Hmm my water pump failed again!!!! Could it be the pulley?!?!

[YarisSedan]

Okay so i went out this morning to check the tightness of the belt. When i installed the pulley before i marked the position of the altenator with white out. So the tightness of the belt is the same as the factory installed when i was done. So assume from factory it was isntalled with the correct tightness that would not be the culprit of the original water pump failure.

I have put on about 1k miles since it was repaired previousely after the just put in a new water pump and failed again. This time i look at it the mark i made is still there and it is tighter than what is marked. I did the pinch test and the belt is pretty tight. Not insanely tight but is tighter than it should. So i would attribute the undamped pulley compounded with the overtightend belt causing it to fail much more rapidly this time.

To me that can be the only explination. I have a feeling if the factory pulley was ont he even with a overtightend belt it woudlnt have failed at 1k miles. But more like 50k or later.

I do know overtightend belts cause things such as bearings to faull preamaturely but not at only 1 month after it has been done. Unless superman was doing work on the car and there was no belt deflection at all then even then within amonth still seems kinda fast.

[Altitude]

Do you know if your replacement pump was new or refurbished?

[severous01]

is there anything on a EWP? electrics are very reliable, and dont leak nearly as much. and with modern electronix, they last a lot longer. mezerie has one that's boasting 40k hours before it fails. that's like 500k miles unless you're idling all the time. even then if it's tied into the fan relay it'll only come on with the fans.

any way, we got elec power steering, why not water pump?

[lilredrocket]

Garm has an EWP on his setup

[curik]

I'm also looking to get a EWP kit, I posted the details here http://www.yarisworld.com/forums/sho...t=22604&page=2

[ROCKLAND TOYOTA]

LOL at the all the different excuses as to WHY. ive got 18,500 redlined miles on my pulley and OEM water pump which was installed by a toyota tech.

FYI, ive had more than a few STOCK yari come in here needing a water pump and TOYOTA is aware of a problem which is not to say that OVERTIGHTENING isn't a problem either......

[Tamago]

regardless if "improper installation" or the pulley itself caused the failure, the mere fact that you "fixed" something that wasn't broken in the first place (which in itself broke) is the deciding factor.

18 year old kids are most likely to die sooner if they ride motorcycles

but does that mean that the motorcycle is to blame?

no.

see what i'm talkin about?

[YarisSedan]

Yeah I get what your saying. Either way i think i am going to put the factory pulley back on atleast for the time being. I am giong to try to bring my car in on my day off this week. I know more than likely since they just changed it they are going to look for a reason as why it just failed. And the mechanic wont want to take responsibility. They didnt notice the pulley last time or atleast didnt note it down. I think cause i got the greish colored one not a bright red one. But if i bring it in again and leave that on they are going to not warrenty it again.

Even if i try to take it to another toyota dealership they will be able to check national database for submitted warrentys for this car i would assume. So better safe than sorry.

[NonStopTuning]

I'm sorry to hear about your troubles YarisSedan, and I am glad to hear that you are trying to find a logical reason and solution for your problem. It is often easier to point the finger at an aftermarket item than try to find the real problem and solution.

We have literally sold THOUSANDS of crank, alternator, and water pump pulleys. I think it is a testament to the quality of our product when I say that 99.99% of our customers have never had any water pump (or any other) problems to speak of. This includes Toyota, Scion, Lotus, Honda, Nissan, VW, etc.

As ROCKLAND TOYOTA stated, I have also heard of a couple of local Yarii going in for service with their stock pulleys. To add to this, I have also heard of some of the new Civics and Scions, having similar problems. All of the cars I have seen locally with this issue have had the problem covered under warranty... which should tell you something in, and of, itself.

Again, I am sincerely sorry to hear about your troubles, but I don't think everyone else should go into a state of panic over a few isolated incidents... especially when there have been hundreds if not thousands of positive reviews the other way.

Thanks again, good luck and have fun with all your projects!

[Tamago]

i'm not saying you don't build quality (in this case, really, "within tolerance" parts) my statement is pointed toward what we call bleeding edge parts. bleeding edge performance parts that are installed BEFORE other mods tend to cause issues, simply because the owner is not on the same mental level as the typical bleeding edge driver. for instance, lexan windows in an otherwise stock (yes lol, this is going on right now as we speak, here on yarisworld) yaris is simply stupid. a person doing bleeding edge mods such as aftermarket lightweight pullies, to eek out as much power as possible, should be willing to accept and compensate for damages caused by said product, due to extra shock on the pulley system itself, caused by the lack of dampening.

[NonStopTuning]

Disclosing our great success rate with over 100 different pulleys for Hondas, Nissans, Toyotas, Lotus, Scion, VW, etc. should tell you quite a bit about our past and our products.

If you look through the different forums where our products are popular, you will find thousands of customer reviews, all of which have been positive. Further, you will find discussions like the one I am going to copy and paste for you here....


This one deserves an entire book, but here goes...

