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General => General discussion => Topic started by: richandhazel on 16 October 2006, 13:47

Title: Cambelt stripped teeth!
Post by: richandhazel on 16 October 2006, 13:47
My mate had asked me to replace his cambelt on his 1.8 20V Passat. It was due at 80k so with his current mileage at 78k we were planning on doing it very soon before the weather got much colder. Unfortunately it didn't make it. His wife was driving it home Saturday night when it broke down.
Further inspection has revealed that all the teeth have been stripped at the crankshaft cog and it look like no.1 cylinder exhaust valves are damaged as the valves appear to be staying open. About to whip out the cams and then it looks like the head will have to come off :cry:
Title: Re: Cambelt stripped teeth!
Post by: Uruk Hai on 16 October 2006, 13:56
Sounds like fun mate, good luck  :smiley:
Title: Re: Cambelt stripped teeth!
Post by: Martz on 16 October 2006, 13:58
My mate had asked me to replace his cambelt on his 2.0 20V Passat. It was due at 80k so with his current mileage at 78k we were planning on doing it very soon before the weather got much colder. Unfortunately it didn't make it. His wife was driving it home Saturday night when it broke down.
Further inspection has revealed that all the teeth have been stripped at the crankshaft cog and it look like no.1 cylinder exhaust valves are damaged as the valves appear to be staying open. About to whip out the cams and then it looks like the head will have to come off :cry:
Title: Re: Cambelt stripped teeth!
Post by: richandhazel on 18 October 2006, 04:01
Cams are out now, leak down test carried out and air is coming straight out into the exhaust manifold on all 4 cylinders. Not looking good.
Title: Re: Cambelt stripped teeth!
Post by: AudiA8Quattro on 18 October 2006, 09:19
Probably time for a new head, or maybe a new engine.
Title: Re: Cambelt stripped teeth!
Post by: kniterider on 18 October 2006, 12:38
i bent 17 of my 20 valves..., there should be a health/financial warning on these engines  :laugh: if the pistons are ok (mine had tiny thumbnail marks in them but still ok.... :huh: ) you can get a head, just make sure its the right one as it makes it easier to get one all in rather than changing turbo cams for n/a cams etc...... the heads are the same just inlet port diffo between models.., but then saying that id go for the complete engine route if i had a mk4 again and it happened the time it took to do and the money it cost a complete second hand engine could be dumped in in half the time..

Title: Re: Cambelt stripped teeth!
Post by: AudiA8Quattro on 18 October 2006, 12:43
If there is any damage to the pistons then they will have to be skimmed or replaced, i wouldn't even trust relatively small damage on the crowns, this will promote hot spots, and so pre-ignition.
Title: Re: Cambelt stripped teeth!
Post by: richandhazel on 18 October 2006, 15:02
Just removed the head. Every single valve is bent!

Have taken pictures that I will post.
Title: Re: Cambelt stripped teeth!
Post by: richandhazel on 18 October 2006, 15:30
Not good, bare in mind camshafts are removed so valves should be closed..............

(http://img.photobucket.com/albums/v603/richandhazel/Passat/DSCN0909.jpg)

(http://img.photobucket.com/albums/v603/richandhazel/Passat/DSCN0907.jpg)

(http://img.photobucket.com/albums/v603/richandhazel/Passat/DSCN0905.jpg)

(http://img.photobucket.com/albums/v603/richandhazel/Passat/DSCN0903.jpg)

(http://img.photobucket.com/albums/v603/richandhazel/Passat/DSCN0902.jpg)

(http://img.photobucket.com/albums/v603/richandhazel/Passat/DSCN0901.jpg)


............and to think, the timing belt wasn't even due :shocked:
Title: Re: Cambelt stripped teeth!
Post by: richandhazel on 18 October 2006, 15:37

(http://img.photobucket.com/albums/v603/richandhazel/Passat/DSCN0913.jpg)

(http://img.photobucket.com/albums/v603/richandhazel/Passat/DSCN0912.jpg)

(http://img.photobucket.com/albums/v603/richandhazel/Passat/DSCN0911.jpg)
Title: Re: Cambelt stripped teeth!
Post by: kniterider on 18 October 2006, 15:42
them there pistons are stuffed too... new engine time i thinks...... well your mates the new score holder now... 20 out of 20 eh... lol... mine must have been a gentle stack up as valves werent bent as much as them and piston damage was minimal
Title: Re: Cambelt stripped teeth!
Post by: Martz on 18 October 2006, 16:34
Rich

That brings back memories of mine. Scrapyard for a new lump.
Title: Re: Cambelt stripped teeth!
Post by: turbodub on 18 October 2006, 16:40
One of the advantages of having an 8v..........in fact it's the only advantage of having an 8v lol
Title: Re: Cambelt stripped teeth!
Post by: AudiA8Quattro on 18 October 2006, 18:59
Doesn't matter, you could do that sort of damage at idle, the 20v is an 'overpacked' engine  :sad:
Agree with above, new engine time.
Title: Re: Cambelt stripped teeth!
Post by: richandhazel on 20 December 2006, 04:11
Just thought I would update you on this.
Head went for overhaul at Roe engineering. Head was chemically cleaned and tested.
8 new exhaust valve guides fitted. 8 new exhaust valves, 12 new inlet valves all cut in. 0.006" skimmed off the head. Pressure tested.
Fully reassembled.
Came back looking brand new. Total cost: £562 incl vat. Also came with head gasket set and new cylinder head bolts.

The damage to the block and pistons was cleaned up and deemed negligeable. Its all back together now and running.

Interesting point that arises from all of this. The guy at Roe engineering has had to do a lot of these 20V heads, seems to be a common failure. I know that the Haynes manual isn't exactly 'the bible', but they do recommend halving the timing belt service interval from the VW stated 80K to 40K :shocked: I'd go along with that.
Title: Re: Cambelt stripped teeth!
Post by: dubslug on 22 December 2006, 15:20
there good lads at roe engineering, i had a head chemically cleaned and skimmed,but needed it back the next day as it was only day i could get a ride there, they stayed late to get it all done for me, top guys
Title: Re: Cambelt stripped teeth!
Post by: richandhazel on 22 December 2006, 15:46
They are good. How much did it set you back Rik?

Title: Re: Cambelt stripped teeth!
Post by: dubslug on 22 December 2006, 15:49
to be honest rich i couldnt tell u, i dont think it was that much though.
i had to have it done on my last car when doing 2l up grade