Mikesspeed Posted July 20, 2005 Share Posted July 20, 2005 Hi very first post on this website so hopefully some you suby savvy people can help me out. It came to us first with a bad engine noise wich sounded like a rod bearing. The owners explained that he was bombing down the highway with the peddle to the mat and all of a sudden started hearing a knocking noise. Low and behold, #2 & #3 rod bearings were badly scored as was the crank. Everything was spec'ed out; crank bearings were spec'ed and ground, new rod bearings from subaru aslo spec'ed before install, erverything was cleaned and double checked and new gaskets. I should also mention that he has cat-back exaust, performance chip, iridium plugs/wires. About two weeks later 1500 kms, he comes back with again bad engine noise wich of course sounds like a rod bearing and again #2 & #3 crank bearing are done. Now before he recieved his car, oil pressure was checked a found to be ok. There are no signs of detonation on the pistons, no heat discoloration on the crank journals or rods. What gives!!! Ive been reading alot lately and have seen this issue resolved with a short block, but to go and buy a short block without knowing for sure the reason for this mess is kinda stupid. Any help is apreciated. Quote Link to comment Share on other sites More sharing options...
NorthWet Posted July 20, 2005 Share Posted July 20, 2005 Insufficient oil flow to the rod journal... (Duh!) I do not have a lubrication diagram for the EJs but the 2 likely causes are a plugged oil passage in either the oil feed to the crank (typically through a main bearing) or the crank itself, or oil flow being unable to reach the rod journal due to centrifugal force effects and/or excessive clearance on another rod/main journal fed off of the same oil source but closer to the feed passage. Where was the oil pressure checked? I do not know if the EJ25 has an oil gallery port/plug somewheres away form the oil pump. But pressure at the pump is just that: The oil gallery could be completely plugged just after the pump's discharge port and you could see good pressure at the pump. Quote Link to comment Share on other sites More sharing options...
Setright Posted July 20, 2005 Share Posted July 20, 2005 Above cylinder 3 there is plug for inserting an oil pressure sending unit. Tapping into this should give a good indication of running pressure. There is a belief that "dry cranking" these engines is essential after an oil change. Disconnect crank sensor to stop ignition, and crank until the oil light goes out. I don't do this, but I always brim the oil filter prior to screwing it on. I have heard and read people who insist that failure to dry crank leads to failed rod bearings. Sounds a little bit extreme to me. Northwet is certainly on to something, a narrowed/blocked passage would lead to starvation and premature failure. If the engine is still in pieces, make sure all the galleries are free from debris or sealant/gasket. Liquid gasket on the water or oil pump can leak into the oil galleries and cause problems. What above oil level? A rebuilt engine could consume a large amount of oil during running-in, failure to top off would also cause starvation. Overfilling could cause foaming, but the EJ engine series isn't particularly susceptible to this due to the plates and baffles in the sump and below the crankshaft. www.surrealmirage.com should be able to supply the original EJ technical papers, including oil flow diagrams. Quote Link to comment Share on other sites More sharing options...
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