Q. Will NST Pulleys lead to premature engine failure?

I cover this topic at least several times a month but I don't mind, I understand that your cars are a very large investment for all of you and I prefer that you be intelligent and informed about all your modifications. So here we go again... Please take a few minutes to read everything I have posted here, as I worked hard on trying to give you a good explanation on the topic...

In the past many engines were externally balanced. There was an external balancer attached to the outside of the engine, on the crank snout, used to balance the engine externally. The crank pulley in such engines would then be attached to this balancer. Removal of this balancer is a bad idea. These balancers were most often used on large (6 to V shaped engines of the domestic muscle car era.

Take a look at any modern (1980s and beyond) Honda, Toyota, Nissan, or other japanese inline 4 and you will find no such balancer. These engines are all internally balanced, and this process has improved even further since the late 1990s. So the topic of a BALANCER does not apply here.

What you will find on many modern engines is a harmonic damper. This is a small rubber band, litterally less than 2mm, less than 1/8th of an inch, thick that is built into the crank pulley. OEM crank pulleys are often called DAMPERS. Try placing an order for a crank pulley at your dealer and your invoice will read damper. This rubber is used to absorb something called NVH, noise/vibration/harshness. Suffice it to say, this rubber is actually not very good at performing its intended purpose after as little as a few thousand miles. What happens to rubber after a couple years of humidity, weather, snow, rain, etc? It often becomes brittle, hard, and crunchy. Can something with these properties actually absorb vibrations very well?

Many many NST customers, including people on your own forums, have reported smoother running engines with NST pulleys. Especially at idle. How is this possible if the rubber is such a vital and super important piece??? Perhaps the rubber is not as important as it is cracked up to be???


Furthermore....


On the topic of the rubber damper, engine vibrations, or possible threats resulting from elimination of this rubber piece...

On a relatively understressed near stock motor with bolt ons or low amounts of boost like what most of the people on this forum probably run, a solid pulley will not have any life threatening consiquences. The factory pulley with a 2mm (less than a 1/8th inch) damper is primarily there for wide band NVH (noise vibration harshness) supression from the engine and driveline. Removing the damper and replacing it with a solid pulley may lead to minor addtional NVH but will not harm the engine. In fact, most people claim their engines seem to run smoother with NST pulleys.

The engineering reasons are that most modern engines have a short, strong crank with, a relatively high natural frequency. The dangerous second harmonic that can cause damage occurs at an rpm that this sort of engine will never see, in the area above 10,000 rpm. Even the stock damper is not tuned for attinuation at this sort of rpm so the argument is somewhat of a moot point.

Now weak engines that are pushing the limit with LOTS of revs, wimpy cranks, super long strokes, lots of boost and dwelling in the upper rpm ranges for long periods of time can benefit from a damper designed to deal with this sort of operation but our engine is not like this, and probably very few people with this motor on this forum push the envelope that hard. How many 2.0 Liter, 500HP, 12,000RPM motors do we have on these forums?

As far as I can tell, our engine has a strong and stiff bottom end that is well built for our intended use. It has an internaly balanced crankshaft which is less like to break due to torsional vibration.

There are a lot of Honda, Toyota, and Nissan guys who use underdrive crank pulleys in road racing series like NASA or SCCA. Road racing is much more punishing on an engine than other motorsports. The engine is subjected to run times lasting roughly 30 minutes with the engine always in the upper ranges of its rpm limit. One race weekend is the equivlent of hundreds of 1/4 mile passes. These guys would not use NST pulleys if they were not reliable.

NST sponsors the first ever wheel to wheel Scion tC NASA Road Race car. The same car is also very competitive in the Grand Am series and has factory backing from Toyota, Scion, and TRD. This car has been using pulleys from NST with great results since day one.

NST has sponsored several drift cars participating in the professional drift series, Fromula Drift, and the D1 Grand Prix USA. Several of our cars have also competed in the NOPI and Pro AM Drift series. To make things better, NST products are also used in autocross, time attack, and drag cars. These cars have been using NST pulleys with no issues of any kind for the past few seasons.

We could go on and on...

Is a solid crank pulley harmless to all engines? No it is not. As I said... small, super high reving engines, when modified way past the simple bolt on stages may have problems. These engines reach critcal harmonics, past the 10,000 rpm range, an rpm only reached by certain RACE engines.

A mildly modded inline six will most likely be fine but one subjected to high rpm (7500) for long periods of time (90% of its life) with lots of boost (500+hp) will probably suffer. In this case , the stock pulley/damper is probably not adequate either.

Some of the older american V8 engines are externaly balanced and it is critical not to use a solid hub pulley not designed for these applications, or damage to the engine could result. You will not find solid NST pulleys on our website for such engines.

Our engines and most around here do not fall into the above catagories. Rest assured that your engines will not blow up and die or have a reduced life in street and even racing use with these parts.

