1996 Legacy EJ22 engine problem: catalytic, Woodruff key, cr
Posted: Mon Jul 31, 2006 5:41 am
I bought a 1996 Subaru Legacy AT AWD Brighton (base model) SW with an EJ22 4 cylinder 2.2 liter engine and 14 inch running gear with 150K miles on it. Compression check found all cylinders 182-190 psi and it passed the emissions check with new catalytic converters.
I love the design simplicity, ease of maintenance, and reliability, and especially that it gets 30mpg at 75mph on the highway. Unfortunately, however, I have some engine problems that may be a “learning experience” for me.
___
I: Catalytic Converter:
I had an aftermarket catalytic converter (Eastern) put in it because the old one had rusted out. Installation mechanic put the forward O2 sensor in the port on the rear of the forward catalytic converter, and it promptly coded slow O2 sensor—not surprisingly. I moved it to where it was supposed to be—forward of the forward catalytic converter, which places the wires within 1/4 inch of the rotating right front drive axle shaft. I adjusted the converter pipe down on the manifold as much as possible to maximize the clearance. I then took it back to the mechanic to clear the code.
Well, I have driven it maybe 5000 miles, and my new cheap generic OBD-II scantool says that that there are no hard codes, and “MIL = on”, but the check engine light (CEL) on the dash is off, and the status of the Cat, O2S, HO2S, and EGR are all “Not Ready”. He musta done something! I have not found any plugs pulled (are they all on a single connector somewhere in the harness, e.g. at the firewall?), wires clipped (the Chilton’s engine control wiring diagram suggests that the Ye/R wire on the main relay runs the O2Ss, IAC, EGR, purge and “pressure sources sw sol valve”—does anyone know where the relay is?), and I do not know about any bypass jumper (the green “test mode” connector under the dash is unplugged).
Any ideas as to what to look for? I plan to find why all the emissions sensors are offline, then turn them online, then see what codes come up, and then fix the original problem.
___
II: Crank Pulley, Woodruff Key, and Valve Timing:
When I got the car I turned on the AC and somehow heard a noise I discovered that the crank pulley bolt was loose and the pulley was beginning to saw against the Woodruff key. Likely whoever had replaced the timing belt had not tightened the bolt enough. I replaced the oil pump (there was an oil leak), water pump, timing belt, Woodruff key, and crank pulley.
Unfortunately, I did not know that there is a special tool with 4 pins to hold the crank pulley solid while tightening the shaft bolt, or that you can use a chain pipe wrench around the pulley, or that you can have a friend jam a pry bar into the ring gear through the inspection hole on top of the back of the engine, but it is rumored that you need about 100-130 foot pounds of leverage on the bolt to tighten it, plus maybe thread locker. For discussion, see:
Marinucci, Dan: “Foreign service”, Motor July-Sept 2001.
http://findarticles.com/p/articles/mi_q ... i_n8959141
http://findarticles.com/p/articles/mi_q ... i_n8971906
http://findarticles.com/p/articles/mi_q ... i_n8969972
and a “must read” on crank pulleys at bbs.legacycentral.org .
I drove it about 2000 miles, and the new pulley slot wore on the Woodruff key completely around the circumference, then spun loose on the shaft and threw the belts. I had major concerns about shaft end and Woodruff key slot wear, but as I was away from home I pulled the timing belt in a parking lot and replaced the key and pulley (I think that key insertion requires pulling the timing belt and crank drive sprocket—I cannot see how to insert the key into the slot while the crank drive sprocket is on) and drove it to a dealer on battery without belts and told them to tighten it down as hard as they could to get me home, and decided to never fix the AC so as to reduce pulley load on the worn shaft.
