# Noob question: is the 2.0 an interference engine?



## Darter (Aug 24, 2002)

The salesman, just before purchase, tried to convince me it is a non-interference engine. Quote "This is the 8 valve 2.0, not the 16, so it's a non-interference engine." I didn't go for it, since I thought 99.9% of all foreign engines are interference engines.
Also, was there really more than one variety of 2.0 engine in '97? I'm guessing this guy was just telling me whatever he could to sell the car. My sis-in-law bought it, regardless of the engine type, but I want to know how urgent it is to change the timing belt at 82,000 miles.
The salesman claims it was changed at 60K, but the service records will tell us that once we get them.


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## ashleync (May 28, 2002)

*Re: Noob question: is the 2.0 an interference engine? (Darter)*

I'll give you a bump for a good question that is almost identical to mine...
2000 Model with 86,200 on it. Don't know if the belts have been changed, and don't want to take the chance...


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## Pagano (Sep 24, 2001)

*Re: Noob question: is the 2.0 an interference engine? (ashleync)*

I'd also like to see an answer to this question as it usually goes back and forth and then dies
Can anyone confirm
OBD1 or OBD2, is there a difference, or are they the same in terms of interference


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## breaker (May 29, 2000)

*Re: Noob question: is the 2.0 an interference engine? (Pagano)*

I remember a couple of years ago this was discussed and the answer was an unequivocal "Non-interference." 
Lately its been discussed and the answer's been "Absolutely an interference engine." 
So... Darned if I know.


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## timmybgood (Dec 12, 2001)

*Re: Noob question: is the 2.0 an interference engine? (breaker)*

i've never even heard of this


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## VDUBDRIVER (May 28, 2000)

*Re: Noob question: is the 2.0 an interference engine? (timmybgood)*

the 2.0 8V engine is a non-interference engine...no damage will occur if the timing belt breaks...no worries...
16V, TDI 1.8T are interference engine...valves and piston tops will be damaged if the belts break...new head and piston will be required...thousands of dollars in damage...very bad...
VR6 is interference but has a chain...unless you have very high mileage you should have no problem...
Later, VDUBDRIVER


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## JettaRed (Aug 14, 2000)

*Re: Noob question: is the 2.0 an interference engine? (VDUBDRIVER)*

Actually, the 2.0 *IS* an interference engine. You can look it up yourself from this Gates Belts Timing Belt Guide: http://www.gates.com/downloads/download_common.cfm?file=GatesTBR.pdf&folder=brochure
You'll find both the ABA and AEG engines are interference engines. Of course, if you don't believe them, remove the belt and crank the engine and let us know what happens.


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## Bob Roberts (Aug 13, 2000)

*Re: Noob question: is the 2.0 an interference engine? (VDUBDRIVER)*

quote:[HR][/HR]the 2.0 8V engine is a non-interference engine...no damage will occur if the timing belt breaks...no worries...[HR][/HR]​








Are you going to pay for the head damage when the belt goes?!


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## SILVERADO (May 16, 2002)

*Re: Noob question: is the 2.0 an interference engine? (Bob Roberts)*

This is a much misunderstood topic with these cars.The experience I have working on VW engines over the years has tought me this.These engines,for the most part are both.I have personally seen and repaired 16v motors that have broke a belt at very low speed(pulling into a driveway,intersection,etc.)and I had replaced the belt,did a compression test,and NO damage,and I have experienced 16v motors that break on the freeway,over 2k rpm and BAM! intake and exhaust valves bent,and a $1500.00 repair bill.I have only seen a 2.0l 8v bend valves during high rpm freeway driving,the car bent 2 valves in two different cylinders.That is the only time I've seen 8v's bend valves is during high rpm operation and they were always manual transmission cars,the automatics don't rev as high and seem to be immune.So they CAN bend if your timing belt breaks,but USUALLY DON'T but I would'nt want to take a chance,replace every 45k-50k.


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## JettaRed (Aug 14, 2000)

*Re: Noob question: is the 2.0 an interference engine? (SILVERADO)*

Theoretically, engine rpm should not be a factor in whether an engine will be damaged unless it has variable valve timing (e.g., VTEC). However, real life experience may prove different. SILVERADO, do you have an explanation?


