water in all 4 cylinders

[ScottinAZ]

Engine is a 1980 "ish" vintage Mercruiser 120 S/N 5612859. During testing for re-commissioning, I am running on hose water hooked direct to the inlet hose (no drive installed). Engine runs good, but am getting milkshake in the crankcase, and when I pulled the plugs this morning, and cranked it over, I got Old Faithful from all four bores. To my knowledge and understanding, that does NOT indicate a cracked head or cylinder, as that would only affect one cylinder. I am thinking the manifold may have packed in, but do not know the condition of the gasket going to the "riser/elbow/thingamagig" that connects to the manifold. No sense in "pressure testing" as it leaks on straight free flowing hose pressure. What would be the likely failure points for these symptoms. Right now I gotta go WD-40 the bores to keep them from rusting up......

I DO NOT KNOW the full prior history of the boat or motor. I bought it this summer as a project, and it has not been registered and on the water since 2014. This is Arizona, so we dont typically get hard freezes that would compromise the block (it can happen, but its rare). I bought the boat out of Tucson, so it gets hot, but not "cold".

 

[itsathepete]

Manifold gasket or head gasket. Compression test, if good, will rule out head gasket

 

[Scott Danforth]

You need to acetone test the manifold and elbow

Pressure test the engine water jacket (should hold 15 psi forever)

Do a compression test, and a leak down test

 

[ScottinAZ]

Manifold gasket or head gasket. Compression test, if good, will rule out head gasket

which manifold gasket, at the head, or the one going to the riser/elbow?

 

[ScottinAZ]

You need to acetone test the manifold and elbow

Pressure test the engine water jacket (should hold 15 psi forever)

Do a compression test, and a leak down test

Ill get the manifold pulled here today and start checking it.

What is a good way to seal the engine to test it. This is an open system, so there is no radiator cap to hook the tester to. My guess is to seal off the port going to the manifold, and hope for the best?

I got to find my compression tester. I dont have a leakdown rig (nor an air compressor to run it here at the house, so that will have to go on faith (or constructive teardown (headgaskets arent that expensive....)

 

[itsathepete]

Water in oil causing milkshake is more likely head gasket than manifold gasket but could be cracked block or head. Water in cylinders could be any gasket, head, manifold, or elbow

 

[Scott Danforth]

Ill get the manifold pulled here today and start checking it.

What is a good way to seal the engine to test it. This is an open system, so there is no radiator cap to hook the tester to. My guess is to seal off the port going to the manifold, and hope for the best?

I got to find my compression tester. I dont have a leakdown rig (nor an air compressor to run it here at the house, so that will have to go on faith (or constructive teardown (headgaskets arent that expensive....)

It's almost never the head gasket

To test the water jacket. Drain the block and head, take a hose that comes from the transom shield and the hose that feeds the manifold and tie them together. I use my mityvac pump

You can borrow a compression tester from your local FLAPS

 

[ScottinAZ]

well, we have a verdict.... its coming in through the exhaust..... pulled the upper intake, and there are signs of water in the past, but no standing water in the intake side of the house. Exhaust side is different.... pulled the elbow, and there was water up to the port level in the manifold. Still need to pull the manifold for acetone testing, but there was a good 1/4 pint in the exhaust tract. I still need to clean the gasket surface and ascertain its condition, but at the very least, it crapped the gasket. I sucked the water out of the exhaust tract, so now off to pull the manifold....

 

[ScottinAZ]

aaaaannnnnddddd we have a confirmed kill..... Exhaust elbow is dead. As fast as you can pour acetone into the water jacket, its pouring into the exhaust tract..... burned out at the top of the elbow.... well, there goes $180 bucks..... and my season....

 

[itsathepete]

aaaaannnnnddddd we have a confirmed kill..... Exhaust elbow is dead. As fast as you can pour acetone into the water jacket, its pouring into the exhaust tract..... burned out at the top of the elbow.... well, there goes $180 bucks..... and my season....

