My temperatures have been climbing up according to my gauge in the
cockpit to about 200 degrees.
We are cruising in
Mexico currently and are currently in
La Paz. Before we go further into the
Sea of Cortez, I want to fully understand what hte issue is.
Things I have done so far.
1. I replaced the fresh
water pump in Turtle Bay on the way down - the old one had play in the pulley - it wasn't leaking yet, but I didn't want to mess with it.
2. I replaced the
raw water impeller in the
pump because the old one was about 2 years old. The old one looked fine and I still get good flow through the system and out the
exhaust.
3. I unhooked all the hoses in the
raw water system and looked for blockages/pieces of impeller etc. Nothing obvious was found. While I had this apart I replaced the Zinc in the
heat exchanger.
4. I ran barnacle buster through the
heat exchanger and the overall system. This cleaned out the heat exchanger pretty well and I have a before and after shot for your reference.
5. I bled the fresh
water coolant at the petcock that is on the thermostat until
coolant came out of the bleed point.
A few things I have found.
1. The
oil cooler is shown plumbed into the raw
water circuit in the
engine diagrams, but mine is plumbed into the freshwater system on the exit of the heat exchanger. I'm not sure whether this is a problem as it has been like this for years while I lived in
San Diego. I did see in the manual where it says that the
oil cooler can be plumbed into the fresh or raw water system, I just thought it was strange since the other members of the tartan forum have their oil cooler plumbed into the raw water circuit. From the oil cooler in my system the coolant goes to the hot water
heater then returns to the
engine.
This is the section I found in the owners manual. However, the diagram in the manual shows different - See picture below.
9. ENGINE LUBE OIL COOLER:
Lubricating oil carries heat away from the engine bearings and other friction surfaces. The oil circulates from the
lube oil
pump, through the engine, through the engine oil cooler, and back to the oil pump. The oil cooler may be cooled either by engine fresh water or by sea water.
See below video for coolant routing.
https://youtu.be/asGEEyLi4T8
When running the engine under load the system seems to run in the 200 degree range according to the gauge (see attached picture). I run the blower and it seems to back down a bit. I shot the thermostat housing with an infrared thermometer and it is reading at about 180 which is where the thermostat is supposed to open, so I'm not sure whether I have an actual
overheating issue or not.
I am trying to find specifications on the temperature sending gauge so I can test it to see whether it is correct or not? Any insight on how to test this component? I've never done it before.
Any other thoughts on what to do to diagnose/debug?
Pics are below of the heat exchanger before
cleaning, the
exhaust elbow sea water input. Diagram of the
cooling system.
Will do another post with pics of the heat exchanger after runnign barnacle buster.