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## doctordon (Aug 25, 2001)

*Re: Noob question: is the 2.0 an interference engine? (VDUBDRIVER)*

quote:[HR][/HR]the 2.0 8V engine is a non-interference engine...no damage will occur if the timing belt breaks...no worries..[HR][/HR]​Wrong!!!! I've personally had two customers with 2.0's who waited too long to change timing belts and resulted in bent valves. I've also had others that didn't bend valves. Same with 16v, most bend valves, but sometimes luck happens!


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## doctordon (Aug 25, 2001)

*Re: Noob question: is the 2.0 an interference engine? (Darter)*

At 82k, you're living on borrowed time. I've seen belts strip as early as 52k. I've seen valves bend on two 2.0's. If you have 10/100 and the belt breaks, you're covered, but they will want a service history.


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## SILVERADO (May 16, 2002)

*Re: Noob question: is the 2.0 an interference engine? (Dr Don Madbug's Dad)*

Doctor Don,you know your sh*t,and have seen,like myself that some bend valves and some don't.However the funniest thing to me is that owners ,if they would just follow the recommended service intervals,would save thousands in needless repair!But owner negligence is why we still,and will always have a job.Do you agree?


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## Darter (Aug 24, 2002)

*Re: Noob question: is the 2.0 an interference engine? (Dr Don Madbug's Dad)*

Okay, so based on this discussion, I'm going to make the unofficial call that 8v 2.0 engines are in fact interference engines.
But I'd still like to hear about how engine speed affects level of damage in a non-variable valve engine like the 2.0. If the engine turns 2 revs, something just HAS to make contact somewhere, at any speed.


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## SILVERADO (May 16, 2002)

*Re: Noob question: is the 2.0 an interference engine? (Darter)*

momentum,inertia?Maybe that valve stays open a little bit longer at high rpm.


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## eurotechracing (Aug 20, 2000)

*Re: Noob question: is the 2.0 an interference engine? (SILVERADO)*

Just to chime (YES) they are interference motors.
Thanks Les


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## Bob Roberts (Aug 13, 2000)

*Re: Noob question: is the 2.0 an interference engine? (eurotechracing)*

quote:[HR][/HR]Just to chime (YES) they are interference motors.
Thanks Les[HR][/HR]​My god! A post where les isn't trying to sell or defend his product!


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## Red Baron Golf (Jul 18, 2000)

*Re: Noob question: is the 2.0 an interference engine? (Bob Roberts)*

quote:[HR][/HR]Just to chime (YES) they are interference motors.
Thanks Les
My god! A post where les isn't trying to sell or defend his product![HR][/HR]​LOL


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## brinskan (Jan 21, 2000)

*Re: Noob question: is the 2.0 an interference engine? (Red Baron Golf)*

* for all sake it is a interference motor.. by definition...* but no way like a 16v or 20v.... my car was running 90' out.... guess what no bent valves.... a 8v will start 180' out.... 8v only bend valves at HIGH rpm belt breakage. my boy works at vw, he gets snapped timing belts on 8vs all day long... its covered under powertrain warrenty so no one replces them when they should,,,,


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## spitpilot (Feb 14, 2000)

*Re: Noob question: is the 2.0 an interference engine? (brinskan)*

Bentley manual has warning "Do Not turn engine over with timing belt removed, internal engine damage" in the timing belt replacement section for the 2.0L engine, for what thats worth. Having spent 2+ hours by the freeway one evening trying to get a tow with my cell phone, I'd opt for changing the belt B4 it breaks, rather than going to the last mile! (My ECU crapped out, not the belt but the car still just sat there). What you save by stretching out replacement interval a few 1000 miles will pale in comparison to tow and potential engine damage costs!


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## blubayou (Oct 3, 2001)

*Re: Noob question: is the 2.0 an interference engine? (spitpilot)*

My g/f's timing belt broke on her 2.0L 8v at 70-75 mph and it was fine, not internal damage whatsoever. just some fuel for the fire


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## whiteboy1 (Nov 15, 2001)

*Re: Noob question: is the 2.0 an interference engine? (blubayou)*

How can i tell if the belt needs changing? I bought my 95 jetta with 86,xxx and it now has 97,xxx. I dont want to f it up so could anybody let me know how to check? Also, what kind of $ is involved in the change? thanks!


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## spitpilot (Feb 14, 2000)

*Re: Noob question: is the 2.0 an interference engine? (whiteboy1)*

Pull top belt cover (two clips) and look at belt. See any cracking, edges worn? If so its been on there since day one and you'd better change it out. DIY change about $50-75 for parts and 2 hours work. Dealer here wants $475 for the job! Im sure you can get it done cheaper,maybe $250-300 at independent shops.


