Ran our recently purchased 1983 H34 for about 2 hours on Monday and to get the feel of the handling and to practice docking in good weather. Today when I went to work on another issue. I checked the engine (3GMF Yanmar) I noticed that there was oil leaking from the top of what I would call the rocker arm cover on a gas engine. There is a round raised spot near the last compression release lever and the oil seems to be leaking from that area. In prepping the boat the broker painted over the engine so can’t tell if it was a rust area or not. It was not leaking there before and we have run the engine a number of times. Today when I found it, it had been running for about 30 mins at the dock. Any ideas or suggestions, should I be worried? Is this part something I would be able to get replaced?
oil leak on H34
- Thread starter cjfj
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Are you sure it is oil? If it is diesel, that is right by the aft most injector and it could be you need new washers in the banjo fitting. Just went thru that myself. Look for bubbles around the top of the injector when the motor is running
Doesn't look like it's coming from the injectors, but I'll look again. It does seem to be oil, it is also right on top of the cover and spreading out from there.
If indeed it is oil coming from the engine, unless is has very recently been changed, it will be very black and it cannot be confused with diesel fuel. I had a problem a few years ago that makes me think you might have the same issue. I was finding that black oil near the same area that you describe, towards the back of the engine on top of the valve cover. Turned out to be a slightly cracked oil filler cap (the orange plastic cap with O-ring). I had probably overtightened it when doing an oil change and did not realize it. When running, oil would seep out and because of the engine being slanted towards the stern would flow towards the rear section of the valve cover. I got lucky one time as I happened to open the engine compartment immediately after shutting the engine and saw the stream going from the cap ! It was only being pushed out through the crack when engine oil was "pressurized" when running. Since the engine is slanted, the oil kept on going towards the back and nothing really showed near the cap after a few hours. Hope for you it's the same problem as it was a cheap solution. Good luck.
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thanks Clauade, I don't think this may be the same issue but it's something to look at again. I know that I had not tightened the oil cap down at one point and it was leaking around the cap, tightened and cleaned and no more oil around the cap. I did a search of the parts diagram and found that at the area it is leaking from there is a pin that goes through the top of the valve cover into the decompression lever arms or stand-offs. i've also noted that it is coming from all three pins. Different amounts at different times.
Someone on another foum said it might be caused by high pressure in the crank case due to clogged breather lines??? the broker I bought it from has a mechanic coming to look at it and a couple of other isses tommorow so I'll no one way or another real soon.
Someone on another foum said it might be caused by high pressure in the crank case due to clogged breather lines??? the broker I bought it from has a mechanic coming to look at it and a couple of other isses tommorow so I'll no one way or another real soon.
Just got the email from the mechanic, seems that the leak is coming from the pins on the decommpression levers. The good news is that it is just some epoxy that the factory covers them with that has dried out and is leaking, happens all the time he said. scrapped off the old added new and should not be leaking from that spot again. Now the rear seal on the other hand.......
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