Odd Compression Issue

[Flyerborn]

Hi everybody, this is my first post and I apologize if this scenario has been talked about before but for the life of me I cannot find anything in the search option.. 

 

Anyways! 

I bought an 82 Subaru GL Wagon for $200 not too long ago that had been sitting for a while because somebody couldnt figure out why it wouldn't turn over. Assuming it's got an EA81 in it? Fixed the fusible link issue, had to bypass the Fuel Pump Control computer, and finally got the thing to crank over with constant fuel delivery. Only, when it does, it tends to backfire through the carb once per crank attempt. No big deal, probably needs a carb rebuild. Pull off the carburetor and while I'm at it, decided to pull the plugs and do a compression test to check the overall health of the engine. Primed the cylinders with a little oil, and on the passenger side I get a consistent 180psi (cyl. 1) and 175psi (cyl. 3), but on the driver's side I get a big fat 0.. For both cylinders... Seems very odd to me that 2 cylinders would push absolutely no compression at all unless maybe a valve was hung open? Perhaps that's why it backfires through the carb and the plugs are wet?? At this point I haven't had time to remove the valve cover and check the valve train, but as this is my very first Soobie ever, I wanted to consult some of the experts before diving too deeply into this engine. I'm totally fine with having to rebuild the engine if that's the case, but I would rather not if I can help it, so are there any common symptoms with these that I should check for first? My only other speculation would be the possibility of a blown head gasket, but before I went that far I wanted to ask. 

 

Many thanks in advance!

Edited April 8, 2018 by Flyerborn

[Sapper 157]

If its an 82 then yes, you have an EA81. First thing that comes to mind is that the valves are indeed stuck open.

[Flyerborn]

Okay. I might as well pull the cover and check. Is there a factory spec valve clearance to go off of for these engines? Are they solid lifter cams? Or hydraulic? I'm not new to working on and rebuilding vehicles, but I'm definitely new to these subaru engines, so please pardon my noob questions. I try to do research where I can, but sometimes it's much more helpful to just ask.

 

As for the needle moving. As far as I can tell, the needle doesn't move at all. Literally 0 psi. If there was something like 40-50 or something like that I'd lean towards a head gasket more, but zero seems like a rather large leak..

Edited April 8, 2018 by Flyerborn

[Flyerborn]

Well would you look at that! I havent noticed any sort of sticker on mine, but is there any telltale sign to look for on these engines to differentiate the two? I'll double check if I have a little gold sticker, but if not, I suppose all I can do it rotate the engine by hand and see if I see the valves move and the pushrods go from tight to spinning with my fingers?

[DaveT]

I doubt that the valve adjusters have enough range to get the compression to zero. Pull the cover, see if the valves are stuck.

[GeneralDisorder]

Backfiring out the carb is a sign of combustion taking place on an open intake valve. Likely to be valve problems.

 

82 does not have hydraulic lifters. And in any case they get loose not tight as their pressure bleeds down.

 

GD

Edited April 8, 2018 by GeneralDisorder

[Flyerborn]

Going out to check on it now. If the valve is indeed stuck, is there anything I can really do about it to get them unstuck? Seems like if they're stuck that may be a valve guide issue that'd require a head rebuild anyway. Are these engine interference engines? Could the valves possibly be bent by the pistons if they get stuck open? If so, where would I get new pistons and valves. A quick search on rockauto and summit racing really doesn't show me a long list of available parts for these things...

[GeneralDisorder]

They are not interference. You can't get valves for them anymore. Not even from Subaru. Very few parts are available in general for EA series cars other than from the junk yard. A customer of mine has gone through 6 used engines trying to find a viable bottom end, etc. So far his car still isn't on the road.

 

GD

[Flyerborn]

A viable bottom end? Oh boy. Makes me worry about this one a little bit. What's wrong with their bottom ends? As for valves, is it possible to get similar sized valves and machine down their stem to the desired installed height or is that more work than its worth? I'm trying to avoid swapping this engine as I'm trying to keep the build as inexpensive as possible (willing to spend where required of course) but if the EA81 won't be possible to repair I may need to think of other options for an AWD powertrain.