I would bet that every "expert" that tells you otherwise has little personal, practical, real world experience with the subject; as it applies in your case.

Again, I understand that your cars are a very large investment and that you depend on them as your daily means of transportation, so I do not take your questions personally. But please... do a search through the links I have provided for you and you will find nothing but positive feedback from realworld customers.

Good luck and have fun with all your projects!

[mikenacarato]

for the record...i have been on quite a few road courses with my yaris and i do drive the crap out of it...i also drive the car daily and drive it hard...i have over 25000 miles on my nst pulleys and they have yet to cause an issue. my guess is someone didnt tension the belt properly and overtensioned it.

[hatchbackkid82]

no problems here.

[cali yaris]

if aftermarket pulleys were a 100% win/win situation, we would have lightened pulleys stock.

No, this logic is faulty. That would make the car more expensive. Like including a center console and so many other features we like so much on the cars.

Isn't a center console a win/win? But it's not on there, is it? Lots of parts that would improve the car in various ways aren't on there.

They designed and built a $12000 car.

[ozmdd]

Garm is correct -lots of stuff on the Yaris that isn't produced at the highest-possible engineering or efficiency. Its almost always a cost-benefit relationship, with the "benefit" portion being biased towards the level of performance that will please the average consumer.

Take the rear sway bar - the car was designed to have one, but is produced without one to save $$. It's almost inarguable that the rear sway is a win-win item.

I think a lot of folks here ought to have more knowledge/facts before they knock a product that clearly has a lot of R&D behind it, especially a small company that is trying to produce small-batch products for a market that isn't catered-to by very many manufacturers.
Speculating that the NST pulleys cause or contribute to water pump failure is damaging to the company's reputation, even when there is no direct evidence to support that speculation.
If you don't KNOW something, don't comment as if you do. Good engineers don't link cause-and-effect to anecdotal relationships, like many of the nay-sayers have done on this issue.

[supmet]

Originally Posted by cali yaris

No, this logic is faulty. That would make the car more expensive. Like including a center console and so many other features we like so much on the cars.

Isn't a center console a win/win? But it's not on there, is it? Lots of parts that would improve the car in various ways aren't on there.

They designed and built a $12000 car.

Originally Posted by camelll

NST said that the damper is for NVH for the driver and to eliminate cabin noise! Toyota was not thinking about cabin noise on a 12,000 dollar vehicle, show me anywhere else on the car the were concerned with cabin noise.

Please explain to me how making a solid crank pulley is more expensive than making a 2 piece? Even NST will attest that a 2 piece is more expensive to make.

camelll's two points pretty much show where my logic was going, and I don't think its faulty.

Whatever though, I don't think there is enough evidence to say one way or the other. I'm just a little tired of everyone on the forum saying 99% of mods do no damage to cars, and even if they do, the magnusson moss act will be there to protect you.

Everyone I've talked to in real life with modded cars has a completely opposite philosophy, which is you gotta pay to play. That philosophy seems a lot more inline with the way the rest of the world works. Nothing is free. Your car was engineered for stock parts, and that's it. Any aftermarket part has risks involved, and I feel there is more than a little smoke being blown around here.

[advocate]

The way I see it is this: The percentage of people who are on YarisWorld is a very small percentage of actual yaris owners. If there's bad water pumps in a significant amount of yarii, then the percentage of all yarii with bad water pumps on yarisworld will reflect the percentage of all total yarii with bad water pumps as well.

This fact alone doesn't mean much but there's also something very important to consider and that's that your average YarisWorld member is much much more likely to have aftermarket products installed and be aware of their engine's health than the average Yaris owner.

Since the pulley is such a popular mod, and modders are likely to post about when their water pump fails, this might lead one to think that the pulleys are what is causing the water pump to fail.

In the end it's all about perception. In this thread alone we don't have good representation of all of the Yarii out there who have had bad water pumps without mods. All we see are people with average to lots of mods, many of those use the NST pulley, and all of them have a very high chance of posting about their pump when it fails giving the overall impression that the pulley must be causing the pump to fail.

As far as my personal opinion goes I can't say one way or the other because I don't know anything about cars and I don't have the light weight pulleys installed but I do know about statistics and this is certainly a case where it's important to remember how much of a small fraction of the population this is: Yarii owners -> Yarii owners on YarisWorld -> Yarii owners on YarisWorld with mods -> Yarii owners on YarisWorld with mods and the pulley installed.

Just to reiterate: I'm not saying the pulley won't sometimes break, or never will contribute to a water pump break. I'm just trying to point out that when drawing generalized conclusions it's important to take into consideration whether or not the cases you're drawing your conclusion from represent an accurate average of ALL THE TOTAL cases. Mike @ NST is arguing that these isolated cases don't in fact reflect the true average or experience of all the total people who use NST pulleys and I'm inclined to agree.

[Astroman]

A great post but... what does the harmonic balancer and a failed water pump after a month have to do with one another? The most likely culprit is a defective water pump or improper installation.