1987 3.0L mercruiser mixing oil with water

[lancaster0321]

I recently bought a 87 stingray super sport with a 3.0 mercruiser was told it needed a head gasket, But I'm wondering if there's away to test it to find out if thats what it needs or could it be a cracked head, I've heard that you can do a compression test but I'm not sure what the compression range is. Is there any other way to find out what it could be?

 

[chiefalen]

Re: 87 3.0 mercruiser mixing oil with water

pressure test the water jacket, you will hear the leak. Could be the head, could be the head gasket, could be the mani, could be the riser letting water into the oil.

What do i think it is, cracked block, or head, i had the water jacket behind the neck of the t-stat develop a hole into the pushrod hole in the head.

First look at the block under the mani, look close at the casting plugs, you may see the crack ?

Pull the pushrod cover look at the block closely, see a crack there ?

Yes do a compression test all plugs out throttle fully down.