[GeneralDisorder]

Usually it's cylinder wall issues from sitting. The bottom ends are pretty good but all the used stuff out there has sat and got water in the cylinders rendering them useless without a rebuild which is not viable from an economy or parts standpoint.

 

My guess, based on decades of experience with these, is that you will find a rusty mess in those two cylinders and the valves are rusted to the guides. Very unlikely any of it will be salvageable. The intake gaskets fail and dump coolant (or whatever was in there) into the intake, and down the cylinders through any open valves.

 

GD

Edited April 8, 2018 by GeneralDisorder

[Flyerborn]

Okay. Updated progress report:

 

Adjusted the valves (int. .010 & exh. .014) and I've got compression now! 90psi in cylinder 4 and 110psi in cylinder 2. Both considerably lower than the passenger side but much more progress than I had expected. Now what do you guys think?

 

Both intake and exhaust valves were being stuck open which seem to move fairly fluidly. Surprisingly no rust under the valve covers that I could spot and a quick glance with a bright light in the spark plug holes reveal a shiny surface as I turn this little thing over by hand. Trying to be as realistic as possible in this scenario, but at this point, im leaning somewhat towards a head gasket. The oil in the pan and stick is very clean, but inside the valve cover I see a milky substance possibly that had been sitting from before. I know at one point the passenger side head gasket had blown, but what are the chances both blew simultaneously?

[DaveT]

At this point, start it see if it will run.

 

Most common way headgaskets fail on these causes combustion gasses to escape into the cooling system. Look for bubbles in the radiator / recovery tank.

 

If it runs, monitor coolant closely. See how it goes, recheck compression. Monitor coolant system closely.

[GeneralDisorder]

If the valves had no clearance I would be guessing burnt exhaust valve(s). 90 psi is very low. Might come up after running though. Make sure its getting oil pressure and run it.

 

GD

[Flyerborn]

Okay, so another quick update. Set valve lash on both sides of the engine and put the carburetor back on before rebuilding it just to see what would happen. Hot-wired the fuel pump and cranked it over. After letting the fuel system prime for roughly 5 seconds I hit the starter and about 2 cranks in it fired right up, but idle was super low and oil pressure rose to damn near 70psi... Adjusted the timing and now it seems to idle surprisingly smooth at a steady 900rpm for not having been run in several years. Unfortunately there is a massive exhaust leak so it's hard to listen closely for a misfire, but there was no apparent miss or vibrating of the engine. Held a relatively clean idle and throttle response really was *much* better than I had expected. 

 

When I got it, the radiator was half way full and I thought immediately that was a sign of a leak somewhere internally on the engine from sitting so long, but upon filling the coolant I found the hole in the upper radiator hose very quickly, and now the coolant seems steady. No bubbling yet, but I haven't run it long enough I don't believe. I stopped it because I was monitoring the oil closely and noticed it get milky immediately, but I suspected that would be the case since it had gotten milky under the valve covers and I think it might've just washed down into the pan. So, before I start it again I plan on changing the oil and filter.

 

Initial thoughts from everyone? I just cant believe it started, let alone idle right off the bat at a steady 900rpms. Seems maybe a tad high, but when I let out the clutch it appears to drop to around 700. Should I change the oil, run it up to temperature and do another compression check?

 

 

Side note: 

Does the starter not disengage until it detects voltage or something because when the engine wont start and I try to crank it over it gets hung up, but when it actually does start, the starter disengages immediately.... ?

[DaveT]

The starter has no fancy controls.  IF you turn the key, it should crank.  It will crank until the battery is discharged or the starter burns out.

 

Once you have the coolant system filled, moderately blown head gaskets will cause bubbles almost immediately.  If they are at the very early stage, you have to wait until everything is stabilized, and several closely monitored drives.

