Posted by lance_ryley (lance_ryley@…>)
You know the zinc in the heat exchanger? I didn’t. One of Don
Casey’s articles pointed out that I should check that, and since I
didn’t know about it last year, and since I had all kinds of other
engine issues last season, I figured I’d better take care of it. I
took out the plug and lo and behold, the zinc (or at least what was
left of it) was still in the exchanger! Since I could either a) hang
upside down over my perkins and try to dig it out for an hour or b)
remove the heat exchanger and work on it in relative comfort, I
decided to remove it, and while it was out, have it professionally
cleaned.
Lesson 1: Close the intake seacock before starting work on the
exchanger. (I remembered to do this one).
Lesson 2: Drain as much of the coolant from the engine as possible,
preferably not by cracking off the hose on the exchanger inlet and
letting it spill into the under-engine pan. (Sigh… a small bilge
pump and a 5 gallon bucket later, it took a while to find a place to
dispose of the mistake. pumping it into bottles in the first place
would have been a much better idea.)
Lesson 3: At least on the Perkins 4.108, REMOVE THE OIL FILTER
before removing the heat exchanger, even if you just did an oil
change the month before and the filter is brand new - trust me. You
may be able to get the exchanger out, but it will not go back in.
Nope. at least, not without lubricating it liberally with knuckle
blood.
So I got the exchanger out, and 4 days later, I had a nice, clean,
presumably more efficient exchanger that had a brand new zinc (plus
one spare) and a lovely primer coat pre-applied (Holt, Inc., Saugus
MA - $100, great guys). I ran down to the local AutoZone, bought
some Krylon engine paint and had some fun turning it blue. I let the
paint set up for a day and then decided to install it.
Lesson 4: See lesson 3. Really!
Lesson 5: Why does a hose clamp cost $1.00 at Home Depot? I replaced
any that were in the least bit suspect.
I poured about a gallon of antifreeze into the engine, crossed my
fingers, and vroom off I am to the races. I do a quick clamp check
to make sure nothing is loose, and everything looks good. I shut
down the engine before it gets too warm, so I can crawl back in the
space and check again. So far, so good. Everything looks tight, and
so I went to sleep, content that I’d done a fine job.
The next day after work, I decided to start the engine again and
revel in my mechanical aptitude. All went well, until the funny
smell started to fill the cabin.
Lesson 6: Funny smells are rarely good news.
I looked into the engine room compartment and the engine was smoking
all over. As I rushed into the cockpit to kill the engine, I glanced
at the temperature gauge, which had pegged well above the 240 deg.
topmark. Needless to say, I was having a bit of a freakout session,
wondering how many years I had just taken off my poor, long-
suffering, 25 year old Perkins. A quick check of the bilge didn’t
show any coolant, so yet again I hunkered down over a now-very-warm
engine and checked for leaks. Bingo! The outlet from the heat
exchanger to the oil cooler was leaking. Easily fixed. When the
engine cooled sufficiently, I cracked the top of the coolant
reservoir and to my GREAT surprise found it nearly empty.
Lesson 7: If you have the manual, read it. Maybe you’ll learn
something, maybe you won’t. But some poor sot took the time to write
down things he thought were important, so the least you can do is
take a gander.
In my case, looking at the Perkins manual revealed that the engine
holds 2 gallons of coolant. I had barely put in one gallon, but that
had filled the reservoir, so I naively believed it was… filled.
Nay, nay. Those of you with engine experience will know that the
engine needs to be “burped;” (who knew that engines were so very
much like fussy children?) essentially, the thermostat must open and
allow the coolant to flow into the engine. And flow it did, creating
the space in the reservoir for the extra gallon of coolant.
Having added that extra gallon, I again tested the engine. This test
resulted in no leaks, a constant level of coolant, and an idling
temperature of approx. 130 degrees - quite good for an engine known
to run hot in the first place.
Some of you will read this and chuckle, thinking “I’ve been there.”
Others of you will shake your head and wonder how such a damn fool
got to be a boat owner in the first place (in the US, all it takes
is Money ;). I don’t care - I know I’m bumbling through. If there’s
a lesson 8, I think it’s “do your homework,” and to paraphrase Dan
Quayle, be prepared for any contingency which may or may not occur.
(whew,that’s a lot of preparation!). I hope at the very least that
my little tale will save someone some little bit of heartache as
they commission for the Spring. And hopefully, I’ll see some of you
out on the water!
Lance
S/V Bright Star