I would not be surprised, however, if the valve train cam was retarded a few degrees from the crank timing due to Woodruff key slot wear which might have allowed the key to angle sideways a bit. (I started the engine before I put the pulley on, and noticed a bit of a idle-rpm clatter which went away at high rpm that I suspected might be the Woodruff key rattling as the cam load varies on the crank as the engine fires and turns.) I hoped that the key issue was not relevant, because I interpreted the design as having the crank pulley bolt press against the crank pulley against the timing belt drive pulley against a shoulder on the crankshaft, to hold it solid by pressure fit, while the Woodruff key keeps it generally aligned. I hoped it would not wear or change timing as long as the pulley was bolted down solid, but the crank does get hammered on every piston firing.
___
III. Current Power Problem:
Shortly after I had the crank pulley bolted down due to the Woodruff key problem, the engine developed a power problem, which is the present issue. Notably, the check-engine light has not come on, but I figure that the catalytic converter mechanic may have done something to block coding of emissions problems, and apparently non-coding is common with Woodruff key valve timing problems.
A) Symptoms: The 1996 Legacy EJ22 runs in one of three states:
1) near-normal: at 75 up to mph with 28+ mpg.
2) moderate problem: Usually on a hot day after it has been driven a while, it does not want to run over 40 mph, it has no “vacuum advance” perk, it easily kicks down the transmission (low manifold vacuum?), pushing down the throttle just makes exhaust muffler noise, and full throttle causes a misfire but little acceleration. It does not want to go uphill. It drives fastest on a downhill run at minimum throttle at night (cooler).
3) major problem: Usually on a hot day after it has been driven a while, it does not want to run over 15 mph, there is a hum from the driver’s side valve train (flat/boxer/pancake 4 cylinder engine), and, if driven faster, an EGR control “vacuum” hose blows off and whistles, first fast and furious and then slower, releasing what I presume is exhaust back pressure (but I supposed it could be something else, like leakage from a cracked head). [It is the vacuum hose that goes from near the intake manifold end of the EGR tube to the bottom of the round plastic disk vacuum control unit above the EGR valve located to the driver’s side of the throttle valve. On top the disk has two vacuum hoses that go to the throttle valve, and one that goes to the EGR solenoid and then on to the EGR servo diaphragm. I figure that it might be some sort of exhaust backpressure modulator on the EGR valve control circuit.]
Notably, using “valve medic” in the oil (napthylated hydrocarbons) seems to reduce the severity of the problem for the next hundred or so miles.
The car seems to drive okay with the green “test mode” connector plugged in, but I it does not seem to cure the problem, at least not once it has begun acting up. Pulling the Throttle Position Sensor also does not seem to cure it.
Any suggestions? I suspect that the EGR hose blowing off and whistling when it gets hot may be a big hint as to what is going on. It may not be the only problem, though, like there may be a bit of a timing problem and a bit of an emmissions sensor problem, etc.
Hypotheses (My Guesses):
1. Woodruff key slot damage: Maybe the valves are now timed a few degrees late do to widening of the Woodruff key slot. This may result in overheating of something in the Driver’s side head. The “naptha” in “valve medic” vaporizing through the PCV system improves the octane for faster burn and may reduce the timing problem. Action: I don’t know a MIG welder, don’t do braizing, don’t know where to buy a wider Woodruff key (auto parts or hardware store?), do not have much metalworking experience (e.g. to reform the slot, drill a “Dutchman” pin between the shaft and pulley, or drill at an angle into and pin the shaft), and the engine has 150K miles on it, so disassemble timing belt, clean and use “quickmetal”, “sleave retainer” and “thread locker” on the crank, key, sprocket, pulley, and bolt to glue it together, use 24 inch chain pipe wrench and breaker bar to tighten over 100 ft-lbs and hope that the bold does not snap (replace the bolt?), and hope the fix it holds till the engine dies. Notably, the key is under significant stress each time the engine fires, so the fix must be solid. Opinion: difficult to do with unpredictable results, and possibly unnecessary, so try everything else first. Also, it is an irreversible fix, so it would be useful to know first if there was a head problem.
There is one other suggestion I like, linked to in the “must read” on crank pulleys at bbs.legacycentral.com, and that is to drill 2 holes through the new crank pulley and bolt it into the existing 2 holes in the crank sprocket tapped 5/16x18x 1/2 in. The idea is that if the crank pulley and crank sprocket are bolted together so that they cannot shift with respect to eachother, a new Woodruff key is likely to be held square (even by the soft pulley metal) and is much less likely turn, shift, and wear on the crank.
