cracked block-rebuild or replace and where?

I am the proud owner of a 1989 Wellcraft that was running just great until I heard a loud pop or cracking sound, and the engine died. Pulled the dipstick to find a sandy colored/feeling sludge. Water obviously in the engine. Never overheated or showed low oil pressure on the guage. It is a Chevy engine, 4 cyl, 3.0 litre engine with a Mercruiser outdrive. The outdrive is ok. I dont know whether to try to have it rebuilt or attempt to find a used motor for boat. Getting quote for used (unable to tell me hours on replacement) for 1,400 plus 300 to install with a 90 day warranty. This does not seem like a great deal and kind of "iffy". I am divorced mom who enjoys taking my son fishing. Please help with some advice. Have heard it all....A compression test was done, but that could still be a blown head gasket, though not very likely. Need to fix cheap and quick. Thanks for any help you can give.

Re: cracked block-rebuild or replace and where?

Usually a cracked block is a resuly of freezing. If this just occurred then it is either the head gasket or a previos crack that has re-opened.<br /><br />Sadly the only way is to pull the head to determine if it is the gasket. A compression test will not always detect a leak in the head gasket by the water jacket.<br /><br />If you had the time I would suggest a rebuild. Worst case is that the block is cracked. At least with a rebuild you will know everything that is new in your motor. Buying 2d hand is very "iffy".<br /><br />Bob

Re: cracked block-rebuild or replace and where?

Have the manafold and riser pressure checked first. This is the main cause of water in the oil on these puppys.

Re: cracked block-rebuild or replace and where?

To save money get the right diagnosis. Too many people change parts without it then wonder why it doesn't work!

Re: cracked block-rebuild or replace and where?

do as trent says. i got the same engine & had your problem last season. i replaced manifold & riser which solved it. post back, i'll let u know where u can get those parts at a very reasonable price if u need them. good luck.

Re: cracked block-rebuild or replace and where?

Does anyone know how to pressure test the manifold and riser to see if it is cracked or not?

Re: cracked block-rebuild or replace and where?

You dont have to pressure test it just pull the elbow fill the water jacket with water and see if it fills in the intake. then you have a bad manifold.This is probably a bad shutter(BACKWASH) or a blown head gasket. Get a compression test first and go from there.

Re: cracked block-rebuild or replace and where?

Sorry....But you must pressure check. Under some conditions the manafolds or risers will not show a leak until they get hot and expand..Pressure check. This IS a VERY common problem. Manafolds and risers normally last 4-6 years in saltwater and around 10 years or so in freshwater.<br /><br />Headgaskets can cause this problem but its normally the manafold or riser or both.

Re: cracked block-rebuild or replace and where?

Sorry, once a crack has expanded it wont contract and seal itself off.