cracked manifolds

[gators06]

I have an 1988 Mercruiser 4.3 alpha I stern drive which overheated and spilt water into the boat because both manifolds are cracked. I've been shopping parts online and see both intake and exhaust manifolds, are these the same thing? If not, which ones would I need to replace? How much should I be looking at for repair costs? Also heard engine block should be checked...

Thanks for any response>

[Valv]

You will have to look for exhaust manifolds. Are you sure they cracked due to overheating ? They usually crack due to non winterizing properly and freezing during winter months.

Your block should be checked too, if overheated.

I would take whole rig to dealer and have it gone through.

Unfortunately this means "bye, bye" boat for this year.

[BIG DS]

If you have water running into your boat while the engine is running, I would suggest taking it to a marine shop to have it serviced. If the manifolds are cracked it would more than likely be the exhaust manifolds and you can look at spending around $250 each or more. There is also a good chance that there is a frostplug popped out. Where was the boat stored this last winter and was it winterized? If not, was the water at least drained from the engine? If not, there is a good chance that the block is also cracked.

[gators06]

Most likely were cracked before it hit the water this year. Didn't winterize last year, garage stored and only took it out a few times - had people say it shouldn't need it. Learned the hard way that inboards don't self drain water like outboards do.

[Valv]

If I was you I would send the bill to the people that says inboard don't need it. They are actually the ones needing winterizing the most.

You are looking at a hefty bill here, don't be surprised.

[BIG DS]

IO's need to be drained!! There are several different petcocks on the engine so that you can drain everything. It would be no different than putting straight water in your cars cooling system and letting it sit in weather that gets to 20 below. The results will be the same. If your manifolds are actually cracked, there's a good chance the engine block and/or the heads are also. Your engine may possibly be junk.