D4 engine zincs

[jeannieb]

Just checked my intercooler and oil cooler zincs. Both were completely shot after only 85 hours and about 4-5 month's service. Both had come apart in large pieces. I removed the aft plate to the intercooler and cleaned out the debris. Some of the lower core holes were blocked.

Any thoughts on the use of these zincs? Obviously, if they're deteriorating that fast internal corrosion is a concern. On the other hand, if they perform their job by breaking up in pieces large enough to block small cooling passages, well, that's also a reason for concern.

Anyone else experience any problems with these zincs? My last Volvo was a KAMD44 and though it didn't have any internal zincs, it didn't seem to suffer for the lack of them.

[backman]

mine were OK/400 hr's last year also

I specifically asked the mechanic and he said "no issues - came out cleanly"

FWIW - I almost never use my shore power and am in a location in my marina w/ no boats w/ shore power w/in 30' of me.

My stern sinc plate is always in good condition while the big boyz row has serious corrosion of their zincs by mid summer.

[TwinFin]

??

Larry - where are your zincs located on the D4's? As far as I know there are no zincs on my KAMD300's.

[jeannieb]

Engine zincs on the D4 are located in the aftercooler and oil cooler housings (end plates). Your operator's manual for your KAMD300 should show you where the zincs are located (if they're installed at all). My KAMD44 didn't have them.

I think my problem's the marina I'm in (stern and shaft zincs burn up pretty quick too).

Heads-up though...if my experience is any guide, those D4 engine zincs don't necessarily burn off smoothly.

[Bullish]

I'm fairly sure the KAMD300 doesn't have any zincs since my kamd 44p (basically the same engine) doesn't hav any.

[TwinFin]

there is

no mention of engine zincs anywhere in my Volvo manual. All I have is the big plate on the transom and my bonding system to tie everything to that plate. I go through 1 plate per year - 1.5 year and I'm always on shore power when I'm not running.

No shaft zincs either. I always get a bit paranoid when I see others with zincs everywhere.

[code blue]

D4 zincs

I change my zincs every 6 months on Q and they are about 75% gone then. You may have electrolysis issues where you dock, other boats not grounded etc....How are your genny zincs/hull and shaft zincs. I put about 200 hours on every 6 months give or take a few hours.

[jeannieb]

I'm sure it's the dock I'm in rather than my boat. Strong current through the slip and living next door to the Virginia Institute of Marine Science (with all their assorted electrical equipment, etc) is most likely the problem.

Some guys I know have pulled the engine zincs out of their motors, fearing they'll clog a cooler when they break-up (rather than dissolving as they should), and they figure the risk of that is greater than any potential damage from electrolytic corrosion. As I mentioned, my KAMD44 didn't have any internal zincs...so maybe those guys have a point.

Guess I'll just keep it in mind, maybe check 'em every 50 hours or so...