2. Catalytic converter: Apparently the mechanic wired-out the emission sensors about 6000 miles ago, and maybe it is coming back to haunt me with a backpressure problem, maybe due to chronic low O2 in the catalytic converter. (It got 30mpg much of the time.) Opinion: A fix is probably necessary anyway, but may not be possible to diagnose if there is a mechanical problem such as a valve or timing problem.
3. Timing belt: I think that I got it right, and both cam pulleys match, but I cannot pull the central cover off until I tear it down again. Same as above explanation on “valve medic” and octane. Same as above action on Woodruff key damage.
4. Unidentified Sensor failure: Throttle position sensor failure, resulting in bad fuel mix when throttle is opened? Pulling the plug did not seem to help. O2 sensor failure (is it even working if the OBD-II says “not ready”?) somehow causing too much back pressure in the exhaust system? EGR control (it sometimes opens at high rpms if the throttle is opened slowly and evenly, but usually it starts to move but then closes after a half second)? Action: Pull all sensors but crank, cam, and MAP and drive carefully, to see if the problem goes away. If so, then plug sensors back in one at a time. (Problem: many of the emissions sensors are in “not ready” mode and may already not be working.) Opinion: sounds simple enough, and it may reduce the number of variables in the system.
5. Valves: Maybe there is a sticking valve, which gets worse when the engine is hot, and screws up the emissions, and maybe “valve medic” loosens it. (Note, the 1996 EJ22 is reputedly a noninterference engine, so a timing problem will not directly result in a bent valve, and the compression check was good.) Action: If a bad valve can be demonstrated, then swap in a cheap junk-yard engine, and keep the spare parts. Opinion: I am not really set up to pull an engine, although I hear that it is far easier with a light high-mounted Subaru boxster than with deep, heavy Detroit V-8s.
Is pulling the spark plug while the engine is running and acting up a good way to identify a valve problem when the compression is okay? Will the spark plug packs tolerate a pulled wire?
Any suggestions as to where to start???
Thanks in advance!!!
I love the design simplicity, ease of maintenance, and reliability, and especially that it gets 30mpg at 75mph on the highway. Unfortunately, however, I have some engine problems that may be a “learning experience” for me.
___
I: Catalytic Converter:
I had an aftermarket catalytic converter (Eastern) put in it because the old one had rusted out. Installation mechanic put the forward O2 sensor in the port on the rear of the forward catalytic converter, and it promptly coded slow O2 sensor—not surprisingly. I moved it to where it was supposed to be—forward of the forward catalytic converter, which places the wires within 1/4 inch of the rotating right front drive axle shaft. I adjusted the converter pipe down on the manifold as much as possible to maximize the clearance. I then took it back to the mechanic to clear the code.
Well, I have driven it maybe 5000 miles, and my new cheap generic OBD-II scantool says that that there are no hard codes, and “MIL = on”, but the check engine light (CEL) on the dash is off, and the status of the Cat, O2S, HO2S, and EGR are all “Not Ready”. He musta done something! I have not found any plugs pulled (are they all on a single connector somewhere in the harness, e.g. at the firewall?), wires clipped (the Chilton’s engine control wiring diagram suggests that the Ye/R wire on the main relay runs the O2Ss, IAC, EGR, purge and “pressure sources sw sol valve”—does anyone know where the relay is?), and I do not know about any bypass jumper (the green “test mode” connector under the dash is unplugged).
Any ideas as to what to look for? I plan to find why all the emissions sensors are offline, then turn them online, then see what codes come up, and then fix the original problem.
___
II: Crank Pulley, Woodruff Key, and Valve Timing:
When I got the car I turned on the AC and somehow heard a noise I discovered that the crank pulley bolt was loose and the pulley was beginning to saw against the Woodruff key. Likely whoever had replaced the timing belt had not tightened the bolt enough. I replaced the oil pump (there was an oil leak), water pump, timing belt, Woodruff key, and crank pulley.
