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Slipped valve guides ticking noise 05 Impreza


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Disconnected the exhaust from heads to raise engine while adjustind valve lash. The exhaust were at .013 instead of .010. I looked in the exhaust ports and the valve guides have dropped due to carbon build up. Does the dropped guide make the ticking noise, or it just the valve lash out of spec. making the ticking?

post-35628-0-72603600-1487567656_thumb.jpeg

Edited by steve56
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What makes you think the guides have dropped? Can you take a picture in the exhaust port?

 

The bigger the lash, the louder the tick because the rocker is moving faster before it hits the valve stem. Too small of a lash and the valve won't fully close when it gets hot and expands in length. When it doesn't close tightly on the seat, it can't dump heat and it quickly burns. So looser is safer than tight.

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What makes you think the guides have dropped? Can you take a picture in the exhaust port?

 

The bigger the lash, the louder the tick because the rocker is moving faster before it hits the valve stem. Too small of a lash and the valve won't fully close when it gets hot and expands in length. When it doesn't close tightly on the seat, it can't dump heat and it quickly burns. So looser is safer than tight.

I pulled the exhaust away from the bottom of heads. I can look right up the exhaust ports. Never seen exhaust guides drop before. Thought I was doing a simple valve lash adjustment and now Ive got to pull the heads, replace guides or get a different set of heads. I will ad some pics to my original post when i get the lighting and and camera angle right.

Edited by steve56
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Can't get a good picture because of the angle/lighting but on one of the exhaust ports all you can see is the guide. On all other exhaust ports  you see the nub of the valve guide and then the valve stem. Can this guide come completely out of the seat and wreck my engine?

Edited by steve56
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Yup, that's screwed! There can't be much guide left in the head, it's gone all the way down and mushroomed over the bigger part of the stem of the valve it looks like. Wow! I'm amazed it's not missfiring. Try turning the engine over with a bar and watch the guide, I bet it's moving with the valve and poking in and out of the head. The hole it presses into in the head is probably too wallowed out at this point to press a new guide in, so you're looking at a replacement head. Consider it lucky that valve hasn't broken and destroyed the piston yet.

 

I would also think the guides dropped due to overheating rather than carbon. If the headgaskets have been dripping coolant out, it could have gotten low at some point.

 

Thanks for taking the picture!

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Yup, that's screwed! There can't be much guide left in the head, it's gone all the way down and mushroomed over the bigger part of the stem of the valve it looks like. Wow! I'm amazed it's not missfiring. Try turning the engine over with a bar and watch the guide, I bet it's moving with the valve and poking in and out of the head. The hole it presses into in the head is probably too wallowed out at this point to press a new guide in, so you're looking at a replacement head. Consider it lucky that valve hasn't broken and destroyed the piston yet.

 

I would also think the guides dropped due to overheating rather than carbon. If the headgaskets have been dripping coolant out, it could have gotten low at some point.

 

Thanks for taking the picture!

Yes I've never seen a valve guide like that. Noticed that head had a Felpro head gasket and other side original head gasket. So something happened. Overheating sounds like the probable culprit. Ive got a good set of heads to put on if necessary.

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That guide would have to be replaced and staked in place to make sure the new one doesn't drop out as well.

 

It happens occasionally on the 00+ engines. Not necessarily due to overheating, they just do it. Have it replaced by a machine shop and have the others checked and staked.

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That guide would have to be replaced and staked in place to make sure the new one doesn't drop out as well.

 

It happens occasionally on the 00+ engines. Not necessarily due to overheating, they just do it. Have it replaced by a machine shop and have the others checked and staked.

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That guide would have to be replaced and staked in place to make sure the new one doesn't drop out as well.

 

It happens occasionally on the 00+ engines. Not necessarily due to overheating, they just do it. Have it replaced by a machine shop and have the others checked and staked.

Thanks for the reassuring information. I had never seen a dropped guide like that before.

Edited by steve56
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