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## bradleyland (Aug 25, 2002)

*Re: Noob question: is the 2.0 an interference engine? (spitpilot)*

The reason that speed and RPM play a factor in the amount of damage is that most timing belts dont break, they lose cogs and skip a tooth or two. If your timing belt actualy breaks, then I can't see RPM being to big a factor.


[Modified by bradleyland, 10:52 PM 8-30-2002]


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## GtiGyver (Mar 22, 2002)

*Re: Noob question: is the 2.0 an interference engine? (bradleyland)*

At high RPMs you will gain extra lift and duration from the momentum the valves, this is one of the reasons higher revving engines use stronger valve springs (you never want valve float). The 2.0 ABA is NOT an interference engine if it is being turned over manually, anything more than that and you might have valve/piston contact.
If you are on the highway (for example) revving 3000+rpm, its almost guaranteed for you to end up with bent valves unless you are really lucky.
But cranking your engine over by hand, should not be a problem.
BTW, this is ONLY applicable to stock cams, anything other than stock will definitely result in BIG repairs.
quote:[HR][/HR]If your timing belt actualy breaks, then I can't see RPM being to big a factor.[HR][/HR]​


[Modified by gti_8v, 12:26 AM 9-1-2002]


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## bradleyland (Aug 25, 2002)

*Re: Noob question: is the 2.0 an interference engine? (gti_8v)*

I hate to nitpick, and I've never turned a 2.0 over by hand, but your statement is somewhat contradictory.
quote:[HR][/HR]At high RPMs you will gain extra lift and duration from the momentum the valves[HR][/HR]​This is *exactly* what valve float is.
quote:[HR][/HR]this is one of the reasons higher revving engines use stronger valve springs (you never want valve float).[HR][/HR]​This is completely true, you never want valve float, and high reving engines do have stronger valve springs. 
By your statement, essentially all high reving engines experience a form of VTEC like valve overlap/duration extension. I simply don't think that's true.


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## doctordon (Aug 25, 2001)

*Re: Noob question: is the 2.0 an interference engine? (SILVERADO)*

fer sure! fer sure!


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## doctordon (Aug 25, 2001)

*Re: Noob question: is the 2.0 an interference engine? (gti_8v)*

quote:[HR][/HR]The 2.0 ABA is NOT an interference engine if it is being turned over manually, [HR][/HR]​I beg to differ. If you put the pistons at TDC, take the belt off and turn the cam, you CAN feel the interference. This also goes for the 1.8 engines.


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## DubLove (Jul 27, 2002)

*Re: Noob question: is the 2.0 an interference engine? (Dr Don Madbug's Dad)*

FELLA's, I didn't read the whole post, but I HAVE THE ANSWER, I found out the hard way a week ago, My timing belt Tensioner Seized, causing my Timing Belt to SNAP. I just finished putting in a REPLACEMENT motor, I have a 2.0L 8v Engine, MK3, OBD2.
So if this isn't enough of an answer, If anyone begs to differ, you can come to my house and look at the 3 bent valves in my head, it's all torn apart right now.
Bottom Line, the 2.0L IS AN INTERFERENCE ENGINE. 
BTW, I would recommend that ANYONE with a 2.0L replace your Timing belt and Tensioner EVERY 60K Miles, This $25 timing belt and $15 tensioner has cost me over $1500 this last week in damages. Wish I hadn't procrastinated now.


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## fundub (Feb 11, 2002)

*Re: Noob question: is the 2.0 an interference engine? (DubLove)*

DubLove - how many miles did the dub have when the belt broke ? Just out of curiousity.


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## David4516 (Sep 3, 2005)

Ok so I see that this thread is like 10 years old, but I have a quick question that I think is relevant. 

If you get the code for cam shaft position sensor, is it possible that your timing belt has either broken or lost teeth? 

I have a 2003 Golf that has the 2.0L engine. I got it used; it has 135,000 or so miles on it. I am thinking that the belt may be the original one (as in it's never been replaced). The car died while at idle in the parking lot, the check engine light came on, and when I checked the code it said it was the camshaft sensor. 

After reading this thread, my fear is that it might be worse than just the senor? Is that possible, or am I all worked up over nothing? Now I'm worried that my belt slipped or even snapped, and that I have damaged valves and everything.