Unfortunately, I did not know that there is a special tool with 4 pins to hold the crank pulley solid while tightening the shaft bolt, or that you can use a chain pipe wrench around the pulley, or that you can have a friend jam a pry bar into the ring gear through the inspection hole on top of the back of the engine, but it is rumored that you need about 100-130 foot pounds of leverage on the bolt to tighten it, plus maybe thread locker. For discussion, see:
Marinucci, Dan: “Foreign service”, Motor July-Sept 2001.
http://findarticles.com/p/articles/mi_q ... i_n8959141
http://findarticles.com/p/articles/mi_q ... i_n8971906
http://findarticles.com/p/articles/mi_q ... i_n8969972
and a “must read” on crank pulleys at bbs.legacycentral.org .
I drove it about 2000 miles, and the new pulley slot wore on the Woodruff key completely around the circumference, then spun loose on the shaft and threw the belts. I had major concerns about shaft end and Woodruff key slot wear, but as I was away from home I pulled the timing belt in a parking lot and replaced the key and pulley (I think that key insertion requires pulling the timing belt and crank drive sprocket—I cannot see how to insert the key into the slot while the crank drive sprocket is on) and drove it to a dealer on battery without belts and told them to tighten it down as hard as they could to get me home, and decided to never fix the AC so as to reduce pulley load on the worn shaft.
I would not be surprised, however, if the valve train cam was retarded a few degrees from the crank timing due to Woodruff key slot wear which might have allowed the key to angle sideways a bit. (I started the engine before I put the pulley on, and noticed a bit of a idle-rpm clatter which went away at high rpm that I suspected might be the Woodruff key rattling as the cam load varies on the crank as the engine fires and turns.) I hoped that the key issue was not relevant, because I interpreted the design as having the crank pulley bolt press against the crank pulley against the timing belt drive pulley against a shoulder on the crankshaft, to hold it solid by pressure fit, while the Woodruff key keeps it generally aligned. I hoped it would not wear or change timing as long as the pulley was bolted down solid, but the crank does get hammered on every piston firing.
___
III. Current Power Problem:
Shortly after I had the crank pulley bolted down due to the Woodruff key problem, the engine developed a power problem, which is the present issue. Notably, the check-engine light has not come on, but I figure that the catalytic converter mechanic may have done something to block coding of emissions problems, and apparently non-coding is common with Woodruff key valve timing problems.
A) Symptoms: The 1996 Legacy EJ22 runs in one of three states:
1) near-normal: at 75 up to mph with 28+ mpg.
2) moderate problem: Usually on a hot day after it has been driven a while, it does not want to run over 40 mph, it has no “vacuum advance” perk, it easily kicks down the transmission (low manifold vacuum?), pushing down the throttle just makes exhaust muffler noise, and full throttle causes a misfire but little acceleration. It does not want to go uphill. It drives fastest on a downhill run at minimum throttle at night (cooler).
3) major problem: Usually on a hot day after it has been driven a while, it does not want to run over 15 mph, there is a hum from the driver’s side valve train (flat/boxer/pancake 4 cylinder engine), and, if driven faster, an EGR control “vacuum” hose blows off and whistles, first fast and furious and then slower, releasing what I presume is exhaust back pressure (but I supposed it could be something else, like leakage from a cracked head). [It is the vacuum hose that goes from near the intake manifold end of the EGR tube to the bottom of the round plastic disk vacuum control unit above the EGR valve located to the driver’s side of the throttle valve. On top the disk has two vacuum hoses that go to the throttle valve, and one that goes to the EGR solenoid and then on to the EGR servo diaphragm. I figure that it might be some sort of exhaust backpressure modulator on the EGR valve control circuit.]
Notably, using “valve medic” in the oil (napthylated hydrocarbons) seems to reduce the severity of the problem for the next hundred or so miles.
