was scratched because volvo already had rights on it.

No it will not run. It won't bend all the valves, but the car won't move.

thats sweet news Epstein,
I cant belive what a bang for the buck this car is.





nice job TOYOTA, errrrr Scion



oh and for 2 points, is it a non seize engine to boot? PLEASE Help me hehe

It doesnt matter if it is a chain or belt to be an "interference engine"
its all about it having the overhead cam, so yes, it will mess the valves up if it snaps/breaks...as far as I know at least...

my 91 nissan nx which had the sr20de in it had a timing chain, most of time you had to replace the motor b4 the chain :D

yes, tc's com with a chain, not a belt

Yes i sold for nissan. Most of the nissans are now on timing chains. Altima, sentra, maxima, Z, armada, Titan, Pathfinder.

my 98 Corolla has a chain... or at least that's what I remember

Anything with the vg33 V6 has a belt. This includes Frontiers and Xterras as well as a lot of Pathfinders and Quests.

VQ35* ;)

the SR20DE has always used a timing chain.

mine's a 93.

there's a little bit of confusion on here.

yes the car has a timing chain, just like the camry. it is a zero clearance valve system so if the chain breaks the pistons will not smash the heads. the car will not run, but it won't have any new problems because of the chain snap'age.

there's a little bit of confusion on here.

yes the car has a timing chain, just like the camry. it is a zero clearance valve system so if the chain breaks the pistons will not smash the heads. the car will not run, but it won't have any new problems because of the chain snap'age.

Thanks for the "clear up".
Yeah, I was always told that, no matter what, if it was an OHC system of any kind, it would bend the valves if you snapped the chain/belt.
But technology is getting better and better...

tC come's with a BELT man

nope. the 2AZ-FE uses a single-row timing chain

everyone posting got me thinking so i contacted scion.. and they wrote this back about the tC's engine..

Thank you for contacting Scion.

It is through communications such as yours that we become aware of the
reactions and expectations of our customers and we appreciate your
inquiry. The tC engine is an interference design.


Please feel free to contact us should you have any further questions or
comments. We would be happy to assist you. You may contact us
directly at 1-866-70-SCION or by email at
https://secure.scion.com/scion/ssl/contact/contactForm.do

You may also want to click on the following link for
https://secure.scion.com/scion/ssl/contact/handraiserForm.do

Thank you for your interest in Scion.

Scion Customer Experience

Thank you for contacting Scion.

The tC engine is an interference design.




WHAT THE ( fill in the blank ) ??!?!

well, at least its a chain, but LAMENESS on the engine destruct design.

now we get to wonder which person on this thread is giving the CORreCt info.

bah

yeah i know.. i wrote scion and asked them and that's what they responded with.. i plan on double checking later on.. but i think that's crazy.. a chain so you never know when it needs replacing, like a belt that has a mileage requirement.. so bam it breaks.. bye bye engine! bad idea i tell ya..

but i am going to check some more with scion..

that doesn't make a whole bunch of sense, considering the camry is a non-interference engine. i know they squeezed 3 extra HP out of it (whoopeee) but i don't think those 3 hp would be coming from a a different internal design.

Guys stop thinking about it braking, it wont, and if it does, im pretty sure it will be cover by toyota even if you have 100.000 miles just bacause there suppose to pretty much outlast the engine itself, also for the person that said that all SR20DE have chains that is not true, only the newer DE's have the chains

When was the last time you saw a timing chain break? I've never seen one break on a street engine, and I did my first engine rebuild in 1973. Belts are typically non-interference because belts break. Not all belts are equal, and not all belt driven cams are on non-interference engines. I made a lot of money on '84 - '86 Ford Escorts because they typically broke their timing belts at 55k miles, just after the recommended 50k mile replacement. Some got away cheap, some needed complete engines.

Toyco uses belt driven cams on LOTS of their DOHC engines(2JZ, 3S, 4AG, etc.), and even some of the older SOHC engines. Belts are better for shock absorbtion, and crankshafts have a shock inducing event every time a cylinder fires. Score one for belts. Chains last forever. They run in an oil bath (as long as you follow the recommended change intervals), and it is nearly impossible to break them. However, they do wear out, and as they do, cam timing retards. Score one for chains. Neither is a big deal for a street car.

So, what do you want? A very high performance engine (close tolerance, interference design, with a chain that will outlast the car) or a $150 repair bill for changing the belt every 60k miles?

The cheapest modern Toyota that has timing chain is the Echo.

