HEAT EXCHANGER LEAK

I HAVE A 4 INCH MERCRUISER HEA

I HAVE A 4 INCH MERCRUISER HEAT EXCHANGER THAT IS LEAKING COOLANT INTERNALLY. COOLANT IS LEAKING INTO THE RAW WATER. CAN THSE BE REPAIRED OR IS THE ONLY OPTION REPLACE THEM.

"If it is over 5 yrs. old and

"If it is over 5 yrs. old and used in salt water I wouldn't waste any money or time on it. If not, and you are very lucky and the leak is near the end a good radiator shop may be able to do something for you. 99% of leaks are due to corrosion or freezing so it is unlikely it will last much longer if repaired."

I'll bet no one ever repla

I'll bet no one ever replaced the zinc that protects that unit? One of the most overloked anodes in boating.

Jeff

???? There'a a zinc on the

???? There'a a zinc on the heat exchanger?????

Chris

"Usually built into the drain

"Usually built into the drain plug in the raw water outlet end, bottom side.
Rod"

"Totally with Jeff and Rick on

"Totally with Jeff and Rick on this one.My guess is that it has weared out and the whole unit is very thin.Fixing this is only the start of many more holes to follow.Its St. Pattys Day, so its time to break out some more green."

"The tubes and tube sheets are

"The tubes and tube sheets are made from corrosion resistant material (like Nickel-Copper). The shell and sometimes the shell ends are made of steel, therfore the zinc anode in the drain plug.
It's more likely the raw water side was not drained and allowed to freeze.
If the leak is in a tube, the tube ends can be plugged. Generally, up to about 10% of the tubes can be plugged and still have enough cooling capacity to keep the engine cooled.
If the leak is on one of the tube sheets, it could be soldered or the tube end re-rolled.

But like the others said... cheapest, easiest, and most reliable fix is to replace the Hx."