3.7 mericruiser exhaust elbow raiser leaking coolent into motor?

[CrAzYsEaN]

Ok so I was out on the water last weekend and I noticed my temp was starting to get a little warm, jumped up to about 200ish. So I stopped and we went swiming for awhile. Before leaving I opened up the coolant resevior (on top of the exhaust elbow) and couldnt see any coolant, checked the oil and everything was good, it was totally clean oil still. I poured a whole gallon of coolent into the tank and it just dissapered right away. So I started it back up and headed to the dock, no overheat on the way back at all. When i got it home i checked the oil and there was definitally coolant mixed at that time also noticed corrosion in the exhaust elbow/resivor tank. Pulled it off and its rotted through so the coolant was going down through the exhaust mainifold when i was pouring it in the motor.

I have two questions. First is it possible for the coolant to make its way to the oil through the exhaust mainfold at all? or i might just be looking at a bad head gasket?

Second, I am trying to order a new tank and they sell ones for a aluminum manifold or a cast iron manifold...what is the easiest way to tell which one I have..the elbow/resivor i have is black and reallllllly heavy. I see a black one online but it says for an aluminum manifold but wouldnt aluminum be alot lighter than cast iron? the other one they sell is grey in color and for a cast iron manifold anyone know which one i need to get?

**also my motor is an 1989 mericruise 3.7 liter if that helps at all**

Thanks for your time reading this, sorry so long just confused

 

[GLENN M]

Re: 3.7 mericruiser exhaust elbow raiser leaking coolent into motor?

Yes i had a 351 w and i filled crancase with water when my exhaust manifolds rotted out

 

[bigdad390]

Re: 3.7 mericruiser exhaust elbow raiser leaking coolent into motor?

Yes, once the engine is shut off, water can leak into the engine through any open exhaust valve. With the engine off, there will nearly always be at least one open exhaust valve. Once the water gets past the valve, it can leake past the piston rings directly into the crankcase.

 

[CrAzYsEaN]

Re: 3.7 mericruiser exhaust elbow raiser leaking coolent into motor?

can the antifreeze mixed with the oil do much damage if only ran for a short period of time? My plan is to replace the elbow and drain all oil and re-fill...could there have been any other damage done by the coolant mixing with the oil? The motor still ran VERY strong when i got it back to the dock, but I havent even attempted to start it since that day because I dont want to hurt anything else.

 

[zbnutcase]

Re: 3.7 mericruiser exhaust elbow raiser leaking coolent into motor?

Your 89 should have an aluminum manifold, just use a magnet to confirm. All tank/risers are iron and heavy.