2.2 lost compression 50% overnight

[Brentm1911]

Greetings to the new forum

 

1995 legacy ej22, 133,000 miles, purchased 5 yrs ago, wifes daily driver, 20,000 miles since purchase.

Never had any check engine issues.

95 with an OBD2 output.

 

Had a CEL, check code, PO125. Check coolant levels, OK.

Cleared codes.Restart 2 times and ran 20 minutes each with no new codes.

 

Next morning car will not start.

 

I have fuel, air, spark. Timing of SOHC cams and crank reluctor line up. Timing space 44 left, 40.5 correct. Crank key not sheared, hydraulic adjuster works fine.

 

Compression on all 4 cylinders around 80 psi, 50% low.

 

Bore scope inspection with Snap on camera shows nice cross hatch in all cylinders.

 

Does anyone have any great ideas?

 

Thank you in advance.

 

 

[1 Lucky Texan]

kinda wondering about flooded engine. Cylinder 'wash down' can lower compression.

 

maybe try holding the gas pedal down while starting. That triggers 'clear flood' mode on the ECU.

 

If the engine temp sensor is always telling the ecu the car is cold - the ecu opens the injectors and 'chokes' the engine with more fuel.

 

On some older soobs there are 2 temp sensors, the 2 wire unit is for the ecu. On newer soobs there is a single 3 wire unit for the temp gauge and the ecu.

[1997reduxe]

wow people here know everything.

[1997reduxe]

have you changed the gas filter ever?

[1 Lucky Texan]

lol! - I'm wrong a LOT, just throwing out ideas - mostly based on reading.

 

plus - always try the easy stuff first.

 

It's hard helping folks over keyboard communication. They don't give you all the info, you're not there to experience the problem in person - smell the smell or hear the noises or feel the vibrations, just making educated guesses.

 

we are lucky to have experienced folks here and they will chime in, especially if they think I'm off-base.

Edited December 15, 2016 by 1 Lucky Texan

[montana tom]

Car was running fine, then cel came on and car continued to run OK ? Low coolant code. Was coolant low ? You clear the code , run it twenty minutes , shut it down ,restart same thing , all good ...go to bed .  Next morning normal routine and car cranks but will not fire ?  Did you try to the hold the pedal to the floor ? Not all subi's that are 21 years old will have 160 psi but 80 is unacceptable. At 80 psi your wife would have come home and said it had no power. Sounds like to me like Texan  is on the right track , fuel is washing your cylinders  . Check your oil ... is it overfull ? Smell like gas ?  I think your year has 2 separate sending units ,a one wire for the dash and a 2 wire for comp. The 2 wire could be sending faulty signals to the computer. 

[idosubaru]

You obviously know what you're doing so pardon the simplicity here but it's just trickier using a keyboard than in person or seeing the vehicle. 

 

I'm going to guess that P0125 is really a P0325 knock sensor code - can you verify that code for us?

 

All 4 cylinders having the same low value suggests it has to be something affecting the entire engine - the only thing I can think of right now are air supply, timing, and RPM's:

 

A weak battery or slowly turning over will reduce compression, it is directly related to RPM's - though I'd suspect you would recognize that?

 

Pull the intake manifold and prop the throttle plate open to make sure it's getting sufficient air flow or just check the air hose and make sure no rodents built a nest in there. 

 

Triple check that timing and make sure you're looking at the proper timing marks, that's a common mistae. 

[Fairtax4me]

Need to squirt some engine oil into the cylinders and see if the compression comes up. Good chance that ECT sensor is bad and it's dumping fuel in and washing the cylinders down.

 

Also, were those compression numbers done with the throttle wide open? Intake in removed?

Did you check the intake tube and air filter for a mouse nest or squirrel stashing acorns in there?

[1 Lucky Texan]

also, there can be pending codes before the CEL is set - you might scan it again.

[1997reduxe]

btw to just throw out ideas you have to have them first.

[Brentm1911]

Thanks for all the great ideas and keep them coming. I will tackle the beast this weekend when I get back home and hopefully have some good news.

