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I have a 99 ej25 with a ton of miles but it had been rebuilt (with receipts) when I bought it. Recently I noticed it shaking like crazy when it was stopped and finally it through a code, miss fire number 4. imagine that. So i went through the typical things, plugs, wires, checking the ground, sea foam, injectors, timing, etc etc etc. Nothing helped. I got to thinking, I bet i have a burnt or sticky valve. I cranked it up and put a dollar bill near the exhaust it sucks the dollar bill in and turned it black. So i decided to pull the number 4 injector and see if it would stop. well... it didn't. So i plugged it back in and pulled the number 2 injector. the suction stopped. That is odd. I wound't figure that a burnt or non working valve on one cylinder would cause a code on another. At this point i am not sure what i am going to do. I just put a brand new set of snow tires on her 50 miles ago. I may just drive it until I dies. 

IF anyone has any suggestions on this please feel free to give me some hints or advice. 

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I'm not clear on what you mean the suction stopped when you pulled the wire on #2 injector. Did the engine run any different when you pulled the #4 injector plug? If not, you've isolated it to that cylinder.  It's not unheard of for these engines to burn an exhaust valve, but it certainly isn't the first place I'd go checking. First off, what do you mean by rebuilt, it had headgaskets done? That's usually what people mean when they say a subaru engine was rebuilt.

 

First off clarify what you mean on pulling the injector wires. If pulling the wire doesn't change how it runs, clearly that's the problem cylinder. Since someone was in there mucking around it might be worth pulling the valvecovers and checking the exhaust valve clearances. If they're too tight you could have burned a valve. The other thing you should definitely check is the timing timing belt timing. If you have a loose or failing tensioner you could have jumped time on one of the cams or crank. 

Edited by 987687
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I'm not clear on what you mean the suction stopped when you pulled the wire on #2 injector. Did the engine run any different when you pulled the #4 injector plug? If not, you've isolated it to that cylinder.  It's not unheard of for these engines to burn an exhaust valve, but it certainly isn't the first place I'd go checking. First off, what do you mean by rebuilt, it had headgaskets done? That's usually what people mean when they say a subaru engine was rebuilt.

 

I was checking to see if the exhaust had suction on it while running, by putting a dollar bill over the exhaust. It has had suction, but when I pulled the number two injector the suction stopped. I have never heard of a non turbo engine burning an exhaust valve it may just not be closing good. A couple of days ago i checked the timing and replaced the tensioner. I even ran the engine while putting extra tension on the tensioner. I will have to look at the receipts but I am pretty sure it rebuilt with new rings, pistons, head gaskets etc. I cannot speak for how well it was rebuilt thought. I bought the car from my mother in law. This is probably the 5 or 6th subaru I have owned. I plan on pulling the valve cover and checking the valve clearance. I just found it supper odd for it to throw a code on number 4 and have valve problems on number 2. When it was idling and i pulled the number 4 injector there was no change in the idle but when i dove it with it un plugged  there was a huge difference. The car seems to run well once you get it going, the bottom end lacks some power but that is about it. The whole engine shakes hard at idle but doesn't seem to be missing, There is a knock around the number 2 cylinder but its not too bad and seems to be worse at idle.  

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Well, if it's missing on cylinder 4 at idle it may very well be because of a tight exhaust valve or incorrect valve timing (timing belt off). Since 2 and 4 are on the same bank I can understand why it would run more smoothly on just 1 & 3 than with 4 misfiring and 2 firing. So that's not entirely odd in my mind. 

 

Since the engine seems to pick up at higher speeds/loads it probably isn't a bad spark plug or wire, that usually points to either valve timing, valve clearance, or a burned valve. I have heard of burned valves on n/a engines, if you look around you'll find treads on it, but it isn't at all common.

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Well, if it's missing on cylinder 4 at idle it may very well be because of a tight exhaust valve or incorrect valve timing (timing belt off). Since 2 and 4 are on the same bank I can understand why it would run more smoothly on just 1 & 3 than with 4 misfiring and 2 firing. So that's not entirely odd in my mind. 

 

Since the engine seems to pick up at higher speeds/loads it probably isn't a bad spark plug or wire, that usually points to either valve timing, valve clearance, or a burned valve. I have heard of burned valves on n/a engines, if you look around you'll find treads on it, but it isn't at all common.

 

 

That totally makes since.... I know the timing is on and that the wires and plugs are good. So i would say that I have a valve problem on number 2 that is causing problems on number 4 cylinder as well.  Sounds like a good theory to me. I will try and pull the valve cover off today. I am sure that isn't going to be a fun job considering how much fun changing the plugs was on that side.  I have done it years ago on a buddys and remember having to jack the engine up to get the cover out. I will report back once I get it off. 

