Found oil and water in my 1990 Mercruiser 5.7 Now what?! PICS INC

[carrera205]

So after a carb rebuild I get the motor fired back up and suddenly I notice "milkshake" dripping from the dipstick tube... awesome. So I drain the oil and sure enough i get the milkshake looking oil/water mix. No I'm trying to decide what next. The engnie is a 1990 5.7 Mercruiser S/N D383675. The engine has never been rebuilt so maybe it's time. Hoping it's not a cracked block. Anyone been here what did you do?

 

[Bondo]

So after a carb rebuild I get the motor fired back up and suddenly I notice "milkshake" dripping from the dipstick tube... awesome. So I drain the oil and sure enough i get the milkshake looking oil/water mix. No I'm trying to decide what next. The engnie is a 1990 5.7 Mercruiser S/N D383675. The engine has never been rebuilt so maybe it's time. Hoping it's not a cracked block. Anyone been here what did you do?

Ayuh,.... Welcome Aboard,..... Order a new rebuilt long block,.... That's the Most likely explanation,....

How 'bout a little back story on it,...
How long ya had the boat,..??
Who winterized it, 'n with what method,..??

 

[carrera205]

I've had the boat personally for about 4 years. Before that it was my dad's since about 1992 and I inherited it when he passed about 4 years ago. I generally winterize it by draining the block and fogging the motor with fogging spray. It's fresh water cooled. We had it out last summer no problems and after I got the carb back on after a carb rebuild i started it up and noticed milkshake dripping from the top of the dip stick tube. Hope this is the info you're looking for.

Brad

 

[alldodge]

It was a real cold last winter and my guess is there was some water left in the block and it cracked. We pull the drain plugs and if you don't stick a wire of small screw drive in the drain hole it may not drain completely. You could start with pulling the heads to see if that is where the crack is but maybe just pull it all out and decide if a long block is a better option

 

[Fastatv]

I've had the boat personally for about 4 years. Before that it was my dad's since about 1992 and I inherited it when he passed about 4 years ago. I generally winterize it by draining the block and fogging the motor with fogging spray. It's fresh water cooled. We had it out last summer no problems and after I got the carb back on after a carb rebuild i started it up and noticed milkshake dripping from the top of the dip stick tube. Hope this is the info you're looking for.

Brad

You have not had it out or ran it any this year until now? More than likely you have a cracked block..or something cracked. However, the carb has been off for rebuild....did you seal off the intake manifold...was the boat covered well...any chance the engine could have been rained in? This is a long shot but, you just changed the oil, right? Idle it on the muffs for a few minutes...slightly above normal idle to ensure you pull in enough water, warm it up...change the oil again and see what you have.

 

[carrera205]

So I store the boat in my shop so it's always out of the weather until summer comes around and even then the engine is covered. I changed the oil last summer and was going to warm it up drain it and change it. So what block is this? I'm looking around at bare blocks so when I pull it I can break it down use what I can and rebuilt a new one. I can't figure out if this is the normal short block or long block.

Brad

 

[Fastatv]

So I store the boat in my shop so it's always out of the weather until summer comes around and even then the engine is covered. I changed the oil last summer and was going to warm it up drain it and change it. So what block is this? I'm looking around at bare blocks so when I pull it I can break it down use what I can and rebuilt a new one. I can't figure out if this is the normal short block or long block.

Brad

To make it short in wording....a short block is the block only, complete less heads, intake, oil pan. A long block is the more complete of the two...its basically the short block with heads, ie, long block.

 

[HT32BSX115]

I generally winterize it by draining the block and fogging the motor with fogging spray. It's fresh water cooled.

Howdy,

Welcome aboard!


Can you reveal a little more info? For all the rest of the people reading this thread, What exactly do you mean by "fresh water cooled"?

Does the engine have a heat exchanger installed and did you have the correct "mix" of antifreeze in it? If it's REALLY "Fresh Water cooled" why were you draining the block?

I am guessing that by "fresh water" you mean that you OPERATE in "Fresh Water" and the engine is RAW WATER cooled.

If that's the case, If you don't find an obvious source of water intrusion, you might try pressure checking the block........... but, like everyone above, I suspect you might have NOT gotten all the water out of the block when you drained it.

If you decide to replace the engine, you can get a wrecking yard engine out of a similar year pickup truck and swap all the marine "stuff" over and it will usually work fine. Install a "marine" water pump and core-plugs (AKA soft/freeze plugs) with brass models.


Regards,


Rick