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Valve train Problems


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21 replies to this topic

#1 markjw

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Posted 11 July 2009 - 08:38 PM

I'm trying to help a friend fix his '91 loyale. We pulled the drivers side valve cover off and found a couple rockers,springs and a keeper laying in the bottom of the cam tower.

I have no idea what I should do next. 'cept maybe replace the whole motor. Anyone got a better idea? 160k on the motor and never abused.

Posted Image
Posted Image

Edited by markjw, 11 July 2009 - 08:41 PM.


#2 Gloyale

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Posted 11 July 2009 - 08:45 PM

Pull the cam carrier and replace the keepers and rockers. Use compressed air through the spark plug hole to hold the valve up tight to install the springs and keepers.

#3 markjw

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Posted 11 July 2009 - 08:48 PM

Can I install the springs and keepers by hand? Should I find diffrent/new keepers?

#4 GeneralDisorder

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Posted 11 July 2009 - 09:15 PM

No - you cannot install them by hand.

The way this sort of thing happens though makes it unlikely that a simple repair will do the job. Either the valve stuck in the guide, or the valve seat came out of the head and jammed it open - as a result the rocker arm fell out sideways and probably when the valve finally unstuck itself the rocker arm got caught between the cam and the spring - compressing the spring and allowing the keeper to fall out.

It is very likely that the engine will need a new head at this point - assuming no damage to the piston or cylinder occured from whatever jammed the valve.

Pull the head - can't hurt to look at this point.

GD

Edited by GeneralDisorder, 11 July 2009 - 09:20 PM.


#5 markjw

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Posted 11 July 2009 - 09:20 PM

Yeah...I figured it wasn't gonna be that simple.

At this point,we're gonna pull the motor and pull the head. Have a good look around.

Thanks for the advice.

#6 Gloyale

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Posted 12 July 2009 - 10:54 AM

No - you cannot install them by hand.

The way this sort of thing happens though makes it unlikely that a simple repair will do the job. Either the valve stuck in the guide, or the valve seat came out of the head and jammed it open - as a result the rocker arm fell out sideways and probably when the valve finally unstuck itself the rocker arm got caught between the cam and the spring - compressing the spring and allowing the keeper to fall out.



GD



It is also possible that someone incorrectly installed the rockers and the Cam Case. I would start by pulling the Cam case and checking the valve for free movement.

#7 GeneralDisorder

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Posted 12 July 2009 - 12:47 PM

It is also possible that someone incorrectly installed the rockers and the Cam Case. I would start by pulling the Cam case and checking the valve for free movement.


Without knowing more I can't discount that possibility, but from the sounds of it, it just happened out of the blue at 160k.... and I've seen this happen before - I've seen them snap the valve guide casting clean off and bend the valve. It's not a common failure, and I don't know definitively what causes it.... frankly IMO just one more reason not to run the EA82's. Since I stopped running them I've been a much happier person.

GD

#8 markjw

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Posted 14 July 2009 - 07:47 PM

The valve seems to have free movement. Almost like a suction in the valve stem. It feels right.

But,I'm suspicios of the head.Like GD said,what made it happen?

I'm going to take the head in to a machine shop. I'm wondering, aside from the usual service of checking for cracks,flatness and cleaning,
should I take all the parts I found and ask them to check it out,and if everything looks good, reassemble it with existing parts?

Or,should I just ask them to replace some stuff/everything?

If I do want them to replace parts,should I source and supply them?

What do you guys think? This motor is pretty sweet,otherwise. It is worth saving.

#9 bheinen74

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Posted 14 July 2009 - 08:41 PM

did you pull off the other side valve cover yet to see what kinda surprise it will have in store?

#10 markjw

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Posted 14 July 2009 - 09:19 PM

I did. It looks really good. While it was still in the car,a compression test showed 150lbs in both #1 and #3 cyl. #2 was at 0,and #4 was at about 5lbs.

Its the inside valve, on #2 cyl. is where the keeper let go.

But,both inside rockers were laying in the bottom of the cam case.

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#11 Gloyale

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Posted 15 July 2009 - 01:26 AM

I am betting on poor assembly at some point in the cars past.

If the valve is free moving, and the HLA (lifter, but not really) is not spongy, thne you should be fine to put the spring back on and go with it.

Use a big dab of grease on the end of the HLA to hold the rockers in place during assembly.

#12 Niku-Sama

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Posted 15 July 2009 - 01:31 AM

if both #2 and #4 have little or no compression i would rebulid/replace

arlington PaP has a ton of ea82 stuff right now, go grab yer self a head

#13 Gloyale

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Posted 15 July 2009 - 01:33 AM

if both #2 and #4 have little or no compression i would rebulid/replace

arlington PaP has a ton of ea82 stuff right now, go grab yer self a head


2 and 4 had no vavle operation for the compresison test. you can't take anything from those readings.

