Volvo D9 After Cooler weeping fresh water

[mikehar]

I am curious to see if anyone one here has insight into my problem. Last week I noticed that my charge air cooler (after cooler) was leaking water through the weep hole. It turned out to be fresh water, but we pulled it off, changed gaskets, pressure tested it and reinstalled it. The mechanic says that it is condensation. It’s still happening and it’s a good amount of water. My previously dry bilge is wet now. This can’t be right.

I am 99% sure it wasn’t like this before. Any thoughts on what might be causing an usual amount of condensation in my after cooler? The humidity is 58% today.

 

[Tired Trawler]

Greetings,

The weep or telltale hole serves three functions:

(1) To allow cooler core condensation to drain from the housing & prevent water buildup from reaching the cylinders. If you take a soft drink can out of your fridge & observe it a few minutes, does condensation appear? The aftercooler produces a far greater amount of condensation, especially if the raw water is cool.
Usually in my area the condensation spits out, not a steady stream.

(2) To give the operator an indication of cooler core raw water leakage, if you are running in saltwater, just taste the leakage & if its salty you probably have a leak. Leakage is usually a fairly steady stream.

(3) If you start noticing a black oily discharge, it usually means its time to service the turbo & clean the airside of the cooler core.

One last comment, the weep or telltale holes should be checked every service to confirm they are open & not restricted.

Hope this helps.

 

[mikehar]

It makes it harder to keep a dry bilge...

 

[DavidM]

It is supposed to drip, but only if it is freshwater. Maybe it was previously plugged and the condensate got blown through to the engine and somehow was recently unplugged. If fresh, not all bad as many engines, all Yanmar’s AFAIK, don’t have condensate drains.

David

 

[sunchaser]

Mike
The primary purpose of a condensate drain is to ascertain if salt water is present vs fresh water. Some marine after coolers have a valve at the “weep” hole that allows drainage only during a shutdown check. Or to check for AC salt water from time to time during a normal ER check while cruising.

On the NM engine is the weep hole threaded? Is so install the original intended valve. Volvo should be able to provide some insight too.

Love the NM 64 BTW, it is a very well thought out vessel.

 

[Tired Trawler]

Greetings,
I am not aware of any Volvo Penta aftercooler weep hole / telltale being threaded or having a valve, I am aware of an incident in the past where a well intentioned idiot plugged the hole.
The aftercooler filled with raw water on the airside, got into the intake manifold, then into the no.4 cylinder, water does not compress, no.4 connecting rod came out thru the side of the block.
I still have this engine in my collection.
A little background, I am a retired Volvo Penta dealer / master mechanic, 52 years exclusively on VP.
Hope this helps.