loud clattering noise from head

[andrew4g63]

i think my buddys car might have bent some valves after doing a timing job. When its started a loud clattering comes from the head and lots of white smoke comes out the exhaust. the timing is dead on now but before the timing was off a couple of teeth. I did a compression test and the numbers were 160 across all four cylinders. Whats a way to check for bent valves without removing the head. If you guys have any sugestions on what could be wrong please chime in.

 

[805DSM]

rotate the crankshaft to the right , ..u rotate it from the crank pulley..and ull feel the pistons hitting the valves..

 

[chrisfullwood]

in my experience, if the valves we're bent then you would see the compression numbers dropping. i could be mistaken, but this recently happened to me.
ive had the timing belt jump a couple of times, and had no problems.
but this last time the tensioner colapsed, and the valves met the pistons, and now my compression numbers spike at 120, but rapidly bleed down to zero.

maybe that will help. i would heartily suggest replacing your tensioner, belt etc......
so that you dont have to do what i now have to do.

 

[andrew4g63]

ya already replaced all the belts and tensioner

 

[DSM90AWD]

Had a similar thing happen to me. Belt slipped a tooth on the crank sprocket causing the valves to tap the piston tops. Reset the belt and compression tests showed was ok as did a cylinder leakdown test (which is also a good idea for you)

 

[91TSiChick]

Yeah I'm kind of having the same issue with my 91 TSi. The noise isn't from the head itself but the belt tensioner pulley. So we ordered a new one and we are thinking it would be a good time to replace the other tensioners as well.

Cause on mine you can watch that pulley and you can't focus on it as its vibrating alot.

I would definately try rotating it and seeing if you can tell if those are meeting your valves. Might be a good idea for me to try that as well

~Michelle~

 

[1gdsmraider]

interference engine... if the valves are meeting the pistons you wouldn't be able to rotate without force or some sort of friction bending valves, damaging the dome.