Bent Valves?
07-14-2007, 06:18 PM
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Bent Valves?
I just bought a 1.8 t from a guy and it wasn't running he told me that it ran but it had very bad compression. He told me that it needed new piston rings. So i took the head off and when i did 3 of the valves were'nt flush with the head. Isn't that a sign of bent valves and if so wouldnt that be the reason it had bad compression. What i think happennend and the guy didn't know about it was that his timing bel broke because the timing belt looks brand new along with the tensioner. What do you all think. Thanks
07-14-2007, 06:38 PM
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You sound promising.
I think you are on the right track.
Are the piston's nicked... like the same piston as those bent valves... in the right place for those valves???
Yeah the timing belt let go and he bent a few valves... I suggest that you replace them with original equipment valves... lap them in properly. Or have a machine shop do the work for you.
Search for bent valves or broken timing belt on the forum... the 1.8T has quite the history.
Are the piston's nicked... like the same piston as those bent valves... in the right place for those valves???
Yeah the timing belt let go and he bent a few valves... I suggest that you replace them with original equipment valves... lap them in properly. Or have a machine shop do the work for you.
Search for bent valves or broken timing belt on the forum... the 1.8T has quite the history.
07-14-2007, 06:43 PM
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Re: You sound promising.
Nope no nicks in the pistons, that what made me question if the valves were bent I haven't pulled them yet and if I don't have to i don't want to.
07-14-2007, 08:16 PM
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If the valves bent because it hit the piston there would be signs of it on the top of the pistons.
Issue could be that the valve springs have failed causing those valves not to close all the way.
07-14-2007, 08:34 PM
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My experience leads me to believe spring failure is not common on the 1.8T
It is not impossible tho... but I've yet to encounter it. Actually I've never seen a valve spring fail on a 1.8T. I think I've seen a lifter or two replaced... I've seen many failed belt drives, failed cam chain tensioners.
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07-14-2007, 11:13 PM
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Re: The day I picked up my car from DRS after they built my 2 liter the first time
So you think its the valve springs. There is no damage to the pistons and 3 of the valves are about 1 mm from being flush with the head. I've worked on other cars before and every time this has happenend the valves were bent. I'll take a picture in the morning and post it.
07-15-2007, 06:23 AM
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Is it 1mm all the way around the valve or just on 1 side?
Have you tried pushing the valves down further? My valves were slightly bent but were still able to seal, they got bent because of valve float when pushing the engine past 8k rpms. I also had marks on 3 of my cylinders because of it.