I know I'll probably get a bunch of wise a@# answers, but I need insight on this one. I have an oil leak somewhere around the starter motor on a Merc. 502. It appears to be a slight spray as opposed to dripping. I have looked all over with a flashlight and mirror to try and locate the source to no avail. It has to be very small because my oil level never appears to change, but it does leave quite a mess on that side of the bilge, and of course mixes with the water as I'm splashing around creating a mess!!!! I checked the dip stick and oil pan seals and they look fine. Anyone have any ideas??

Thanks in advance

man I hope it's not a rear main oil seal leaking there, most of the time they leak more to the back but will sling some oil when you run it. not much left in that area though, look up high and make sure the leak is not dripping down say from a valve cover gasket, or something like that, good luck

I was going to say the same thing as H2X....rear main seal could be going bad. The flywheel will sling it around some. Or there is always the simple valve cover leak (I've had this happen to me more than once). Also, the starter itself has grease in it.....could it be leaking and slinging when you engage the starter?? Not sure about this though.....never seen it before but it seems like it could happen.

The odds are it is the valve cover. I'd change the valve cover gasket and hope it goes away. How old is the engine? What year and how many hours?

The engine is suppose to have approximately 10 hours on it. It was built by Proroc in New Jersey. The oil is definately not from a valve cover gasket as it is not drops I see. I taped a white rag on the side where I thought the source was, nothing at idle, but after running open, there was a definite oil spot on the rag. It is right near the front of the starter area. Its so hidden, I've tried looking at it with a mirror/flashlight burnig myself on the exhaust etc...

If it were a main seal, why would it only be slinging it on the starboard side? Also, wouldn't my pressure be lowered on my gauge?

Thanks for your help so far, please don't give up!!!!

I had a rear main seal problem, and it turned out to be to much oil in the pan. The oil came out the main seal and into the bell housing where it filled in a little because of the dust plate on the inside of the bell housing. The bottom of the flywheel throus the oil to the port side and it did appear it was coming from the starter area. It ended up being my fault because somehow I was running 11.5 qts. in a Dooley 10 QT pan, (its really only a 8 - 9 qt pan, but advertised as 10) Anyway, if you are running an aftermarket pan and trying to run max capacity that could be it. Let us know what you find out.

The rear main seal can leak and you will show normal pressure on the guage. Can you go back to the builder? Will they stand behind their work? Your motor is to new for you to be burning up your hands and arms on. You may not know what the problem is until you pull your engine.

Some guys have talked about napa having a oil additive that makes the leaks easier to find. I think it works with a special light. It might be worth a try if the engine builder will not help.

Good Luck

Does the dipstick enter the oil pan in front of the starter like most 454's?\ . Could be forcing some oil out there This would problably not happen at an idle , yet would at higher speed

sounds like you need to crawl into your engins compartment and watch it with a flash light while someone puts it on plane,unless theres a prop shaft dyno in your area,to much oil could be a problem as the crank with start to sling the oil,pull the starter out and inspect behind it,that'll give you an answer on the rear main,the dipstick should have a small bead of silicone around it were it enters the block,if not it will seep.......also try putting a wrench on a few oil pan bolts in that area just to see if they might be one a little loose.....what year motor is it,might not have got a good seal at the corners of the pan if its a GEN 1V......good luck

I'm going to pull the starter and water lines today. Good thing I'm a small guy, I might just fit in the little space to work on this. I checked the dip stick tube...no leak. checked the oil pan...no leak. The block is a 1999.

The engine builder is Proroc in New Jersey. They haven't returned my calls. I was informed that they were a very reputable builder. I'm not going to bash them, might not be their fault. But I wish they would at least return a phone call and assist me on a 10 HR engine that they built.

I'm decent mechanic, but never worked on boats too much. Do I need to pull the drive to pull the engine if it gets that far? Again, any help is greatly appreciated.

Thank You