98 Passat 1.8 20v engine vibration

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Fri 17 Nov 2006 15:27
98 Passat 1.8 20v engine vibration - bk.bas
A long one, so please read all if you can help me.
I have a 98 1.8 20v estate, 76K miles, that has a slight engine vibration, rising through the revs. The top end was rebuilt recently after cambelt failure (well before supposed VW recommendation). I refitted recon head myself. Used new stretch bolts and all new gaskets. Torque 45/60/180degrees. Initially seemed to run fine and compression ratios were all OK. at 7 bar Also needed to fit new catalyst as old one snapped at ball joint (probally due to standing outside for 6 mnths!). Vibration started to appear after a few hundred miles. This model was always gutless, but I think it feels a bit more sluggish than it used to, but that might just be paranoia after the rebuild. Always starts no problem and runs OK apart from the vibration. I'm at a loss on this one as I think it unlikely that valves would be OK to start then start leaking...other thought is hd Gasket, but there is no 'mayonaise' around the oil filler cap and no coolant loss. Coolant appears oil free. I have'nt rechecked the compression yet, but will -any other suggestions whilst I have it in bits. I also intend to check the head bolt torque in case I miss tightened any(??!!). Not sure what the overall torque will be after the 180deg turn but I will just keep creeping the torque up by a couple of Nm above 65 on each bolt in sequence until they're all the same unless anyone knows what the actual final torque would ? IS this likely to have any adverse effect on the stretch bolts or the Hd gasket? Any info or help welcome. I've hated this car since I got it...VW reliability is a myth
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Sat 18 Nov 2006 09:02
98 PAssat 1.8 20v engine vibration - braindead
that sounds terminal (big ends) i hope for your sake im wrong
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Sat 18 Nov 2006 10:58
98 PAssat 1.8 20v engine vibration - Hamsafar
As the bolts are stretsch bolts its unlikely to be them unless you left them sticking out, you can make sure they are all done up, but the amount of tightening isn't THAT critical, once they start to stretch, the amount of compression they apply to the head is fairly linear until they snap.

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Tue 5 Dec 2006 22:08
98 PAssat 1.8 20v engine vibration - yogi69
Im sure on these models there is a big tensioner on the side of the head for the cams, this is a nown fault with the 20v and can cause some problems.
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Sat 9 Dec 2006 01:28
98 PAssat 1.8 20v engine vibration - bk.bas
do you mean the cambelt tensioner on the front of the block (which is fine) or something else. The only tensioner for the actual cams on the ADR engine is the solenoid operated one that sits between the cams at the back of the head and (I assume) adjust the realtionship between the cams via the ECU. Not aware of any faults with this, but I could take the rocker cover off and watch to see if it varies with engine revs??? Or am I guessing out my backside here
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