Still Water in Oil

[dsarazen]

I've got a 454, raw water cooled engine. Water showed up in the oil, so we first looked at the intake manifold. It appeared that the gasket was breached in a few places so we cleaned out the engine replace the gasket, oil filter, etc. and started it up. IMMEDIATELY, water in the crankcase. So...now we're looking to tear down the heads. My question, is that is it likely that the heads or head gaskets are the source of the leak, since the water entered the engine right away? I'm thinking that a cracked in block would allow water in, but more slowly. Here, as soon as be started it up, foam appeared. Also, compression is 175 on all 8 cylinders. Any help or thoughts is appreciated.

 

[bigbrownbuku]

Re: Still Water in Oil

are you seeing rust on any plugs? plugs will narrow down the location of the entry. is there an oil cooler installed?

 

[Don S]

Re: Still Water in Oil

Time to plug the water hoses to the exhaust manifolds, drain all the water, and pressure check the cooling system. Hopefully you will be able to hear the air escaping where the leak is.

 

[Haut Medoc]

Re: Still Water in Oil

I would suspect a bad exaust manifold. It's very common.Remove your plugs and crank the engine, if you've got water in your cylinders, that's probably it. J

 

[Don S]

Re: Still Water in Oil

With a bad manifold, it would take a while for the water to get into the oil, plus it wouldn't happen while the engine was running, only when it was off. Then it would have to fill the cylinders and leak past the rings. The amount of water, and it happening when running eliminates the manifolds.

 

[trog100]

Re: Still Water in Oil

yes its not entering the sump via the cylinders.. so it isnt the manifolds..<br /><br />trog100

 

[waterone1@aol.com]

Re: Still Water in Oil

First question, are you using marine intake gaskets ? I think there are some water ports that are blocked off on marine engines that are not blocked off in auto engines. Are you sure the intake doesn't have a crack or distorted mating surfaces ? When you re-installed the intake did you follow the torque sequence and values ? If it isn't related to the intake, I would suspect a cracked head and to a lesser degree head gasket. Don's suggestion to pressure check the cooling system would hopefully point you in the right direction.

 

[dsarazen]

Re: Still Water in Oil

Since it's raw water cooled, how can I block off the cooling system to pressure check it?

 

[vipzach]

Re: Still Water in Oil

I had problem with my intake/exhaust manifold, water leaking into the motor because of a crack in the manifold. It took several oil/filter changes to get all the water out of the motor.

 

[Don S]

Re: Still Water in Oil

Since it's raw water cooled, how can I block off the cooling system to pressure check it?

Depends on what year, make and model 454 you have.

 

[dsarazen]

Re: Still Water in Oil

it's a 80's remanufactured marine 454. the reman has less than 70 hours on it....got it from a seemingly reputable company...Orange Engine, in Orange County California. I has great compression still. How could a head or head gasket go? It's raw water cooled so it's never overheated.

 

[Don S]

Re: Still Water in Oil

Since you want to know how to go about pressure checking it, it would help to know how it's plumbed. Merc, OMC, Volvo, all do it just a little bit different, plus things changed year by year, so what we need to know is what it was to begin with. If it's a 1980 Mercruiser, it would be easy to look at the manual and tell you what to plug where to test it. But being a 80's reman means absolutly nothing.

 

[waterone1@aol.com]

Re: Still Water in Oil

You did not mention whether this was an inboard or I/O . In either case, find the water inlet hose going to the engine (after any sea water pumps, if equipped...do not confuse seawater pump with the circulating pump) go to the hardware store and buy some fittings and adapters to get that hose "down to" an air compressor fitting. This will be the point that you will connect to your air source. Now look at your exhaust manifolds and elbows, any rubber hose that goes to the manifolds and elbows must be removed from them and the hose ends securely plugged. Now you are ready to connect to an air source of about 15 lbs....do not go over 20 lbs ! You will need quiet so you can listen for where the air is escaping. Having a 2 or 3 foot piece of 1/2" or 3/4" inch hose that can be used as a stethescope can be a real help. By the way, don't worry about the thermostat not being open, it has been my experience that they don't seal 100% and will definetly let air pass.