Yeah, $150 repair bill, plus some Technician opening up the engine and missing around with it. :)

thats sweet news Epstein,
I cant belive what a bang for the buck this car is.





nice job TOYOTA, errrrr Scion



oh and for 2 points, is it a non seize engine to boot? PLEASE Help me hehe

It doesnt matter if it is a chain or belt to be an "interference engine"
its all about it having the overhead cam, so yes, it will mess the valves up if it snaps/breaks...as far as I know at least...

Not all over head cam engines are interference. The clearence between the valves and the pistons is not dependent on whether the cam is overhead or not. Many overhead cam engines are non-interference.

When I bought my TC the guy at the dealer said the TC has a timing chain and its good for 500,000 miles, so stop worrying ;)

since 2002 all 4 cylinder toyota's have been timing chains, all v6's and v8's except the 4.0L v6 are belts.

The xC was scratched because volvo already had rights on it.

Here is a quote from the Road & Track test drive:

"Why not xC, you ask? Well, Volvo has the rights to that with its XC90. The tC stands for Touring Coupe"
http://www.roadandtrack.com/article.asp?section_id=3&article_id=1823&page_number=1

I know that doesn't answer the "timing chain" question but interesting anyway.

Guys,

I've had plenty of timing chain engines. I've never seen one just 'let go'. unlike a timing belt. A Timing chain will start to make a lot of noise too before it ever even gets near breaking. So if it starts making noise you have plenty of time, don't ignore it but also know that it won't just let go right away.

One thing though - since you have a timing chain - changing the oil is crucial since the engine has oil squirters shooting oil at the chain to heep it nicely lubed.

My old 18RG Toyota engine uses double row timing chain. It just goes and goes.

Thats true, properly cared for, a chain will usually last close to the life of an engine. Belts IMO are junk. Not only is the replacement interval way shorter than a chain, they have the tendency to simply snap when they wear out with no warning signs.. then you can say bye-bye to an interference engine.

jeez, my buddy's 95 grand am has a timing chain. belts are oldschool nowadays...except for with ferraris or something

jeez, my buddy's 95 grand am has a timing chain. belts are oldschool nowadays...except for with ferraris or something

Actually, belts are WAY newer than chains.. they are just losing popularity due to the short service intervals. They were a neat idea for dampening some vibration, but just do not last long enough. And last I looked Ferrari is still using chains.

sr20det's out of jdm silvia's have timing chains, as do all ka24de's (all 240sx, early altima, hardbody pick up).

the vast majority of people running 15 year old 240sx's still have their original timing chains. a small number do replace them for piece of mind. the tensioner is what needs to be replaced periodically.

Wow, we really reached back into the vault for this one didn't we? Before today, the last post in this thread was February 5th! Almost 5 months ago!

interesting... thats funni how they said that

I have yet to hear of a truly non-interference engine. Show me.

Nothing wrong with belts, you just have to maintain them and replace them when you're supposed to. Just like tires or oil, if you don't, you will have problems.

Thank you for contacting Scion.

The tC engine is an interference design.




WHAT THE ( fill in the blank ) ??!?!

well, at least its a chain, but LAMENESS on the engine destruct design.

now we get to wonder which person on this thread is giving the CORreCt info.

bah

I just asked three guys at me dealer they all told me, The tC engine is an interference design.

I have yet to hear of a truly non-interference engine. Show me.

Nothing wrong with belts, you just have to maintain them and replace them when you're supposed to. Just like tires or oil, if you don't, you will have problems.

What do you mean by "truly" interference? Ford built plenty of them.

What no one has ever mentioned in this thread is how retarted it would sound to name a car the "Scion Timing Chain" :rofl: :rofl: :rofl: :rofl:

Next, it will be the Saturn "Electronic EGR Valve" , or the "Chevy Oil Pump", or even the "Toyota PCV Valve" :P :rofl: :rofl: :rofl: :rofl:

Not making fun of the original poster... it just hit me how funny that sounded.

I have yet to hear of a truly non-interference engine. Show me.

Nothing wrong with belts, you just have to maintain them and replace them when you're supposed to. Just like tires or oil, if you don't, you will have problems.

What do you mean by "truly" interference? Ford built plenty of them.

Like?

I have yet to hear of a truly non-interference engine. Show me.

Nothing wrong with belts, you just have to maintain them and replace them when you're supposed to. Just like tires or oil, if you don't, you will have problems.

What do you mean by "truly" interference? Ford built plenty of them.

Like?

Many of the 2.3L, 1.9L, 2.0L and 3.2L Fords are non-interference. I have personally seen 4 2.3L fords break timing belts running down the highway. Replace the belt and go down the road.

