# 2.0 AEG - NO Compression on #4 Cylinder



## JD0770 (Dec 2, 2009)

My wife has an 01 Beetle with 120K on the 2.0 AEG. Daily driver that she babies! Last week she called complaing about hesitation/bucking at idle. Pulled OBD2 codes and had #4 Cylinder Misfire. Pulled the spark plug and it was wet with fuel. Replaced it along with wires and ignition coil. Still no luck. I did a compression test and had approximately 180PSI on Cylinders #1 - #3. I'm not getting any compression on #4. Barely moves the gauge when cracking over! 
I'm taking off the intake mani tonight along with the valve cover to see if anything pops out at me. 
Any ideas would be great!
P.S. Replaced timing belt, water pump, timing belt tensioner, aux belt, tranmission fluid and filter, plugs, wires, t-stat and fluids at 90K.
Miticulous oil changes at 4,000 mi (mainly drives highway and really babies the car)


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## Jay-Bee (Sep 22, 2007)

*FV-QR*

I'm going to guess a bent valve or something of the likes, head gasket wouldn't drop to 0 compression, and you would most likely see it affected on more than one cylinder, along with massive coolant/oil burning.


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## JD0770 (Dec 2, 2009)

*Re: FV-QR (Jay-Bee)*

I'm also suspecting a bent vavle. Not sure how to troubleshoot though? I pulled the intake manifold last night and removed the valve cover. First time seeing the "internals" of a 2.0. Do I need to pull the rest of the head? 
also got a friend suggesting to replace the entire engine with one from an 04-05? any suggestions?


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## Jay-Bee (Sep 22, 2007)

*FV-QR*

A later engine will "work" just keep the AEG electronics, and to bend a valve it usually means valve to piston contact... but some people have very little damage to the pistons when it happens, you can't tell without removing the head unfortunately.


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## JD0770 (Dec 2, 2009)

*Re: FV-QR (Jay-Bee)*

do you know the actual engine codes that will swap in? I think AVH. Not sure what others.


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## Jay-Bee (Sep 22, 2007)

*FV-QR*

AEG/AZG/AVH/BEV will all work, BBW is the last 2.0 to be built and is still used today I think in the Canadian/Mexican "City" models, it has a funky cam/cam gear/CPS setup, stay away from that.
You pretty much just need a "short-block" engine, and can swap everything onto it.
Heads can go for cheap if you find the right seller, I scored an AEG one with everything except the valve cover and manifold studs for 60$.


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## digraph (Jul 23, 1999)

*Re: 2.0 AEG - NO Compression on #4 Cylinder (JD0770)*

You're probably better off swapping in a working engine because unless you're sure, your AEG may have the incorrectly installed piston ring.
I busted a spring in my AEG and the mechanic pulled the head, cleaned it and replaced the spring. In retrospect, even though my car is running fine now, I'm still burning oil and have that same lower compression in the one cylinder. All for the same cost as a new -used- engine.
Of course, getting a new engine isn't a sure thing unless you have all the information about it.


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## JD0770 (Dec 2, 2009)

*Re: 2.0 AEG - NO Compression on #4 Cylinder (digraph)*

thanks for the advise guys. I will update when I finish.


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## JD0770 (Dec 2, 2009)

*Re: FV-QR (Jay-Bee)*

Jay BEE,
Got someone telling me an AZG will not work? Can you help a brother out before I go spending $600 on a motor!
Thanks


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## Jay-Bee (Sep 22, 2007)

*FV-QR*

The block and head are the same, yes the electronics are different, keep the AEG wiring and sensors, only problem I can see coming up it that they use different coilpacks, so the AEG coilpack might not bolt on as neatly (or possibly at all) easily fixed with a little custom work.


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