2014 Honda CRV, K24z6, 91k miles
Short Version: I believe I have oil leaking past the rings in one cylinder sufficient to cause an intermittent misfire on startup and am debating replacing rings vs replacing the engine.
Long Version: Recent used car purchase. Car will trigger a cylinder 3 misfire on cold start up roughly 10% of time. Scan tool shows no misfires after 45 seconds or so. 50/50 on if misfire will be severe enough to cause ECU to disable #3 fuel injector, but resetting code will cause vehicle to drive normally. Dealer replaced plugs and coil as courtesy despite sale being as-is. Swapped coils and fuel injectors and problem stays on cylinder 3. Borescoped engine and cylinder 3 appeared wet. Initially suspected head gasket/coolant leak, but head gasket leak test (where you pull air from the radiator though a fluid which will change color if exposed to exhaust gasses) was negative. Added UV dye to coolant, and piston top does not fluoresce. Long “q-tip” sample of piston top seems consistent with motor oil. Replaced valve stem seals with no improvement.
When I replaced the valve stem seals I leaned that someone of had removed the timing cover before and left out one bolt and left another only hand tight.
I am considering attempting to replace the pistons rings while leaving the engine inside the vehicle, essentially using the method outline in this TSB for an slightly earlier CRV (https://static.nhtsa.gov/odi/tsbs/2018/MC-10152429-0001.pdf).
A friend, who has rebuilt several Honda engines, advises me that engine has likely been overheated, and that Honda’s don’t do well when they’re overheated and I will likely need to send the block to a machine shop. I’m not sure I agree. The head gasket isn’t leaking currently, so I’m not convinced the block should be warped, and I’m not convinced there should be much wear on a 91k mile engine. This would be the most complex repair I’ll have attempted. If I pull the head the block is warped or there any other problems on the lower end, I’d give up and have the car towed to a shop for an engine replacement.
I’ve inquired with my mechanic about an engine replacement. Unfortunately, he can’t source a replacement engine from his normal suppliers. He’s willing to install an engine are a reasonable rate if I bought it, but I really don’t know where to look, and searches online seem to show that nearly all engine remanufacturing outfits get mixed reviews as best (although I’m sure there is some selection bias in that). I’m really not interested in gambling on junkyard engine.
I have several related questions:
Short Version: I believe I have oil leaking past the rings in one cylinder sufficient to cause an intermittent misfire on startup and am debating replacing rings vs replacing the engine.
Long Version: Recent used car purchase. Car will trigger a cylinder 3 misfire on cold start up roughly 10% of time. Scan tool shows no misfires after 45 seconds or so. 50/50 on if misfire will be severe enough to cause ECU to disable #3 fuel injector, but resetting code will cause vehicle to drive normally. Dealer replaced plugs and coil as courtesy despite sale being as-is. Swapped coils and fuel injectors and problem stays on cylinder 3. Borescoped engine and cylinder 3 appeared wet. Initially suspected head gasket/coolant leak, but head gasket leak test (where you pull air from the radiator though a fluid which will change color if exposed to exhaust gasses) was negative. Added UV dye to coolant, and piston top does not fluoresce. Long “q-tip” sample of piston top seems consistent with motor oil. Replaced valve stem seals with no improvement.
When I replaced the valve stem seals I leaned that someone of had removed the timing cover before and left out one bolt and left another only hand tight.
I am considering attempting to replace the pistons rings while leaving the engine inside the vehicle, essentially using the method outline in this TSB for an slightly earlier CRV (https://static.nhtsa.gov/odi/tsbs/2018/MC-10152429-0001.pdf).
A friend, who has rebuilt several Honda engines, advises me that engine has likely been overheated, and that Honda’s don’t do well when they’re overheated and I will likely need to send the block to a machine shop. I’m not sure I agree. The head gasket isn’t leaking currently, so I’m not convinced the block should be warped, and I’m not convinced there should be much wear on a 91k mile engine. This would be the most complex repair I’ll have attempted. If I pull the head the block is warped or there any other problems on the lower end, I’d give up and have the car towed to a shop for an engine replacement.
I’ve inquired with my mechanic about an engine replacement. Unfortunately, he can’t source a replacement engine from his normal suppliers. He’s willing to install an engine are a reasonable rate if I bought it, but I really don’t know where to look, and searches online seem to show that nearly all engine remanufacturing outfits get mixed reviews as best (although I’m sure there is some selection bias in that). I’m really not interested in gambling on junkyard engine.
I have several related questions:
- How normal is it see a problem present on only one cylinder? Should this cause me to worry that it something different from a normal stuck oil control ring issue?
- How likely is the lower end to need machine shop work?