[GeneralDisorder]

Carbs idle high when cold. This is normal. Its called a fast idle cam. Usually there are two steps above base idle depending on temp. This is one reason you "set" the choke with at least one accelerator pedal pump prior to cold start. This sets the choke, pulls in the fast idle cam, and primes the venturi with an accelerator pump shot for quick, efficient starting.

 

Milky substance is from crankcase vents - condensation and short run times do this. Its normal.

 

Starters can get stuck partially engaged if the engine doesn't catch. The action of the engine turning faster than the pinion sucks the bendix back into the starter. This is usually not an issue in practice. Lubrication of the starter bendix, reduction gearing, etc is likely needed or perhaps starter replacement.

 

70+ psi oil pressure is normal for these engines when cold. We *like* to see at least 15-20 psi at idle when up to temp. It should climb to 40+ under acceleration. The factory gauge is NOT to be trusted. They can read high, or low, or not at all. The gauge is way out of calibration at this point and the sending units are a common failure item.

 

GD

[Sapper 157]

You might consider doing a quick oil change with some cheaper oil mixed with a few cups of MMO or Seafoam in with your fresh oil. Then do another oil change after a thousand miles or so... It should help clean some stuff out. Also wouldnt hurt to run a can of seafoam through your fuel system with some fresh gas (although maybe you already put fresh gas in and I just missed that??)

Edited April 9, 2018 by Sapper 157

[Flyerborn]

I have a bit of an update but I really haven't had too much time to work on it as of late. I believe the car must've been sitting for at least a few years, but I could be wrong. I came across it's craigslist add from a guy that owned a wrecking yard who traded it for a 50cc dirt bike a year or so ago, and it sat before that point as well.. It's got 236K miles on it but it still seems to start up and run like a champ. Obvious tweaking will be needed, but overall, I'm very lucky. It idles and throttle response is surprisingly crisp considering I'm used to my 347 with a big Holly DP in the Maverick that usually takes the Sooby's spot in the garage. 

 

I changed the oil, and it got milky almost immediately again, but the coolant level hasn't changed or bubbled so I believe I may need to flush the oil once or twice more to get all of the condensation out of the crankcase. That's more of a time consuming task than anything else and I just haven't had the time to run to the store and pick up oil for it. Otherwise the car seems to run pretty damn good for the most part. Unfortunately I've taken the suspension pretty much all apart so going for a short drive is a little out of the question at the moment since it's going to become somewhat of a Frankenstein lift conversion soon. But it appears the transmission shifts through the gears fairly well and all the ranges work as they should. Even the range selectors in the dash light up accordingly. I'm quite surprised with how much on this car still works despite it's condition. Once I get more time to work on the engine and get it up to running temp I'll have more of an update for everyone. As for how it sits currently I don't want to run it extensively due to the fact that I have no real way of knowing reliably that it has sustainable oil pressure. Or at least until I can guarantee that coolant is not fouling the oil and that all the current milky substance it out of the crankcase.

 

BTW: Any tips for completely draining and flushing the oil pan during oil changes? Seems like there's still just a small amount of oil that sits in the pan after it stops draining. Seems like these engines tend to hold oil in a few places throughout them instead of all draining back to the pan?

Edited April 11, 2018 by Flyerborn

[Sapper 157]

 

BTW: Any tips for completely draining and flushing the oil pan during oil changes? Seems like there's still just a small amount of oil that sits in the pan after it stops draining. Seems like these engines tend to hold oil in a few places throughout them instead of all draining back to the pan?

Yeah the pan is easy to remove, and most people just replace he gasket with RTV. Real simple job. Just be sure the mating surfaces are extra clean when you put them back together and don’t overtorque the pan bolts. Also tighten in criss cross pattern I think they only have like a 3.5 - 5 ft lbs torque iirc Edited April 11, 2018 by Sapper 157