New long block leaking oil

[garbageguy]

Recently got a 5.7 long block (info below), it ran great on the stand, and in the boat when installed - life was good. But no - getting (nice clean) oil leak into the bilge of 1998 Wellcraft 240 SE. Have been told it's leaking from the crankshaft seal, and could possibly repair this leak with the engine in the boat. Does that seem possible? Any other thoughts, ideas, encouragement, are welcome.

Mercruiser 5.7 260HP 1996-2001, w/oil pan & plastic timing cover,w/o crank
sensor EFI,
fuel pump does not mount on blk, Blk #880, Head #906, Refer #320001, Part
# 3200.2 3 months warranty on parts, $2150.00

 

[Bondo]

Have been told it's leaking from the crankshaft seal, and could possibly repair this leak with the engine in the boat.

Ayuh,.... The front seal, Possibly,.... The rear seal, No way,....

Probably easier to do either of 'em, by pullin' the motor though,....

 

[garbageguy]

Thanks for the reply Bondo, as I know my thoughts are not always the best on these things. I guess I'll hang on to "possible" at the moment.

 

[flipbro]

There was a post on here recently were the plastic plug they used to plug the hole were the crank senser would have been came out. Sound like it was the same set up motor. Are you sure it's a main seal? The new one piece rear mains seldom leak unless there's a ton of hours witch isn't the case hear..

 

[Grub54891]

Lay some oil sobs under the motor and run it for a bit. The oil will drip on them, then look directly above where they get wet.

 

[garbageguy]

flip - fortunately, it doesn't seem to be the rear main seal. All holes are plugged.

Grub - good idea, we've verified its from the front of the engine

Update,
Tried a harmonic balancer repair sleeve. Good new is it could be done with engine in the boat. Bad new is, still leaking. So it's off to get a new timing chain cover...

 

[Volphin]

I've never been a fan of the new plastic timing chain covers. It seems like they are always a failure point.

 

[skippy2235]

Mine was a rusty oil pan that metal rusted away, took me 2 weeks to find, and put a screwdriver through the pan.

 

[Grub54891]

The timing cover has to be installed loosely, then the pully installed, then snug up the cover so it's all aligned. I think there is a special tool for that but I've never used one. And them plastic covers are a one time use item.

 

[garbageguy]

Got a new timing chain cover. Able to install the balancer sleeve with motor in the boat, fortunately the puller fit. Does the oil pan have to be dropped to get the timing chain cover replaced?

 

[Bondo]

Does the oil pan have to be dropped to get the timing chain cover replaced?

Ayuh,.... That's correct, the cover is under the pan,...

 

[garbageguy]

Thanks Bondo. Does the pan need to be completely removed, meaning the motor has to come back out, or is there any hope it could be dropped just a little while still in the boat?

By this time of year, if she comes out of the water to pull the engine, that probably spells a complete lost season. Just hopin' to get a few fall runs in before the water turns hard...

 

[biggjimm]

Should be able to just loosen the front couple bolts on the pan to get your new timing cover on. Install like grub said above or you'll probably be doing it again. Jim.

 

[garbageguy]

update: engine had to be pulled to get it sealed, but now we're back in business - thanks for everyone's input

 

[1979 Quartermasters]

I put two of those Dorman plastic covers on and could not stop the leak. Finally. I just glued a metal one on and no more leak. I hope yours holds. I found the round rubber gasket, molded into the cover didn't seal on the block. I had my motor out three times that summer. Got pretty good at pulling it and putting it back in.

Ken

 

[R055]

I put two of those Dorman plastic covers on and could not stop the leak. Finally. I just glued a metal one on and no more leak. I hope yours holds. I found the round rubber gasket, molded into the cover didn't seal on the block. I had my motor out three times that summer. Got pretty good at pulling it and putting it back in.

Ken

I went through 2 dorman covers too. The first one I did the shortcut way so I bought another dorman cover and dropped the oil pan in the boat and even replaced the oil pan gasket and did everything right and it still didn't seal. The season started and I didn't want to loose anymore time so I took off the harmonic balancer, cleaned all the oil off. Applied a layer of rtv sealer on the bottom half of the timing cover anywhere the timing cover meets the oil pan or block. Waited 24 hours and re applied the rtv sealer on top(I did this 4 times). Ive driven it 20 hours and no leak yet.

At 10 hours though the fake crankshaft sensor started leaking so I removed it applied rtv sealer on it and screwed it back in. And then rtv sealer on top of the screw just to be safe.

I will be taking the engine out in the fall to do the job correctly.

 

[garbageguy]

As I noted previously, after trying 2 of those (Dorman?) covers, engine pulled early this season, put on metal cover, engine back in, been boating since - phew!

Now, my question is on break-in, and first oil change. It was suggested at 25 hours. I've got 34 hours on 'er - do you think I'm OK to go another 5 or 10 hours til first oil change? Got a little weekend get-away planned with the Admiral, wondering if I need to cancel it til I can get to the oil change. The oil is full and clean on the dipstick. All input welcome. Thanks.

 

[R055]

As I noted previously, after trying 2 of those (Dorman?) covers, engine pulled early this season, put on metal cover, engine back in, been boating since - phew!

Now, my question is on break-in, and first oil change. It was suggested at 25 hours. I've got 34 hours on 'er - do you think I'm OK to go another 5 or 10 hours til first oil change? Got a little weekend get-away planned with the Admiral, wondering if I need to cancel it til I can get to the oil change. The oil is full and clean on the dipstick. All input welcome. Thanks.

For the metal cover you used are you talking about the metal pre vortec covers or the vortec aftermarket covers?

 

[garbageguy]

R0 - I will try to find out, but I'm not sure of the distinction you're asking about

 

[flipbro]

I would go enjoy your weekend. It wont hurt things to go a few more hours.