5.7 Vortec Mercruiser , water ingestion.

[mr 88]

Recent purchase , had it over the winter , closed cooling system , anti freeze checked out to minus 20 . Put about 20 hours on her when she decided to mix the coolant with the oil . New risers and exhaust manifolds , no engine oil cooler . Pulled intake manifold , water jacket hole had more gasket maker on it than rest of gasket . Saw a little rust , but nothing glaring . Put new stock gasket on , water went almost directly into the oil . Researched and found Fel Pro sold a upgraded gasket , bought it , installed , coolant went in and after a 30 -60 second delay. Into the oil it went . Pulled heads , ( not factory as they were not stamped ) jugs all had water in them., unless at TDC . No visible cracks or tell tale rust signs on anything . Engine rebuilder is scratching his head on this one . Any suggestions or thoughts , much appreciated

 

[nola mike]

All cylinders with water? Full or half system? What style manifolds?

 

[Scott Danforth]

Was the coolant low? Or was it plain water mixed with oil?
Did you pressure test the glycol side?

What is the SWL to riser height? Is it above 14"?
Stock cam, or something else? If so, what
Correct base timing?
Are both flappers there?

 

[alldodge]

Something is not flat

 

[mr 88]

All cylinders with water? Full or half system? What style manifolds?

Yes , all cylinders had water in them . Full closed cooling system . Standard exhaust manifolds

 

[mr 88]

Was the coolant low? Or was it plain water mixed with oil?
Did you pressure test the glycol side?

OutWhat is the SWL to riser height? Is it above 14"?
Stock cam, or something else? If so, what
Correct base timing?
Are both flappers there?

Coolant was low , filled it with anti freeze which got sucked into the crankcase .
Did not pressure test .
Riser height is around 12-16" .
Stock cam.
Yes , correct base timing .
Straight inboard . One exhaust port , no flappers , except the one hanging on the end of the exhaust at transom . No water ingestion when coming off plane .

 

[mr 88]

Something is not flat

Wondering about that . Old gasket material was built up around the two water ports on intake manifold , almost 1/4" thick , rest of gasket had nothing on it . Did buy the upgraded Fel Pro gasket ,which had more meat than the plastic stock one . Also put a small amount of gasket maker around the water ports , just enough to cover any imperfections in the steel , like 1/64" ,not 1/4". Still leaked .

 

[Lou C]

I don't know if it was totally solved 100% but the Vortec engines both V6 and V8 had problems with intake gaskets leaking coolant into the cam valley and right into the oil. Sometimes you'll find pitting on the water inlet ports, that can cause leaks, but the sealing surfaces of the manifold should be checked with a flat edge and feeler gauges. 1/4" of sealer on water ports means that someone saw there was a problem, but might not have solved it.
Now coolant in the cyls is not from the intake, that can be from leaking head gaskets, or even the joint between the manifold and elbow, or cracks in the cyl heads.

 

[Scott Danforth]

Coolant was low , filled it with anti freeze which got sucked into the crankcase .
Did not pressure test .
Riser height is around 12-16" .
Stock cam.
Yes , correct base timing .
Straight inboard . One exhaust port , no flappers , except the one hanging on the end of the exhaust at transom . No water ingestion when coming off plane .

If your SWL to riser height is 14-16", you are good to go

12-14" is chance to hydrolock

Glycol getting drawn into the motor would be a bad gasket or other issue.

Drain the coolant and pressure test

 

[mr 88]

Heads are off now , so no pressure testing . Not hydro locked or even close to that , hull is a resto mod 1975 Mako Center Console 23' , designed for sporty water . Took her to inland lake in South Carolina ( for our retirement next March ) that doesn't get rough enough to have water ingestion when coming off plane . No problem when on the Atlantic or Lake Erie / Ontario.

 

[mr 88]

Upgraded gasket is the left one .

 

[alldodge]

Put a steel edge across the intake ports and use a feeler gauge

Might even put the head on a lath and try taking a couple thousandths off to see if it's flat