My mercrusier 5.7 was recently rebuilt ,and now leaking oil.

[tigerhack]

My 5.7 mercruiser was recently rebuilt , i only run it for a total of 30 minutes for a few days , i notice the oil pressure begin to start drop and oil begin to start leak oil heavily somewhere behind the oil pan and the fly wheel , cant see clearly , the mechanic had change all seals now i have to take the engine back out , but what could cause the oil leaking ?, i am now waiting on the my friend with a backhoe to come and take it out , this really sucks.... what should i do ?, i have bought a brand new oil pump and also buy the seals over just incase .

 

[mkast]

Re: My mercrusier 5.7 was recently rebuilt ,and now leaking oil.

Rear main seal, sometimes your lucky, it doesn't seal.

 

[Don S]

Re: My mercrusier 5.7 was recently rebuilt ,and now leaking oil.

Cam shaft core plug behind the flywheel may have come out, oil pan gasket out of place or damaged, defective crankshft oil seal or improperly installed, hole in the oil pan, cracked block, who knows.
Only way to find out is to pull it out and look.
Are you sure things like the oil senders and oil filters aren't leaking?

 

[stinger222]

Re: My mercrusier 5.7 was recently rebuilt ,and now leaking oil.

I always prime the oil pump with a drill prior to installation because I had a new motor that was leaking bad from one of the cam core plugs. Apparently the plug was warped/threads messed up...I feel your pain.

 

[Mkos1980]

Re: My mercrusier 5.7 was recently rebuilt ,and now leaking oil.

If your loosing pressure, it could be the plug behind intake manifold on the china wall (OP sender may be screwed into there. Like mentioned above 1 of the 3 screw in oil passage gallerys on the backside of the block. (Only the fronts are pressed in) Could be the screw in plug half covered by the head, two of the oil plugs above the oil filter. I have had rear mains leak before and other leaks but it doesnt effect pressure.

 

[tigerhack]

Re: My mercrusier 5.7 was recently rebuilt ,and now leaking oil.

My 5.7 mercruiser was recently rebuilt , i only run it for a total of 30 minutes for a few days , i notice the oil pressure begin to start drop and oil begin to start leak oil heavily somewhere behind the oil pan and the fly wheel , cant see clearly , the mechanic had change all seals now i have to take the engine back out , but what could cause the oil leaking ?, i am now waiting on the my friend with a backhoe to come and take it out , this really sucks.... what should i do ?, i have bought a brand new oil pump and also buy the seals over just incase .

Thanks all for your response, i happen to have the engine out now, i see the oil pan seal man it was dripping some serious oil....but the oil look silver, no cuttings though....this engine consist of new ,connecting rod ,new piston new rings , to cut it short only thing not new is the crank shaft and the oil pump as i say i have the oil pump although the new one look smaller ,to me it looks like the shaving come off the connecting rod where it meets on the crank shaft just some small amount to make clearance it seems,what should i concern of ? and i am planning to flush the engine out ,what should i use ,do you think i have bad bearing again ?(OH MY Lord) thanks in advance.

 

[whywhyzed]

Re: My mercrusier 5.7 was recently rebuilt ,and now leaking oil.

and i am planning to flush the engine out

Silver oil and cuttings?

You can't flush out the problem, it's an engine not a toilet.

Take an oil sample, properly, and send it in for analysis for your future legal footing.

Get a proper filter cutter and disassemble the filter and put a magnet in the pleats and find out if it's aluminum or steel for starters.

Then rebuild or replace the engine.

 

[tigerhack]

Re: My mercrusier 5.7 was recently rebuilt ,and now leaking oil.

Silver oil and cuttings?

You can't flush out the problem, it's an engine not a toilet.

Take an oil sample, properly, and send it in for analysis for your future legal footing.

Get a proper filter cutter and disassemble the filter and put a magnet in the pleats and find out if it's aluminum or steel for starters.

Then rebuild or replace the engine.[/QUOTE


Engine Just Got Rebuilt now after i pull the engine crank case get to understand every Bearing is damage..

 

[mkast]

Re: My mercrusier 5.7 was recently rebuilt ,and now leaking oil.

The engine is already out.
Disassemble the engine for a detailed inspection.
Why?
How long did you want this engine too last?

 

[tigerhack]

Re: My mercrusier 5.7 was recently rebuilt ,and now leaking oil.

The engine is already out.
Disassemble the engine for a detailed inspection.
Why?
How long did you want this engine too last?

The engine was rebuilt and put in , now after running it a while it damage all the bearings, a mechanic say the crank shaft is bad.

 

[Bondo]

Re: My mercrusier 5.7 was recently rebuilt ,and now leaking oil.

The engine was rebuilt and put in

Ayuh,........

I'd find a Different Engine Rebuilder for the next attempt..........

 

[whywhyzed]

Re: My mercrusier 5.7 was recently rebuilt ,and now leaking oil.

Another option is to buy a GM 5.7 Crate long block for a truck, swap the core plugs to brass and go.
That way you can keep the other engine in pieces for the future legal procedings.
If you start working on the engine, you'll have no evidence.
What'd the rebuild cost?
Might be worth getting an independent failure analysis. Or, take it back and maybe the guy will fix his mistake and make it right.

GM 5.7 motors new are like $1900 or something rediculously low depending on what vintage yours is....

 

[tigerhack]

Re: My mercrusier 5.7 was recently rebuilt ,and now leaking oil.

Another option is to buy a GM 5.7 Crate long block for a truck, swap the core plugs to brass and go.
That way you can keep the other engine in pieces for the future legal procedings.
If you start working on the engine, you'll have no evidence.
What'd the rebuild cost?
Might be worth getting an independent failure analysis. Or, take it back and maybe the guy will fix his mistake and make it right.

GM 5.7 motors new are like $1900 or something rediculously low depending on what vintage yours is....

I had Just get a Chevy 350 engine one of my buddy , but it is seized up, i manage to have it turn 3/4 way ,should i just pull it down and rebuilt it , i will just change the rings i wont change the the bearings , i dont thrust the parts they sell here. and rather more i just dont want to mess with that , i plann to do this my self ,what amount of torgue should i put on the heads ? and what more should i take precaution of , i know i can do it better than that now hiding mechanic.

 

[Don S]

Re: My mercrusier 5.7 was recently rebuilt ,and now leaking oil.

If an engine won't turn over, it's probably going to need bearing to. but it will probably also need bored out, and new pistons.
Rusty cylinders is what locks them up (USUALLY) and the rust leaves deep pits in the cylinder walls that has to be smoothed up.
You better do it right this time, or you will be doing it again.

i dont thrust the parts they sell here.

Where is 'Here"?

 

[Mkos1980]

Re: My mercrusier 5.7 was recently rebuilt ,and now leaking oil.

Depends on the heads used. I go anywhere between 65-75 depending on bolt brand and whether or not I use straight 30w as a lube or some arp moly based lube.

 

[Mkos1980]

Re: My mercrusier 5.7 was recently rebuilt ,and now leaking oil.

Also be careful with the lifters. Dont over tightem them as most new people do. Esp with a flat cam. Too tight and hello new cam. Roller lifters are a little more forgiving. Since you have to pull the rods out to do the rings, you might as well mic the rods to see what specs they are at and put some new bearings in. Same for the crank.