replacing 2003 4.3 mpi freshwater cooled need recommedations

[trucknutz36582]

2003 Stingray MS 200
4.3 mpi with freshwater cooling for block, seawater pump rebuilt last year ... new sei outdrive upper and lower..

around 1300 hours my oil usage had gotten up to 1/2 quart per 30 minutes of run time.
oil leaking into the bilges... and I got Sea Tow'd back to the dock when pressure went to zero yesterday.
no amount of cranking would bring the pressure up beyond 5 psi...

pressure was 40PSI at 4,000 rpm before this event. it could it be a bad oil pressure sender, but considering the oil leakage and hours I think I want a new block..



Is the motor linked below a good starting point?
can I bolt all of my external accessories on this?


will be getting new exhaust manifolds.
I think I need a new Power steering pump too...
and maybe the oil cooler .... all these little things add up -

can anyone point me at a more complete motor that isn't 10 Grand? I think I am safe using the fwc parts - they are all in good shape.

thanks

PS. i have 3 weeks before vacation trip with family with boat ...

 

[alldodge]

I would suggest a long block like this a swap your stuff
http://www.michiganmotorz.com/vortec...ent-p-186.html

If you want a turn key drop in ready which include exhaust then for 8K
http://www.mercruiserparts.com/43-mp...l-engine-220hp

 

[alldodge]

You may or may not need a PS pump, most don't go bad, they only start leaking. So unless it ran dry then maybe its fixable.

If you see any metal in the PS pump, the might need to get another cooler. Not sure your motor has an oil cooler (need serial number) but if it does the same applies to that cooler

 

[Scott Danforth]

Your motor may just have the dreaded 4.3 leaking timing chain cover. Common on the 4.3's

 

[trucknutz36582]

Motor: M380325

Drive: M469721

Gimble: M557115

My serial numbers are listed above... I forgot to mention I checked the oil level while waiting for seatow and it was still at the top mark, so at that point
I was sure it was more serious than just low oil.

it's leaking oil on both ends.. so probably rear main seal as well.

I just found out that I can get the 4.5 MPI for only 500 more than the 4.3 mpi....

1.how can I find out if it is compatible with my jackshaft installation
2. Where / how do I find a factory trained mechanic in my area? It wouldn't hurt to get a quote from a pro, if they know what they are talking about..
and I am wondering if they get deep enough of a discount on parts that the cost of paying someone else to bust their knuckles wouldn't be too excessive?

past experience has shown me that I can do just about anything mechanically, but it often takes me 4 times as long than a pro would.

 

[alldodge]

Should be direct swap so long as it is a complete turn key motor. That said call Mercruiser customer service and ask them for dealers in your area 1 (920) 929-5040

Don't see anything about where your at

 

[HT32BSX115]

around 1300 hours my oil usage had gotten up to 1/2 quart per 30 minutes of run time. oil leaking into the bilges...

Howdy,

You're not "using oil" you're leaking it.

After a [satisfactory] cylinder leak-down test, and replacing the oil pressure sender and/or gage, I think I would just fix the oil leak above.
Pull the engine, replace the seals and check/reseal the front cover, valve covers etc.

1300 hours is not all that much time on any engine if it can produce adequate oil pressure and has satisfactory compression.

 

[trucknutz36582]

update - I did the following:
replaced the tall sierra oil filter with the Quicksilver filter
removed the low oil pressure switch,
installed a Bosch mechanical oil pressure gauge,
bypassed the low oil pressure sending unit with a paperclip

hooked up the hose ' n ' muffs in the driveway and turned on the water hose

it started up, but only after cranking for a while. I have the remote oil filter, so it probably took a while to fill that up, right? or should I have seen pressure right away?

it was very slow to build up oil pressure in the old gauge and the new bosch gauge, but eventually got to 20 psi on both gauges and running ok a little roughly.

idled around 800 rpm sounded normal ...
then when I tried revving it up after it got to about 1500 rpm and showed 42 psi on the mechanical gauge and 38 on the electronic gauge on the dash.

put it back into idle and let it run for a few minutes to get to 160 degrees.

it never got there - suddenly oil pressure seemed to drop and it stopped running.

checked oil level and found it was overfilled

pumped out about a quart of oil and returned it to full level

tried again - but the same result...


So now I am stumped - why would it run ok when cold and cr@p out just as it hits operating temperature?

the exhaust manifolds were barely warm - able to easily leave hands on them...

any suggestions for next steps would be appreciated,
as well as an idea what a reasonable price to pay for a merc mechanic to put it on an ecm reader, if that is indeed the next step

Thanks for all your good advice so far!

 

[alldodge]

Without the fuel filter being prefilled it would take some cranking.

Oil pressure taking a while to build up is not good, and dropping to zero even worst. Oil leaks can be fixed with seals and gaskets, but low pressure takes more doing. When the engine is cold the ECM gives the motor more fuel.

 

[trucknutz36582]

I've got a 1500 lb capacity harbor freight "crane" at home, but it does not have the reach to snatch the motor out of the boat, so I am taking the day off tomorrow to pull the engine with some help from a mechanic down the road - just load it off the boat and onto a utility trailer - in order to get to the mounts I have to remove the exhaust, which will make it a tad lighter and narrower anyway.
anything special needed to block it up until I can get it on an engine stand?

 

[alldodge]

Some 6x6 and 4x4 blocks will fill the need to level it.If you can get the boat under a strong tree, use can use a come-a-long

 

[trucknutz36582]

THANKS AllDodge! do you recommend taking off the main mounting Nuts from the engine mounts, or pull the bolts from the block?

 

[alldodge]

I normally remove the nuts, but most remove the bolts that fasten the mount to the boat. I would not remove the bolts to the block

 

[trucknutz36582]

port side nuts are off, but the starboard side are waayyy rustier. . I think some of the oil leaking on the port side helped keep the rust down.:lol:

soaking them now. I had to quit anyway - not because of the rain, but because of the lightning:scared:

 

[trucknutz36582]

failed compression test - 25, 28, 25 and 30 psi in 1 - 4 so i did not bother with 5 and 6.

pfft... time to get a new motor. adding oil did not make one bit of difference:faint2:

 

[HT32BSX115]

failed compression test - 25, 28, 25 and 30 psi in 1 - 4 so i did not bother with 5 and 6.

pfft... time to get a new motor. adding oil did not make one bit of difference:faint2:

Yup. Time for another engine, rebuild this one or a wrecking yard longblock.