#14 GeneralDisorder

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Posted 15 July 2009 - 08:26 AM

I am betting on poor assembly at some point in the cars past.


I just can't see that - not and have it last for thousands of miles before failure. I mean - what could they have "poorly" assembled that would cause that? I tried to wrap my head around that the last time I saw one like this - it just doesn't add up though. If the cam case were loose enough for the rocker to fall out you would have huge issues beyond a rocker falling off. Not to mention a spectacular oil leak.

GD

#15 Gloyale

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Posted 15 July 2009 - 09:07 AM

I just can't see that - not and have it last for thousands of miles before failure. I mean - what could they have "poorly" assembled that would cause that? I tried to wrap my head around that the last time I saw one like this - it just doesn't add up though. If the cam case were loose enough for the rocker to fall out you would have huge issues beyond a rocker falling off. Not to mention a spectacular oil leak.

GD


Rocker cockeyed

Keeper incorrectly installed



I've taken apart ones that where running ok but when opened the rocker was sideways and riding on the spring.

#16 4x4_Welder

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Posted 17 July 2009 - 03:49 PM

Combine that with a keeper that hasn't been baked to the valve stem and it'll all pop apart.
In your FTE post, I didn't realize it actually popped the spring off and dropped the valve too- I've never seen an engine survive that before, but then again I've never seen a Subaru drop a valve.

#17 markjw

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Posted 17 July 2009 - 11:41 PM

I've never seen an engine survive that before, but then again I've never seen a Subaru drop a valve.


I have no clue why the valve didn't get sucked into the cylinder when the keeper let go. I wasn't driving when all this happend so,i can't say for sure what happend.

I do know the Rockers got tossed around a bit. The pads which ride on the cam were a bit marred up. So,I want to replace them. The cam survived well.
The lobes are in geat shape. Definitly reusuable.

My post over a FTE was mainly about putting New rockers on a existing cam.
And the effects it would have on the cam as far as wear. I talked to Terry about it at CCR and apparently,as long as there are no flat spots on the rockers or cam lobes,it should be fine. Pretty much what you said over at FTE. (thanks for the reply,by the way)

So,thats what I'm gonna do. Replace the stuff that was damaged,put it all back together,and go for it.

#18 4x4_Welder

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Posted 17 July 2009 - 11:44 PM

The general rule of thumb is that you can replace the followers or lifters without replacing the cam, but if you replace the cam you must replace the followers or lifters. You can get away with used roller followers as those don't match to the cam like flat tappets.

As I said over there, make sure everything else is in good shape. These things do pop out, but there's usually a reason.

#19 markjw

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Posted 17 July 2009 - 11:48 PM

What about a couple new valves? Can I just install some parts store valves into the seats that are in the head and call it good? I've been reading about lapping. It seems to be a controversial subject as to its validity.

#20 4x4_Welder

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Posted 18 July 2009 - 12:31 AM

I'd do a check on the valves to see if they need to be lapped. Use a magic marker, and color in the seating surfaces on both the valve and head. Use a lapping tool to spin the valve back and forth in the head for about 15seconds. Pull the valve back out, and check the marks. If there is good smooth consistant contact all the way around both the valve and seat, then install as is. If there is any spot in the seating ring that is not touched, then lap it until it is all consistant. If there is a gap along one side of the valve, and not the seat, then the valve is bent or there is a mis-alignment between the seat and guide.

#21 STI_Wolf

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Posted 18 July 2009 - 12:49 AM

I'd do a check on the valves to see if they need to be lapped. Use a magic marker, and color in the seating surfaces on both the valve and head. Use a lapping tool to spin the valve back and forth in the head for about 15seconds. Pull the valve back out, and check the marks. If there is good smooth consistant contact all the way around both the valve and seat, then install as is. If there is any spot in the seating ring that is not touched, then lap it until it is all consistant. If there is a gap along one side of the valve, and not the seat, then the valve is bent or there is a mis-alignment between the seat and guide.


What I've done in the past when the valves don't seat fully is take an electric drill and some grinding paste stuff.. (like liquid sandpaper) attach the valve stem to the drill.. and pull up with the drill, with the valve in the head.. takes a few minutes and guarantees a good tight fit

#22 4x4_Welder

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Posted 18 July 2009 - 12:29 PM

I wouldn't go that far, you don't want to damage the valve stem. I would only hand-lap, if needed, using Clover Compound. Start with the coarse, and work your way down to the extra-fine until you just have a matte finish. Typically, a good three-angle job will have very little contact area, but a larger contact area isn't a bad thing. The valve will stay cooler and seal a little bit tighter.




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