Oil leak, front crank seal
#1
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Hey guys, I'm looking for some advice and info. Let me first say that I am new to power boating. I recently bought an 01 29 fever with the 500hp efi. The motor had been rebuilt recently, with all new gaskets, pistons and such, with about 40 hours of use on the new motor. This spring, I put about 3-5 hours of use on the boat, then changed the oil, filter, and fuel filter. Let me add that the previous owner was using straight 40 weight valvolene oil, and when I did the oil change, I switched to 25-50 mobile1. After the oil change, I put another 3-5 flawless hours on the boat. This past weekend, I put another 3 hours on the motor, with maybe 3 or 4 short wot bursts, but no more than a mile or 2 at one time. Then on Sunday, I checked the oil of course before I was going to use the boat. When I opened the engine hatch, I could immediatley see oil in the bilge. I checked the dip stick, and I was around a quart low. I filled the oil to full, and put the boat in the water so I could try and trouble shoot the leak. The oil looks to be coming out of the crank shaft, accumulating on the water hoses and then running down to the cooler that is below the crank shaft. While troubleshooting, I only ran the boat at cruise speeds, and checked the leak very often. It only seems to be leaking while the engine is running, and the oil up to an operating temperature of 200. And even then it's just a drip from the hoses. Nothing appears to be spraying. So at this point, I would have to say the crank shaft seal is bad? But this concerns me with this motor only having around 50 hours of use on it. Could there possibly be a big problem causing this, or just a coincidence a seal has gone bad, and just have it changed? Also, how intensive is this job, I'm sure the gaskets are peanuts, just curious on time and what exactly needs to be done. Thanks for the advise guys.
#2
Beak botr
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Similar Issue, I built an engine in 2006 and used synthetic oil on assembly. No issues for 3 years (changing oil once per season with synthetic), then when I did oil change the store was out of enough of the correct grade to do the oil change so I switched to a 20W-50 normal oil (was using 15-50 syn). After about 3 weeks, every time I would plane off, I would loose about 1/2 quart into the bilge coming from the rear main seal....!!! Have since rebuilt that engine and will stay with dino oil since that is what was used in the assembly. I discussed this with numerous people that said that the seal materials 'should' be impervious to this kind of problem, but I guess I was unlucky and got an old one that wasn't. I will not risk swapping type now, if I can't find the correct type, then no boating until I do.
#3
Charter Member # 55
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If the oil is dripping from the front side of the pulley it is probably leaking past the keyway slot on the balancer. If the oil is dripping from the back side of the balancer, then its probably the front seal. It could also be leaking at the base of the timing cover seal.
#4
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ok guys, I'm elbows deep in trying to get the bolt for the pully off, but when i put a breaker bar on it, the engine turns over. I'v also tried to rattle it off with an air impact gun with no luck. I tried also putting the boat in gear but the motor still turns over. How did you guys keep your motor/ crank shaft from turn when trying to get tha bolt out??
#5
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put a big board down and set breaker bar up on pulley. unhook ignition. crank starter. spins right off. just make SURE that breaker bar isn't gonna hit hull. this is a standard rotation motor, correct? if reverse rot, it will break the bolt. i did that on a Honda Civic.
#6
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ok, at this point i've kind of given up for the night. I figure, If I can break it loose with a minute of heat time from a tourch and an air impact, then that can't be the culperate of the leaky oil. (correct me if I'm wrong). I would guess that the bolt is put in there with at least red lock tite. my guess now is the leak has to be coming from the harmonic balance seal and at this point I think i'm going to have to take it to a marine mechanic.