lmdew Posted January 11, 2014 Share Posted January 11, 2014 154K on the motor. Previous owner had bent all 8 intake valves so I replace the valves and head gaskets. Runs great but using oil like mad. No external leaks, no smoke to speak of. Ran it 300 miles yesterday at 75 or so, down almost 3 quarts. PVC is valve is good Ran Seafoam in the oil for about 30 miles and then changed the oil before my 300 mile trip. Quote Link to comment Share on other sites More sharing options...
Fairtax4me Posted January 11, 2014 Share Posted January 11, 2014 Replace the PCV if its old, even if it rattles the valve mechanism can still be bad. If the oil changes were neglected at some point in the past the oil control rings may be seized, and could take some time to free up. Might try running some MMO in it and drive it easy for an hour or so, then change the oil again. Quote Link to comment Share on other sites More sharing options...
lmdew Posted January 12, 2014 Author Share Posted January 12, 2014 Backed it into the garage today and got on the throttle pretty good. Yes it smokes. Replaced the PVC valve and I'm running some MMO with the oil to see if it frees up the rings. Might be a rebuild. Hard to believe it runs so well. It's like I'm driving the old Caravan with the 3.0 smoker in it again. Thanks Larry Quote Link to comment Share on other sites More sharing options...
Fairtax4me Posted January 12, 2014 Share Posted January 12, 2014 Someone here had rings seized so bad they completely lost compression on one cylinder. MMO cleared it up and brought back compression. Worth a shot for the $8 for a bottle. Use a half quart now and the other half in the next change. Quote Link to comment Share on other sites More sharing options...
lmdew Posted January 12, 2014 Author Share Posted January 12, 2014 Thanks, have some MMO in it now and more visible smoke so it's doing something. Fingers crossed! Quote Link to comment Share on other sites More sharing options...
lmdew Posted March 1, 2014 Author Share Posted March 1, 2014 Back to this project: New Subaru PCV installed. It decreased consumption some but not much. Still using over a qt for every tank 300 miles. Ran MM Oil in the engine trying to free up any possible stuck rings Plugs very black and oily, Cylinder Compression Leakdown 1 135 100/96 = 4% 2 140 100/97 = 3% 3 140 100/97 = 3% 4 135 100/96 = 4% The leakage was heard in the oil fill, so it's going past the rings but I don't think it's excessive. For the Compression reading, remember I'm at 6300 ft here in Colorado so the numbers are lower than what you'd see at sea level. Once my Oil Pan Oring seal gets here I'm going to drop the pan and inspect that seal. If it's not that seal, what else could it be? The engine runs great, Head Gaskets just completed. No external leaks. New Subaru PCV. Quote Link to comment Share on other sites More sharing options...
1 Lucky Texan Posted March 1, 2014 Share Posted March 1, 2014 have you checked the oil pressure? just wondering if a stuck relief valve could cause high usage? I once read of someone that had the PCV and breather hoses all cross-connected and they had weird issues with oil. just wild guesses since you seemed open to them! Quote Link to comment Share on other sites More sharing options...
Fairtax4me Posted March 1, 2014 Share Posted March 1, 2014 Only other thing I can think of is maybe the PCV hoses are all clogged up with crud. You didn't ever say what engine this is. Quote Link to comment Share on other sites More sharing options...
luko Posted March 1, 2014 Share Posted March 1, 2014 If the PCV hoses were plugged wouldn't there be a vacuum in the crankcase...so you could put a vacuum gauge on the dipstick tube or the oil filler tube and see a vacuum on the gauge? Quote Link to comment Share on other sites More sharing options...
lmdew Posted March 2, 2014 Author Share Posted March 2, 2014 2001 2.5 SOHC. I will double check the lines, but I believe they are all correct and clean. Thanks, Larry Quote Link to comment Share on other sites More sharing options...
lmdew Posted April 1, 2014 Author Share Posted April 1, 2014 Gunk Engine Cleaner helped, as I ran the engine with it in the oil I could hear the change. The oil consumption is down but still high, a quart of more every tank, 300 miles. I can get the engine to smoke out the tail pipe if I rev the engine numerous times quickly Idle to 4000 RPM and back. Steady RPM it's no smoke. Review of items done and the engine: 154K 2.5 SHOC 2000 - Had bent intake valve, so I surfaced the head, glass plate and replaced and lapped all the valves. Engine runs great. - New Subaru PCV - All hosed clean and connected properly - Seafoam in the gas and Oil - MMO in the oil - Leak down check, see numbers above - Gunk Engine cleaner, seemed to help but did no solve the problem - No external leaks - Runs Great Pretty much down to stuck Oil control rings, engine pull. Thoughts? Quote Link to comment Share on other sites More sharing options...