The car seems to drive okay with the green “test mode” connector plugged in, but I it does not seem to cure the problem, at least not once it has begun acting up. Pulling the Throttle Position Sensor also does not seem to cure it.
Any suggestions? I suspect that the EGR hose blowing off and whistling when it gets hot may be a big hint as to what is going on. It may not be the only problem, though, like there may be a bit of a timing problem and a bit of an emmissions sensor problem, etc.
Hypotheses (My Guesses):
1. Woodruff key slot damage: Maybe the valves are now timed a few degrees late do to widening of the Woodruff key slot. This may result in overheating of something in the Driver’s side head. The “naptha” in “valve medic” vaporizing through the PCV system improves the octane for faster burn and may reduce the timing problem. Action: I don’t know a MIG welder, don’t do braizing, don’t know where to buy a wider Woodruff key (auto parts or hardware store?), do not have much metalworking experience (e.g. to reform the slot, drill a “Dutchman” pin between the shaft and pulley, or drill at an angle into and pin the shaft), and the engine has 150K miles on it, so disassemble timing belt, clean and use “quickmetal”, “sleave retainer” and “thread locker” on the crank, key, sprocket, pulley, and bolt to glue it together, use 24 inch chain pipe wrench and breaker bar to tighten over 100 ft-lbs and hope that the bold does not snap (replace the bolt?), and hope the fix it holds till the engine dies. Notably, the key is under significant stress each time the engine fires, so the fix must be solid. Opinion: difficult to do with unpredictable results, and possibly unnecessary, so try everything else first. Also, it is an irreversible fix, so it would be useful to know first if there was a head problem.
There is one other suggestion I like, linked to in the “must read” on crank pulleys at bbs.legacycentral.com, and that is to drill 2 holes through the new crank pulley and bolt it into the existing 2 holes in the crank sprocket tapped 5/16x18x 1/2 in. The idea is that if the crank pulley and crank sprocket are bolted together so that they cannot shift with respect to eachother, a new Woodruff key is likely to be held square (even by the soft pulley metal) and is much less likely turn, shift, and wear on the crank.
2. Catalytic converter: Apparently the mechanic wired-out the emission sensors about 6000 miles ago, and maybe it is coming back to haunt me with a backpressure problem, maybe due to chronic low O2 in the catalytic converter. (It got 30mpg much of the time.) Opinion: A fix is probably necessary anyway, but may not be possible to diagnose if there is a mechanical problem such as a valve or timing problem.
3. Timing belt: I think that I got it right, and both cam pulleys match, but I cannot pull the central cover off until I tear it down again. Same as above explanation on “valve medic” and octane. Same as above action on Woodruff key damage.
4. Unidentified Sensor failure: Throttle position sensor failure, resulting in bad fuel mix when throttle is opened? Pulling the plug did not seem to help. O2 sensor failure (is it even working if the OBD-II says “not ready”?) somehow causing too much back pressure in the exhaust system? EGR control (it sometimes opens at high rpms if the throttle is opened slowly and evenly, but usually it starts to move but then closes after a half second)? Action: Pull all sensors but crank, cam, and MAP and drive carefully, to see if the problem goes away. If so, then plug sensors back in one at a time. (Problem: many of the emissions sensors are in “not ready” mode and may already not be working.) Opinion: sounds simple enough, and it may reduce the number of variables in the system.
5. Valves: Maybe there is a sticking valve, which gets worse when the engine is hot, and screws up the emissions, and maybe “valve medic” loosens it. (Note, the 1996 EJ22 is reputedly a noninterference engine, so a timing problem will not directly result in a bent valve, and the compression check was good.) Action: If a bad valve can be demonstrated, then swap in a cheap junk-yard engine, and keep the spare parts. Opinion: I am not really set up to pull an engine, although I hear that it is far easier with a light high-mounted Subaru boxster than with deep, heavy Detroit V-8s.
Is pulling the spark plug while the engine is running and acting up a good way to identify a valve problem when the compression is okay? Will the spark plug packs tolerate a pulled wire?
Any suggestions as to where to start???
Thanks in advance!!!