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That totally makes since.... I know the timing is on and that the wires and plugs are good. So i would say that I have a valve problem on number 2 that is causing problems on number 4 cylinder as well.  Sounds like a good theory to me. I will try and pull the valve cover off today. I am sure that isn't going to be a fun job considering how much fun changing the plugs was on that side.  I have done it years ago on a buddys and remember having to jack the engine up to get the cover out. I will report back once I get it off. 

 

I don't have hands on experience, but recently had a buddy replace the valve cover gasket on my '99 with 2.5 motor. He said the job wasn't bad at all. Got both valve cover gaskets swapped out in not much more then an hour. Said he went to u-tube to see videos on how to do the job. You may want to see the videos as well. Hope these thoughts help.

Edited by Rooster2
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That totally makes since.... I know the timing is on and that the wires and plugs are good. So i would say that I have a valve problem on number 2 that is causing problems on number 4 cylinder as well.  Sounds like a good theory to me. I will try and pull the valve cover off today. I am sure that isn't going to be a fun job considering how much fun changing the plugs was on that side.  I have done it years ago on a buddys and remember having to jack the engine up to get the cover out. I will report back once I get it off. 

 

I don't have hands on experience, but recently had a buddy replace the valve cover gasket on my '99 with 2.5 motor. He said the job wasn't bad at all. Got both valve cover gaskets swapped out in not much more then an hour. Said he went to u-tube to see videos on how to do the job. You may want to see the videos as well. Hope these thoughts help.

 

 

 

I am going to maybe try it this evening. I just got off the phone with a friend that have a super nice code reader, a lot better than mine. He said his will give a lot more info on how the engine is running and would maybe give some more info. 

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Oh shoot, you said 99 ej25, I stupidly assumed you meant a single cam, when you said plugs sucked to change I realized you may have a dual cam motor... Both were available depending on legacy/impreza.

 

If you have the dual cam motor you can't actually set the valve lash with adjusters, you have to take the cams out and it's a horrible mess... You can still check them, though. Pulling the cover is a lot easier than changing the plugs.

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Oh shoot, you said 99 ej25, I stupidly assumed you meant a single cam, when you said plugs sucked to change I realized you may have a dual cam motor... Both were available depending on legacy/impreza.

 

If you have the dual cam motor you can't actually set the valve lash with adjusters, you have to take the cams out and it's a horrible mess... You can still check them, though. Pulling the cover is a lot easier than changing the plugs.

oh man, I didn't realize that they are not adjustable like the sohc are... Just my luck.. I did though do the dollar bill trick again. and this time there was no change when i pulled the number 2 injector... One thing that i did notice is that at idle when i pull the number 4 injector there is no change in the engine... I am going to do a compression check and see what come up then. If it is bad I may just run her till she dies. It seems to run fine at high idle and speeds,  I went through the receipts and less than 20k the engine was completely rebuilt. heads surfaced, cams turned. etc. so I am hoping that the compression check comes back good but i have a feeling that it isn't going to be that way. 

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Well I figured i would give an update even though its not a good one.... I ran a compression test and it was at 0 the spark plug looked good no oil or coolant. I am pretty sure either my valve is burnt or stuck open, if its stuck open then it must not be too bad because the piston isn't hitting it, or maybe the piston has already bent it and now its stuck open. I may never know...I will probably just run it with a dead cylinder... The car has around 240k miles and I am pretty sure the guy who rebuilt it did not do a very good job.

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As I said, rebuild usually doesn't actually mean a rebuild... Usually it's just headgaskets. Sadly there are a lot of scam artists in the automotive repair industry. If the rest of the car is in good condition, your best course of action is to do a 2.2 swap. Long story short a 2.2 from a 95 automatic legacy is the best option, but there is a lot of information on this forum on exactly what you need.

Edited by 987687
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I may just part it out... The mechanic I am pretty positive did do the rebuild. There was a receipt from the machine shop for the crank and heads. I think he may have just not shimmed the valves the right way. I will sleep in what to do. Its not a daily driver we mainly bought it for when it snows. 

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I pulled the valve cover tonight just to see if there was anything noticeable...everything looked good, but you really cannot tell much from that side. the exhaust valves seemed to have plenty of pressure on them i used a plastic pry-bar to push them in and out. If i drop the bottom exhaust pipe could i see the valves with a bore camera? I thought about sticking one through the spark plug hole but i would never be able to turn it around to see the valves.

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You can only see the valves from inside the combustion chamber, you can see the valve stem and seal from the exhaust port, but that won't tell you much. If it was rebuilt recently there's a chance the mechanic might honor his work, it's pathetic to rebuild an engine and have it blow up...

Edited by 987687
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Its confirmed..Its a burnt exhaust valve... I dropped the exhaust and used a bore camera to check the valves and number 4 left valve is burnt I too a pic but it didn't turn out too good. That is an easy to check your exhaust valves. Thanks everyone for your suggestions and comments. 

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