I have yet to hear of a truly non-interference engine. Show me.

Nothing wrong with belts, you just have to maintain them and replace them when you're supposed to. Just like tires or oil, if you don't, you will have problems.

What do you mean by "truly" interference? Ford built plenty of them.

Like?

Many of the 2.3L, 1.9L, 2.0L and 3.2L Fords are non-interference. I have personally seen 4 2.3L fords break timing belts running down the highway. Replace the belt and go down the road.

So what motors are these? OHC? Years and Models?

Anything with the vg33 V6 has a belt. This includes Frontiers and Xterras as well as a lot of Pathfinders and Quests.

VQ35* ;)


its 3.3 liters, i own a frontier.

The ones mentioned are ohc. I dont have specific year models, but most year models of the ones listed were non-interference if I recall correctly. I know the 1997 escort version of the 2.0 was actually interference, but the rest are non-interference. The 2.3L that was used in the mustang until they went v6 was also non-interference, as were the 2.3s in the ford rangers. As I mentioned before, OHC does not mean interference or non-interference. The same engine in different forms can be one or the other depending on the head design. But a non-interference engine is not exactly a rare thing. Toyota, GM and many other companies I am sure have made both interference and non-interference engines. I believe your car is interference in design. I'm not trying to get into an in depth argument. Just passing along info. But for now I am going outside to have some rum. :P

I know OHC doesn't mean non-interference. What I was asking for was proof of an OHC non-interference engine.

The ones I listed are. I am sure there are plenty of others if I looked around. Those are just ones I was more familiar with. Like I said, I have seen the 2.3L break a few times without any damage, all 4 at highway speeds. They tended to break around 5k past the reccomended service interval.. the manufacturer really allowed for some design overhead on that one huh :P If ford says replace at 50k... do it, they dont leave much room for error!

Just as some people thought your Scion engine was non-interference until someone emailed Toyota.

Like I said, not going offtopic or starting an argument, I just haven't found one yet.

Just as some people thought your Scion engine was non-interference until someone emailed Toyota.

Like I said, not going offtopic or starting an argument, I just haven't found one yet.

I dont think these were, I was the one that replace the belts and got them going again (worked at my fathers shop here and there while growing up, so I have encountered many different engines). I also owned an 89 mustang with the 2.3L and completely tore down the motor and rebuilt it. Many of those I listed I remember from either working on or from the service manuals. The speculations about the tC engine were only that, speculation. I have no idea to be honest about the 2az-fe because all I have heard was heresay, which I refrain from repeating. Like I said, it is hardly a rare occurence to find one, they are out there.

Just as some people thought your Scion engine was non-interference until someone emailed Toyota.

Like I said, not going offtopic or starting an argument, I just haven't found one yet.

I broke the belt in a 1986 MR2 4A-GE at 80 mph. The car coasted to stop. I tried to restart it for a moment but figured out pretty quickly when the tach went to zero at speed that the timing belt broke. I bought a belt, tensioner pulley, lower gear, and tensioner spring. I installed them the next day, started the engine and it ran as if nothing had happened. That NEVER happened with an '84 to '86 Escort. Every one of them bent the valves because the pistons hit the valves in the cylinder with open valves. One time it even cracked the exhaust port at the valve guide and leaked coolant. The owner had to buy a new head. I've never had that happen with a belt driven cam on a Toyota.

Oh, engifineer, belts can make more power than chains. No timing scatter because the cams are not being jerked back and forth with every power pulse on the crank. If your distributor is cam driven (as many are) it also reduces ignition timing scatter. Both of these things mean you can make more power with a belt than you can with a chain or gears. It isn't always true, F1 are using chains these days, but I bet it's for a different reasons, and their stuff is pretty bizarre anyway. I can't remember the last time I saw a street engine with a 20k rpm redline.

As far as the cams.. there can be a tiny difference in power with the belt... I have not seen huge differences in the numbers. But a chain setup is typically better for a performance engine in every case I have seen. They are more durable and can withstand more punishment over time than a belt. At least with the setups I have seen.

As far as the distributor that is true.. but you wont be finding a distributor in many cars these days :P Our cars run a fully electronic ignition with a solid state ignition module.

Hopefully we won't be seeing cams much longer either. International already has over-the-road trucks running camless engines. It's only a matter of time now until we have ideal cam timing at all loads and rpm.

Ok, I'm going with a straight gear to gear (sounds like a supercharger) setup because I'm tired of all this :D

Let it die.

yeah, a few of my buddies' mustangs have gear-drives. most acurate timing, I guess.