Oil leak 1999 225 optimax

[mudron08]

Serial number: 0G927739
So I have oil leaking and i am going to clean and degrease the engine this weekend when the weather warms up, but I have a suspicion that the oil is coming from a white plastic elbow on top of the intake manifold that has a hose running back to the compressor with a brass/bronze check valve looking part in the middle of the hose. It has the most concentration of oil around it and it is also the highest point in the engine with oil on it. I guess my question is, is this possible to be leaking oil while running or should I be looking elsewhere when I clean and check with powder? Thanks for the help.

[Bob G.]

If you are using Mercury DFI oil, use a UV light to make seeing the leak easier.

[mudron08]

Thanks for the idea, I have one and will try it out once I get it all cleaned up.

[EuropeanAM]

I'd be quite surprised if your primary leak is coming from there. Not impossible, though.

Better check the oil pump itself (and likely not the hose connections, the actual PUMP).

[mudron08]

Oil pump is dry, most of the oil is located on top of the intake manifold around and near that white elbow. Would this leak more at higher rpm?

I'd be quite surprised if your primary leak is coming from there. Not impossible, though.

Better check the oil pump itself (and likely not the hose connections, the actual PUMP).

[DewRonInc]

Might just need to re seal elbow, probably all it is

[EuropeanAM]

Possibly- especially if loose or in need of sealant. If you're going to have to fix a leak... this is about the easiest and least expensive of all.

[mudron08]

What would you recommend resealing with?

[DewRonInc]

I personally like a Teflon based sealant, arp has a outstanding product, but u will have to order.

[blacknitro]

That white plastic elbow developed a crack in a 1999 225 optimax I had. I removed it and found a 90 degree hose barb with female threads that matched the post that was inside that plastic elbow. Some Teflon tape and the 90 degree hose barb fixed it.

[mudron08]

I plan on removing that elbow this week once I finish another project on the boat. I tried finding a new one through Mercury but to no avail, I’ll probably end up doing the same as you if it’s cracked.

That white plastic elbow developed a crack in a 1999 225 optimax I had. I removed it and found a 90 degrees hose barb with female threads that matched the post that was inside that plastic elbow. Some Teflon tape and the 90 degree hose barb fixed it.

[EuropeanAM]

I seem to recall that I replaced one several years back and had to switch to a brass-elbow.

[blacknitro]

Don, I think you posted something a while ago that was real helpful. I recall something about removing the intake, drilling out where that elbow is and then tapping it for the brass elbow. I remember reading it and thinking that would be the best way to fix it.

[mudron08]

I found the crack in the elbow. It was open enough to fit my finger nail in it. Is the brass piece threaded in or press fitted? Also could anyone point me in the right direction for a service manual? Thank You.

[SilverFox579]

Also could anyone point me in the right direction for a service manual? Thank You.

If you want to order or price Mercury Engine Parts or Accessories

[JOE54]

brass fitting most likely threaded , 855348R02 should be manual for your engine / used for ser numbers 0g590000-0g960499

[mudron08]

Thank you, Joe. I will see what I can find.

[mudron08]

Would it be frowned upon to place a hose over the brass fitting that is in the manifold and connect it to a brass elbow that would replicate what was installed originally? If the brass elbow is sticking up 1/2" and the barbs on the elbow are 1/2" long then my thought was to cut a 1" long piece of tube and connect the two together. The only difference from original is that it will stick up a bit higher. I have already checked and there is enough clearance under the black plastic intake cover. I just want to do this to confirm that this was were the leak is before pulling the intake manifold to drill and tap for a pipe thread and installing an elbow. Thank You.

[JOE54]

should work fine