Fairtax4me Posted April 1, 2014 Share Posted April 1, 2014 Did you ever remove the oil pan? There is a ring seal on the pan for a tube that connects to the bottom of the separator chamber. If the seal is broken or gone it apparently causes high oil consumption. High vacuum in the intake can pull oil past worn intake valve stem seals. Usually this is noticeable if you coast down a long hill in low gear that keeps the engine speed up and intake vacuum high for a prolonged period. Did you replace the stem seals when you did the valves? Quote Link to comment Share on other sites More sharing options...
lmdew Posted April 1, 2014 Author Share Posted April 1, 2014 Sad to say, I have not gotten to the Pan, nor did I replace the valve stem seals. I know I could do both with the engine in the car but might just be easier to pull it. It will go to the sideline for a month or so, got 6 other ones that I'm working on and lots of travel for work. Thanks for the feedback! Larry Quote Link to comment Share on other sites More sharing options...
Fairtax4me Posted April 1, 2014 Share Posted April 1, 2014 I'd have to call it stem seals. Keep 1/4 - 1/2 quart of MMO in it. The oil control rings lands in the pistons have drain holes that do have a tendency to plug up with infrequent oil changes, then the rings get stuck. MMO or a high mileage motor oil may clean them out. Neither one will hurt so its worth a shot. Quote Link to comment Share on other sites More sharing options...
lmdew Posted September 17, 2016 Author Share Posted September 17, 2016 Changed the Oil Pan return tube o-ring seal and the Valve Guide Seals. Some said it could not be done and I would not opt to do it again, but I was able to change the valve guide seals without pulling the heads. Installed the Timing belt so I could rotate the cams until there was no tension on the valves. Removed both sets of Rocker Arms Removed the Plugs Put the piston at BDC and put rope down the plug hole to fill they cylinder Rotated the crank to bring the piston up to compress the rope and hold the valve up Used a valve spring removal tool, the one that catches the keepers to remove the valve springs Used a Plug Wire Pliers to remove the old valve guide seals Installed and seated new valve guide seals Now the hard part, compressing the springs and getting the keepers in: I used a tool sold for this purpose, but it was too large for the Subaru Valves. I turned down the pin on the lathe. It worked about 50% of the time. When it didn't work, one Keeper was in the other was out. The last time I did valve with the heads off, I had made a valve spring compressor out of PVC Pipe. A 1 1/2 Tee with a 3/4" piece of PVC about 8" long works well. You can cut a 1/2" notch out of the end that will allow you to insert the keeper while you compress the spring. Motor in on my next free day, I hope this has solved the oil consumption issue. Larry Quote Link to comment Share on other sites More sharing options...
lmdew Posted September 20, 2016 Author Share Posted September 20, 2016 Sunday, I installed the motor. It started and ran great for about 20 minutes, and then started knocking, sounded like a rod knock. Shut it off, it was the end of the day. Strange it ran just like a Subaru should for 20 min. I had pulled the coil plug and cranked it to get oil through the engine before starting it and then when I did hook the coil up it started and ran great. Monday - Thinking one of the valve keepers may have come off, I pulled the fans, accessory belts and valve covers so I could check the valve keepers and crank it over by hand. - all valve keepers and valve train looked good - I pulled the plugs and turned it over by hand. About every 2 or 3 turn as #1 came up on compression the crank would lock up. I did not force it but it would not turn in the normal rotation with light pressure on my 1/2" ratchet. I'd back up the crank a 1/4 turn and then it would crank right through a couple more rotations of the crank. - Just putting my thumb in the plug tube, all cylinder have compression. When I put the plugs back in, one at a time compression felt good as I turned the engine over. - Everything back together and it's turning over fine, not locking up - I get it pointed out the back of work to drive it to the parking lot. - I start it, it's knocking - A minute or so later, the knock turns into what sounds like valve tick - Another couple of minutes and the tick is gone, it's running fine. - Park it for the night Any ideas what could have caused the Knock, locked up crank when turned by hand and then it goes away? Very strange. Thanks, Larry Quote Link to comment Share on other sites More sharing options...
Fairtax4me Posted September 20, 2016 Share Posted September 20, 2016 Lifters get air in them and collapse and they'll knock louder than a sonuvawitch for a little while then clear up as the air pumps out and they fill back up. Not sure why the crank would be locking up unless maybe there was a chunk of carbon or something in one of the cylinders. 1 Quote Link to comment Share on other sites More sharing options...
ccrinc Posted September 20, 2016 Share Posted September 20, 2016 Sad to say, I have not gotten to the Pan, nor did I replace the valve stem seals. I know I could do both with the engine in the car but might just be easier to pull it. It will go to the sideline for a month or so, got 6 other ones that I'm working on and lots of travel for work. Thanks for the feedback! Larry Ah, valve stem seals was what first came to mind. I'd bet they're hard and worn out and possibly now crooked because you had to replace valves. Emily Quote Link to comment Share on other sites More sharing options...
lmdew Posted September 21, 2016 Author Share Posted September 21, 2016 Installed new felpro valve guide seals. Maybe one of them was hanging up a valve slightly. It ran great to day. I ran it down the road for a mile or so. Hope the Subaru god is with me. Larry Quote Link to comment Share on other sites More sharing options...
lmdew Posted September 25, 2016 Author Share Posted September 25, 2016 Runs great, no knocks or valve noise. Down side, it's still using oil. It must be the rings. Looks like a core engine or will be soon. Thanks, Larry Quote Link to comment Share on other sites More sharing options...
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