sidekickin Posted October 15, 2003 Share Posted October 15, 2003 Hey everyone, Got a problem with my '87 4WD STD Hatchback with EA81 engine and hydraulic lifters. Engine runs great and smooth at idle with no noise at idle or startup. However, when the engine is under a load...such a revving the engine or accelerating...the car almost acts like one of the cylinders is not hitting real well. It is very hard to describe the noise it makes, but it sounds like a low pitched exhaust leak sound (almost a rumble...but not bearing rumble!) from the right side of the engine. And when it makes this sound, it is like the car is not hitting on all 4 cylinders. And it only does it when the engine is under a load. Since it has started doing this, I have noticed that the engine has lost some of its power also. I haven't read any posts addressing this problem, but it seems to be a common noise from this engine because I hear quite a few older Subes going down the road making this noise. The engine has a very slight valve train tap on the right side of the engine, but it is only noticeable with the hood up and my ear at the valve cover. And it doesn't make any valve noise on startup and any loud clacking valve noise when under a load. The engine does not lose coolant or burn any oil. I had read about the cylinder heads cracking between the valve seats, allowing the compression to seep past the exhaust valve during combustion, but have only heard about that problem on EA82s. Was this a problem with EA81s, or is there another cause for my problem? Any help is greatly appreciated. Link to comment Share on other sites More sharing options...
GeneralDisorder Posted October 15, 2003 Share Posted October 15, 2003 It's hard to tell from your description, but I would start checking your ignition system components - sounds like you could have a miss or something. Try replacing your cap and rotor and wires. Maybe a new coil as well. The crack between the valves is an EA82 thing as far as I know. Never heard of that affecting an EA81. Maybe you do have an exhaust leak - the gaskets at the heads could be the culprit. EA81's don't like exhaust leaks, and you will experience a good deal of power loss from that. I am also thinking of the Air Suction Valve - those will vent exhaust gasses into the engine compartment when they get bad, and they make a similar noise to what your describing. And there are two of them on some engines - one at either head. GD Link to comment Share on other sites More sharing options...
JonOfScio Posted October 15, 2003 Share Posted October 15, 2003 I've had both electrical problems plague my car as well as stupid exhaust problems, so my guess is it's probably either a head gasket, or exhaust gasket... Link to comment Share on other sites More sharing options...
sidekickin Posted October 17, 2003 Author Share Posted October 17, 2003 Hey guys, Thanks for the replies. After taking a look at it, it does appear that I have a bad Air Suction Valve. If I cover the hose when I pull it off the ASV, the noise disappears and it is quiet. Now the new question is how do I bypass this thing so I don't have to buy a new one? Any suggestions on what to use to plug the pipe that comes up from the exhaust manifold? And could a malfunctioning Air Suction Valve cause a power loss or a miss, or is that another problem? Thanks again for all your help! Billy ________ 1987 STD 4WD Hatchback EA81 w/hydraulic lifters Link to comment Share on other sites More sharing options...
TomRhere Posted October 17, 2003 Share Posted October 17, 2003 Although the EA-81 and EA-82 engines have different methods of attaching those tubes to the exaust, I used the same method of blocking them on both of my BRATs. I cut the tubes off of the attachment point at the exhaust. Then I cut the head off of an allen head bolt and welded it to the connection for the tubes. After doing that, you can remove all of the associated components that are connected to the tubes. Really cleans up the engine bay. The ASV's have been known to go into Nuclear meltdown, and cause problems with the carburator. Some of the plastic from inside of the ASV will get into the bores of the carb and cause you headaches. But I don't think it would cause missing or stumbling, could be wrong. When was the last time she was given a good tune-up? Could be the carb is dirty inside, try some fuel system cleaner, maybe a couple of tanks worth. Where in Ohio are you? A few other members are from Ohio, and I'm only 20 miles north of the border. Plus Miles Fox is just over the border in Indiana.... Link to comment Share on other sites More sharing options...
GeneralDisorder Posted October 17, 2003 Share Posted October 17, 2003 You can get one from a junk yard, or get one from the dealer for about $17, and change the guts out with yours..... GD Link to comment Share on other sites More sharing options...
sidekickin Posted October 18, 2003 Author Share Posted October 18, 2003 From the southwest part of the state....Hamilton, Ohio. My first car was an '80 GL 4WD wagon with the infamous 3rd headlight. I always thought that was the coolest thing. Drove that car for 5 years until I was 21 and some lady rear ended it and destroyed it. I was crushed. Last year I acquired the '87 STD 4WD Hatchback. Absolutely love it, but not as much as the '80 GL since the '87 it lacks a lot of the neat features of the '80 GL. I was always a big fan of the full set of gauges on the GLs. Wish I had access to an old GL so I could swap the dashboards. But around here most of the '80-'84 bodystyle Subarus are gone. By far my favorite bodystyle....and that durable, reliable motor with no timing belt. Gotta love that. It still amazes me that Subaru would go to a timing belt design with the EA82 just for a very modest increase in HP over the EA81. _______________ 1987 STD 4WD Hatchback w/ hydraulic lifters and S/R 4WD Link to comment Share on other sites More sharing options...
AKIRA Posted October 18, 2003 Share Posted October 18, 2003 It's the infamous 5th headlight for me:D Link to comment Share on other sites More sharing options...
GeneralDisorder Posted October 18, 2003 Share Posted October 18, 2003 You *could* swap out the dash, but it would be a LOT of work. The wiring harness is different, and you would have to swap all the idiot light switches under the hood for the correct sending units for the guages. Not as easy as just swapping the dash. Actually - I kind of like the DL setup myself. It was very simple, but I like simple..... GD Link to comment Share on other sites More sharing options...
roosofallevil Posted October 20, 2003 Share Posted October 20, 2003 If you miss your 80 3 eyed hatch that much you can offer me massive amounts of money for mine. Wish you had spoken earlier I just added a long push bar and 6 driving lights tonight its now a 9 eyed beast. roosofallevil:banana: Link to comment Share on other sites More sharing options...
sidekickin Posted October 20, 2003 Author Share Posted October 20, 2003 Well, guys, the job is completed....at least temporarily. Didn't have the time to do it real well, so I rigged up a solution and it worked really good. First, I disconnected the rubber hoses for the ASVs where they connect to the air cleaner assembly. Then I cut out small pieces of aluminum from a pop can and covered the metal "male" end on the air cleaner side with the piece of aluminum and then reconnected the rubber hoses with the aluminum piece inside. This way it blocks the flow of exhaust gas from the bad ASV. My car has 2 ASVs, so I did this with the other side as well (even though it wasn't bad yet). At least by doing that it will prevent any plastic pieces of the ASV from getting sucked into the carburetor when it does decide to go bad. Anyway, after doing this I fired the car up and it was whisper quiet. No rumbly exhaust noise or anything. When I do have time I may do a more permanent solution such as buying a new ASV or removing the entire Air Injection system from the car. But for now this will work. Thanks everybody for your help!!! Billy ____________ 1987 STD 4WD Hatchback EA81 w/hydraulic lifters and S/R 4WD Link to comment Share on other sites More sharing options...
GeneralDisorder Posted October 20, 2003 Share Posted October 20, 2003 One thing many of us have done, is to put some wire screen over the intake for the carb, so that peices of plastic can't get in. This has the added benifit that youcan leave it in place in case you ever blow one up in the future. GD Link to comment Share on other sites More sharing options...
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