I'm assuming that in the best case scenario, I should have the senor, the timing belt, and the water pump all replaced at the same time? How much should that cost?

OK I guess my one quick question turned into several questions. Sorry.

To make matters worse, after the golf died I started driving my old '78 Dasher. Planned on driving the Dasher until my tax return gets here and use that money to fix the golf. Well the Dasher died on me too. And the ironic thing is, I think it's the timing. It will start and run, but only if I hold down the gas a bit. If I let it idle, it just dies. When it does run, it feels like it has no power. I'm thinking that my timing belt just slipped a tooth? 

At first I thought maybe I just wasn't getting spark to one of the cylinders, so I changed out the distributor cap and rotor, spark plugs, and wires. Still not luck. Now I'm thinking that the timing is all goofed up, or that maybe I have a valve that is just stuck open or something?

So yeah I've had 2 VWs die on me in the span of a few days, and I think they both might have similar problems...


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## nabeelr (Jun 8, 2013)

*The definitive answer: From the Bentley Manual*

The answer depends on which 2.0. Some are interference, some aren't.

According to the Bentley Manual:

The AEG, AVH, AZG, and BEV 2.0L engines are interference, as the book says "Due to engine design, care must be used when turning camshaft with timing belt removed. If valves are allowed to open with piston at TDC, serious internal damage will occur."

There is no such warning on the BBW 2.0L engine.

This being said, it MAY still be an interference engine.



Edit: Turns out I was totally wrong about the above. Aparently all MkIV engines are interference.

The bently manual just doesn't give the same warnings about the other engines for some reason.


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## Butcher (Jan 31, 2001)

False. At speed, an automatic can run the engine, even with the engine off. 

The automatic needs a pump for it to work. The pump is driven off the converter which is driven off the engine. As long as there is pump pressure, the transmission will stay in gear. As long as it's in gear, the engine will spin. 

When the vehicle is stopped, you are not moving so the transmission cannot drive the engine.

In the end, when a timing belt breaks it's too late for you to do anything. You should have maintained the engine properly. It's bad decisions in life when that happens.


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## Butcher (Jan 31, 2001)

OMG you are so wrong.

YES, the is usually a one way clutch in first gear. Once you are out of first gear, then the one way clutch is no longer used. If you put the transmission in low, the one way is overridden with another clutch/band. This is to allow engine braking on decel. Useful on steep downhill roads.

I can say ALL the transmissions I have ever rebuilt/repaired, do not have a one way clutch except for 1st gear. My experience is with Mercedes and I've been to several factory schools and repaired hundreds if not thousands of Mercedes automatics. Top 10 mechanic in the country, Maybach and McLaren certified. I do know a bit about cars.

I've turned the key off of many cars and none of them caused the engine to die. Yes, if you go slow enough, it will. Yes, if you are in first gear is will. As long as the transmission pump is pumping, the transmission will keep everything working. 

One good thing, I will still be here and you will be leaving, fortunately for us, as fast as you came in.

Since I know you peeked at my post before you left, do yourself a favor. Get into an older vehicle. Drive at 60mph on the freeway. Find a gear that will keep the engine at 3k rpm. Shut off the engine. Then turn the key on again. Yeah, you will be very embarrassed because you will prove to yourself I'm right and you are mistaken. 

It is ok, I will accept your apology. No hard feelings.


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## Butcher (Jan 31, 2001)

I knew you were going to come back. 

Let's discuss. The converter is driven by the crank shaft. The pump is also driven by the converter. Since the converter is hard mounted to the crank AND the pump is hard mounted to the converter, if the crank turns, the pump turns. If that is not the case, then how can you put the transmission in drive if the pump is not working [with the engine running]?

If the pump is turning, then there is potential of it supplying enough flow for the transmission to work. If the pump is working, then it can supply the entire transmission with all the fluid flow it needs to keep clutches/bands engaged. If that is the case, when the engine power is off, the transmission can still keep the engine spinning because the pump is still engaged. The engine will spin slower than the transmission because of the converter internals. If you are at such a slow speed, it is possible that the engine will spins so slow that the pump [which is hard connected to the engine] will not supply enough flow to keep the clutches/bands engaged and at that time, everything stops working.

As you previously mentioned and you are correct, this would not apply if the one way clutch is used. Since this type of clutch is typically used only in first gear [so you can coast/no engine braking], the engine would not turn.

