Timing Belt Change Interval 2009 Jetta

Sharpie

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2001
Bought my new '09 Jetta today. Traded the '01 Bug TDI in. The dealer said the timing belt change interval is now 120,000 miles. What did they do to get the interval up from 60 - 80k that I had on the bug?
 

btcost

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better belt. less stress (no IP to drive)
 

All of Us

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Don't the CR cars have an IP? If not, how do they pressurise the fuel to the "bazillion" PSI figures I've seen quoted in the info about VW's common rail system.

Dan
 

btcost

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they do. but it is not driven by the timing belt.
 

Mike46

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NONE yet
Swore I'd never buy a VW again

After neglecting a recommended timing belt change (to cheap) on my wifes '05 passat, I was taught a lesson. The belt went about 10k miles after rec.change date and f_ _ _ _ d up the car engine so bad that it would cost more to fix than the value of the car. I swore I'd never buy another VW again (teach them a lesson for MY stupidity). We'll I'm eyeing the new JSW tdi's and due to value for the $ and milage, will be getting one. Lesson learned.
 

El Dobro

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The high pressure pump is driven by the timing belt.
 

btcost

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I was not 100% sure.

I do believe that it puts less stress on the t-belt than the ALH and other style pumps.




El Dobro said:
The high pressure pump is driven by the timing belt.
 

dr61

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I could be wrong, but after looking at engine pictures posted elsewhere, it appears that the timing belt on the 09's also does not run a power steering pump (electric), the second camshaft, or the balance shafts (run by gears off of one cam).
 

oilhammer

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outside St Louis, MO
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There are just too many to list....
The CBEA engine has an entirely different head and injection system than previous engines. And common rail injectors actually DO give the fuel that last punch of pressure needed for diesel injection, the high pressure pump merely "pre-pressurizes" it. While the CBEA does have twice the camshafts and valves, they are much smaller so the overall spring pressure is likely not any different.

Also, the belt itself may be chunkier or of a revised material, but either way it is a totally different head.
 

DPM

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oilhammer said:
And common rail injectors actually DO give the fuel that last punch of pressure needed for diesel injection, the high pressure pump merely "pre-pressurizes" it.
Uh, you wanna explain that one, OH?
 

oilhammer

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There are just too many to list....
Actually, I guess that is not really clear, sorry. The piezoelectric type injectors developed have a lower chamber that holds a certain quantity of fuel (I have some great pics in a Bosch book at work). They are not quite the same as a gas injector that simply opens up a hole by pulling a needle up, the diesel injectors use that lower chamber full of fuel to allow the needle to pull up which allows the use of greater pressures. Then the actual delivery can be stepped or staggered over a longer duration, with much tighter controls. Not a huge single 'WHAM' of fuel with a very sharp taper of delivery. Without them, the injection pressures could not be as high as they are and still be controlled so finely. PDs actually have very high pressures as well, but cannot be controlled as well, thus they still have the signature diesel clatter the CR does not. The CR's injectors allow some method of 'amplification' of the delivery pressures, that is the best way I can describe it.

Here is the best pic I can find:

http://www.blogcdn.com/www.autobloggreen.com/media/2008/09/dfi3.png

So no, the injectors are not "injecting" the fuel, I apologize for that statement, that was not what I meant. I just meant to say that there is much more to them than a gas engine's port injector which is simply an on-off solenoid that is controlling a pintle that is either open or closed.

So the load on the belt does not have the violent jerks and such that the previous systems (especially the PD) did. The load is more constant and linear. The load on the PDs is so great the teeth on the crank sprocket are actually not spaced or shaped the same all the way around, but are ever so slightly different to counteract the extreme pulsing of the belt drive system. If VAG can make the PD's belt drive work (and they do, have not seen one fail yet) then the CR is easy. ;)
 
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Matthew_S

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I think (not sure though) that the CBEA uses the new belt design from Conti/INA that has an oval sprocket to smooth out the pulsing load on the belt. It was supposed to be considered "lifetime" in some applications.
 

Jack Frost

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It seems to me that I read that these piezo injectors are crystals that shrink or expand when a voltage is applied to them. This in turns opens up the orifice that atomizes the fuel. I believe this is the same principle used in phonographic needles only in reverse.

This relieves an engineer of designing mechanical shafts and pumps to time the injection event leaving it all to the software designer instead who is not limited to as many mechanical realities such as the force and power required to drive all the mechanical components the older injector technologies had.

It is too bad that the same computer also runs all the other anti-pollution technologies that undo much of the mileage and efficiency gained.
 

oilhammer

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There are just too many to list....
Actually, the mileage and efficiency stayed pretty close to the same, they just blew the new technology on making the engine more powerful and cleaner. If they would have kept the output at about 100hp, but used the new CR setup, we'd have 65 MPG Jettas.
 
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