That stinks, but it's better than a cracked block or head. Or whole manifold

 

[ScottinAZ]

That stinks, but it's better than a cracked block or head. Or whole manifold

if one has to go, thats the best one.... still need to acetone test the manifold. One of the downsides to living in a "small" town, is that the stores open late on Sunday, and are closed on Holidays..... I need more acetone and a couple shorter bolts to hold one of the plates on the manifold..... Looks like Tuesday or Wednesday before I'll be able to get that tested....

 

[Scott06]

Would spray wd40 in cylinders and turn it over with out spark and get the milky oil out of the pan

When you get the manifold and riser back on get it running and change the oil multiple times until it runs clean. Change oil let it idle until hot change it again , can do that with only 3 qts in pan. Walmart super tech is the cheapest oil out there for something like this

 

[ScottinAZ]

Would spray wd40 in cylinders and turn it over with out spark and get the milky oil out of the pan

When you get the manifold and riser back on get it running and change the oil multiple times until it runs clean. Change oil let it idle until hot change it again , can do that with only 3 qts in pan. Walmart super tech is the cheapest oil out there for something like this

Already did this. Drained milkshake yesterday, and left the drain plug out overnight. After finding Old Faithful this morning out of the plug holes, I sprayed wd-40 into the cylinders and cranked it over, then repeated a couple more times for good measure. After finding the elbow shot and the exhaust full of water, I did it again after pulling the manifold off...... Engine has been refilled with oil (its my good oil, its what I had on hand.....) and filter changed. Cranked engine plugs out until got oil pressure to ensure I got it throughout the engine. Once I get the manifold back on, and the riser replaced, Ill change the oil a couple more times for good measure. The engine was running good before this, so I really didnt want to leave water where it would cause issues....

 

[Scott06]

Already did this. Drained milkshake yesterday, and left the drain plug out overnight. After finding Old Faithful this morning out of the plug holes, I sprayed wd-40 into the cylinders and cranked it over, then repeated a couple more times for good measure. After finding the elbow shot and the exhaust full of water, I did it again after pulling the manifold off...... Engine has been refilled with oil (its my good oil, its what I had on hand.....) and filter changed. Cranked engine plugs out until got oil pressure to ensure I got it throughout the engine. Once I get the manifold back on, and the riser replaced, Ill change the oil a couple more times for good measure. The engine was running good before this, so I really didnt want to leave water where it would cause issues....

Good deal

 

[Rick Stephens]

Pressure test the block regardless of the elbow.

 

[ScottinAZ]

Pressure test the block regardless of the elbow.

planned on it.

 

[ScottinAZ]

ok, in case anyone wants to see (kinda) what the inside of a burned out elbow looks like, here ya go. You can see it much clearer in person, but there is an obvious "step" where the inner wall between the water jacket and the exhaust tract as seen from the outlet nipple where it connects to the bellows going to the "Y" pipe (that only has one leg on my 4 banger). it also sounds like a baby rattle when you shake it, and this is only a small portion of the crusty crap that came out of the elbow. Larger chunks of rotten rustlike material. My bet is this is one of the reasons the boat was initially parked. this didnt happen just due to some water that was sitting in there during a storage period, as this is literally the highest part of the cooling system before you get to the exit.

on the plus side, the manifold itself has been sitting in acetone all day, and appears good, and the block/head passed the pressure test. had them sitting with about 10-15psi in them all day (issues around the pump kept bleeding off to about 10psi, where it would hold all day, no water in the cylinders, or oil (oil level is right where I left it this morning) I pressurized it using my Stant Radiator tester with a full block and head of water to avoid pumping for hours....If it works on the automotive side for leak testing, it will do the same thing here.

 

[Rick Stephens]

Weld er up.

 

[ScottinAZ]

Weld er up.

iffin it werent on the inside, I would braze it up in a heartbeat. as it is, I have a very uniquely shaped anchor