# Is 2.0 an interference engine?



## Dano123 (Sep 19, 2008)

I've heard differing opinions, anyone weigh in with a definitive answer, pls and thank you...maybe someone who bent some valves at some point?
It's in a '99 Golf.
Thanks


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## Jay-Bee (Sep 22, 2007)

*FV-QR*

Yes, but you can sometimes get away with a timing belt snapping and no valve damage *sometimes*, there is only 8 of them in there.


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## 2LTurbo (Aug 26, 2008)

id like to see some pics of bent valves in an 8v due to timming belt slippage


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## dangerous_dave (Jun 28, 2006)

*Re: Is 2.0 an interference engine? (Dano123)*

is your 99 golf a mk4? if yes then it is an interference motor. 99 and down aba 2.0 motors are non interference


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## 2LTurbo (Aug 26, 2008)

what to elaborate why? as the obd2 mk3 head is IDENTICAL to the mk4 aeg head


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## dangerous_dave (Jun 28, 2006)

*Re: (2LTurbo)*


_Quote, originally posted by *2LTurbo* »_what to elaborate why? as the obd2 mk3 head is IDENTICAL to the mk4 aeg head

dont know. all i do know is when the belt on my old 96 jetta broke all i did was replace the belt.

why is the sky blue, how does posi trac on a 69 plymouth work? i dont know it just does.


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## FL 2.0L (Aug 1, 2002)

There was a thread on here not long ago of an ABA bending valves with a timing belt (actually tensioner) failure...


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## 2LTurbo (Aug 26, 2008)

they are alll interference engines... ive had a belt snap on the highway, all i did was change the belt, but i got lucky, the clearences are not likely to cause problems but it is possible!


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## Darren337 (Mar 5, 2007)

Isn't interference kind of a LACK of clearances?


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## DustinM (Apr 2, 2008)

*Re: (Darren337)*

Yes, interference engines move the piston to the point of contact with a fully opened valve if the timing is wrong.
AFAIK the ABA is an interference engine, meaning that it's possible for the piston to hit the valves if your timing belt fails.


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## Pitsy (Oct 27, 2007)

*Re: Is 2.0 an interference engine? (Dano123)*

If you consider the fact that most timing belt failures occur at high RPMs, there is the possibility of valve float to contend with. I know if you park the piston at TDC with the timing belt removed, and turn the cam by hand, the ABA proves to be non-interference. I also know that I've seen bent valves and dented pistons in ABAs after belt failures.


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## 2LTurbo (Aug 26, 2008)

pitsy your spot on... couldnt remember the term, its valve float you need to worry about most on these engines at high speeds


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## Pitsy (Oct 27, 2007)

*Re: (2LTurbo)*

I thought about this while I was sleeping. Even with valve float, for a valve to hit the piston things must be really close to start with. I don't know what the actual measurements are, and stock ABA pistons are dished. Still, it might be cheap insurance to have some valve pockets machined in if you're swapping pistons or intend to run at high RPMs. Just a thought... I'd do some testing before making a decision.


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