 

But to answer some questions.

 

1. Timing marks on belt gone but tooth count left and right of crank to cam pulleys correct.

 

2. No rodents, nests or wookies in the intake.

 

3. Compression test done with throttle plate closed and 24 hr charge on 2 yr old battery. Retest and try the motor oil trick.

 

5. Oil level does seem high and a little things. Leaks a little around valve cover and usually needed a quart between changes. Change oil before next test.

 

6. What gas filter? Lol. But no I have not.

[Brentm1911]

5. Oil level a little high and seems think.

 

Sorry, auto correct.

[Fairtax4me]

Compression test should be done with throttle held wide open. All four spark plugs out at same time. Put your foot on the floor and hold it down when cranking. I usually go 5 puffs then stop.

 

Closed throttle the engine will build vacuum in the intake and will show low compression because its struggling to get air in.

[1997reduxe]

the gas filter is inline of the gas line inside the hood i forget where i think its toward the rear on the wall? someone here can verify or look at chiltons manual. its a little canister with line in and out. in my experience and reading here what happens (i used to be the maintenance worst, i blamed it on the alcohol, not now )

is that the filter fills up and up with dirt if you never changed it maybe someone owned it before and they didnt either? so its full of ten twenty years of dirt? well these cars can limp along on nothing, little voltage, battery that wouldnt run a flashlight, little gas, till that one last piece of dirt from the tank fills the last speck hole.

i would change it regardless.

Edited December 16, 2016 by 1997reduxe

[idosubaru]

Yeah you're on it, the belt marks are pointless, just a needless aid. The timing marks on the crank and cam pulleys have to be spot on.

 

Make sure timing tensioner isn't loose and deflecting while under load. Ive seen it before but they've always started and ran and deflect while starting or accelerating. cant imagine this being the case here but easy check

 

Can you do a leak down test?

 

I've done it before but have never diagnosed anything adding oil in the cylinder. Being horizontal the oil is going to lay in the bottom of the cylinder and only a small percentage of the rings - does that matter?

 

it would be good to replace the filter. But it would also be good to replace other things as well. He said he has fuel and fuel filter can't cause compression loss.

 

Subarus rarely have fuel filter issues so check the post filter flow and call it good. the pumps have socks (filters). If fuel filters commonly were plugged that amount of debris would have to make it past those socks first to get to the fuel filter. so those fuel pump socks would clog too - presumably first if there's an outlier environmental factor causing abnormal particulate build up in the tank. but they rarely do, I've never seen a clogged fuel filter and many diagnoses are dubious, so it's highly unlikely except for rusty fuel tanks which doesn't seem to be the case here.

[1997reduxe]

did yo ever figure it out? i ooked up the coolant code it weemed it wouldnt heat up fast enough i saw this old one:
http://www.ultimatesubaru.org/forum/topic/140608-p0125-p0325-p0115-starting-issue-and-more-in-a-95-subaru-legacy/

[john in KY]

Sniff the oil. Does it have a gasoline smell? Pull the vacuum line at the FPR and see if the FPR has ruptured. 

[CNY_Dave]

5. Oil level a little high and seems think.

 

Sorry, auto correct.

 

Sounds like could be gas in it.

[nipper]

Sudden loss of compression after shutting the car off is usually a timing belt. The belt unloads develops some slack then jumps. Any idea on how old the timing belt is. Never go by the marks on the belts, they are handy but only the timing marks on the crank cam can tell for sure.

[Brentm1911]

Christmas Greetings to all. Looks like the problem is the ECTS. Following all your thoughts I shot some oil in the cylinders to help the rings, tried to start normal, no joy. Held throttle WFO and she started in a cloud of smoke. Settled down to a steady purr.

 

Ran for 15 minutes and temperature gauge never moved but the thermostat opened. On last run before no start condition the temperature gauge worked.

 

ETCS is in hand and waiting for Saturday to install.

 

Thank you everyone for all the information and especially 1997Redux for the link to an old post that was spot on for this issue.