Remember, the pump is driven by the outside sheet metal of the converter, not the internal stator and what not.

I hope we can agree that if the transmission pump is supplying enough flow to keep a transmission in gear that it will stay in gear. If the output shaft of the transmission is engaged to the input shaft of the transmission [because that's what automatic transmissions do when in gear], then it is possible that if you coast at a fast enough speed that the output shaft would drive the input shaft, which would drive the engine. 

Of course, if the transmission is in neutral, the engine would stop running. If the transmission is using a one way clutch as a locking element, then that would most likely not keep the engine running.

In the end, we can both be civil and anyone that reads this can do it themselves. At freeway speeds, you can turn your key to position one, which would remove power to the ignition/fuel systems, wait a second or two, then turn the key to position #2. You will notice how the engine will still be running. How it can be running? Because if you slow down and think about what I said, it is possible and therefore I'm correct. 

With today's fancy electronics, it may be possible for some automatics not to keep the engine running but for the older cars, the engine can stay moving. 

It's ok that we do not agree. A forum like this is to share ideas and thoughts. It's ok to call someone out if you disagree with them or if they are wrong. Why people in America get upset because someone has a different opinion is something I have yet to understand. Why people disrespect other opinions is beyond me. If you cannot play well with others and like calling people names because they are different or have different opinions, maybe a forum is something you should stay away from.


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## Butcher (Jan 31, 2001)

FYI, Mercedes did put a secondary transmission pump in their 722.3 and 722.4 transmission so you could pull start the engine. Yes, you had to go 40mph or more for this to happen but it does work. The pump is operated on the output shaft and is disconnected when the primary pump provides enough pressure.


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## Butcher (Jan 31, 2001)

One other thing I thought about. Something you should ponder before you think about what words you are going to use to describe my intelligence,

Let's say you are going at 100 mph on the freeway. The engine is pushing, lets say 4,000 rpm. When you get off the throttle, what would the engine speed be? I think we would both agree, unless it has a locking converter, it would be slightly lower that 4k and would be decreasing in speed as you were slowing down. Do you agree with that? I hope so because this is where it gets a bit complicated.

Do you know that the fuel injectors are shut off during decel at higher RPM's? If not, you should because all engines are this way to reduce exhaust emissions. So, if the injectors are off, I hope we can agree that, the engine probably would not run. If the engine is not running, because the injectors are shut off, then how does the engine keep turning and not completely stop?

Remember, keep calm and come up with a good response with less colorful words to describe my intelligence.

Class is over.


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## Butcher (Jan 31, 2001)

You've said that before but like the other responses, you have side stepped the facts.

Injectors shut off on decel and with automatic transmissions, none of the cars are dying on the freeway. Think about that, none are dying. Seems weird. Like everyone that understands that they are loosing on a discussion, they either change the discussion or they go away.

I'm ok with you going. That's what people do when they are loosing an argument. If you should come back, after you rant and rage about how stupid I am, I would like to hear your take on why automatic transmission cars, are not dying on the freeway. I would love to know. Don't get so worked up that you forget to answer the question like the last post. I will bring the popcorn.

If you are in the Seattle area, I would love to buy you a beer. You and I could discuss the liberal issue that is contaminating my home town. 🍺


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## Cee-dub (Feb 20, 2007)

Aw, he didn’t just leave… he, like, _vaporized._


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## Butcher (Jan 31, 2001)

Ha! Maybe he is having a beer with Don. I Googled his power point, there is nothing about this so called relationship. Does not make it fact he does not have one, but maybe it's just a virtual one.


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## Butcher (Jan 31, 2001)

Those that are wondering, the poster left and the posts are deleted. No real loss


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## Rmthompson62 (3 d ago)

Darter said:


> The salesman, just before purchase, tried to convince me it is a non-interference engine. Quote "This is the 8 valve 2.0, not the 16, so it's a non-interference engine." I didn't go for it, since I thought 99.9% of all foreign engines are interference engines.
> Also, was there really more than one variety of 2.0 engine in '97? I'm guessing this guy was just telling me whatever he could to sell the car. My sis-in-law bought it, regardless of the engine type, but I want to know how urgent it is to change the timing belt at 82,000 miles.
> The salesman claims it was changed at 60K, but the service records will tell us that once we get them.


The 4 0 Passat is the only VW engine I can find that is non interference.


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