Snowball Effect (Part II)

When last I posted, I was writing about changing the oil in our 38 year old Perkins 4-108 diesel engine and explaining the inevitable chain reaction of events that are synonymous with nearly every project I tackle on this boat as of late.

I have to hand it to the previous owners of our boat.  Deep in the lazarette we found stashed a couple boxes full of new, and very useful spare engine parts.  Water hoses & water pump, v-belts, engine gaskets, fuel lift pump & diesel injector, oil & fuel filters, thermostat, a couple of raw water impellers and some pencil zincs for the heat exchanger.  Still haven’t figured out if their intention was to one day perform the necessary preventative maintenance, or just keep shit handy, drive it ’til it breaks, and then fix it. Or, just sell the boat and make it someone else’s problem?  I’m inclined go with the latter.  Not that I can speak to the fact that I’ve been on top of my game when it came to taking care of our diesel engine.  But then again, we haven’t exactly been using our engine, and I’ve been a bit preoccupied with doing things like trying to keep the rain on the outside of the boat, where it belongs.

A bunch of extra engine goodies that came with the boat

The actual draining of the oil went off without a hitch using our handy dandy West Marine oil change pump.  With a couple pumps of the handle a vacuum is created, drawing the old engine oil up through the dipstick tube and into the canister.  This thing works sweet and you don’t even have to keep pumping.  It has an automatic shut-off when it’s full, and I didn’t even spill a drop (remember that tidbit of information for later on in my post).  I decided not to refill the crankcase with new oil just yet since I needed to remove the remote oil filter adapter and oil lines on the rear of the engine in order to access the leaky heat exchanger for removal and inspection.

Raw water pump mounting face

So back to that dripping raw water pump…  I disconnected the pump hoses and drained the water, pulled the pump cover plate (again) and new impeller, and unbolted the pump from the front timing cover.  I tapped the pump shaft out of the housing with a hammer and pulled the offending shaft seal with a screwdriver and pliers.  The two shaft bearings (pressed into the housing) were in good shape, but the shaft was scored (just to the right of the deep groove in the picture below) where the seal had worn into the metal causing the leak.  I pressed the new (from the box of spares) shaft seal into the housing, cut a new gasket for the engine mounting face, and ordered a new pump shaft ($65) from Marine Parts Source.  I also ordered a new bronze cam as a spare, and a new impeller.  The impeller I installed from the spare parts bin wasn’t properly stored over the years, and it already showed signs of cracking after only running the engine for the 15 minutes or so that I warmed up the oil.  I’ll finish putting the pump back together when the new shaft is delivered…

Pump shaft scored from old seal
New raw water pump gasket

As for the heat exchanger, they sure didn’t stick it in a place that’s easy to get at.  I had to remove the oil lines and unbolt the remote filter mount.  Glad I had already drained the old oil and removed the filter before hand.  I also had to remove the stop/kill switch solenoid and disconnect the crossover pipes from the front of the engine in order to get to the last two hose clamps off the raw water side.  The exchanger housing has two drain plugs; one on the freshwater (antifreeze) side, and one on the raw (seawater) side.  The seawater side was already empty from working on the pump, but the freshwater plug snapped right off due to corrosion when I tried to loosen it.  Shit!  So with no way to collect the draining coolant in a controlled manner I had no other choice but to pull the lower cooling hose on the oil cooler and let a gallon and a half of antifreeze spill into the bilge.

Removing the oil filter adaptor
Removing the stop solenoid to reach the hose clamp hidden behind.

Pump output pipe to heat exchanger
Corrosion visible

With the heat exchanger finally out of the boat it was easy to see the crack where it was leaking salt water from the back side at the zinc fitting.  I’m guessing someone (not me) over tightened the zinc at one time and cracked the damn fitting!  I removed the end cap, and the cooling tubes didn’t look all that bad.  I probably could’ve taken it to a radiator shop, had it boiled out and the zinc fitting soldered up, but at that point I thought it prudent to just order a new one ($300 from Fisheries Supply in Seattle).  I read somewhere that “Loose lips sink ships.”  Recently, I read that a family from San Diego on a Hans Christian (Union 36) lost their boat 900 miles off shore due to a “leaky heat exchanger”.  Not sure which is worse, but I figured I’d change out the one variable that I have control over.

Heat exchanger removed
End view of cooling tubes

Zinc fitting cracked at housing

Bad engine mount

So once I had the heat exchanger removed, it became readily apparent the damage caused by the salt water drip, drip, dripping on to the port side engine mount below.  Rusted and corroded, herein lies the next phase of my repair…  You remember what I said about the snowball effect?  Now, it’s starting to make sense?  Stay tuned for part three when I autopsy the rusty and corroded engine mounts.  I’m surprised that the good ‘ol Perkins 4-108 didn’t just jump on out of the boat with those bad motor mounts, or worse yet, tweak the cutlass bearing where the prop shaft exits the hull.  Thankfully, the the water we’re floating in still remains on the outside of the boat.  Oh yeah, and I forgot to tell you about the oil I found floating in the bilge after I drained the coolant……

One thing leads to another
Of oil leaks and engine mounts