Paul D,
As you probably know, and maybe some don't realize, thermostats are available in various degree settings. They usually come in 10° F increments, or thereabout.
You say that you put in a new thermostat and you still run cold. Could it be that you were running too cold a thermostat and replaced the old one with a new stat of the same range? If so, I'm thinking that if you tried using a stat with a higher opening setting, your engine might run a little warmer.
I have seen stats right out of the box that were defective. There is a remote chance that your stat is out of calibration. I've found, through the years while working on boats, that anything is possible. If you can't find the trouble in the obvious ways, then it's time to check out what's not so obvious. Take nothing for granted.
This is the way that I check out the operation of a thermostat, or lack of it. I put the stat in a pot and fill it with water until it is covered by maybe an inch or so. Place the pot on a stove burner. If you have an immersion thermometer, place it in the pot and turn the heat on. I've used a candy making thermometer. Use any one that will read up to 200° F or more.
As the water heats up enough, the closed stat will begin to open. Make note of the water temp when it starts to open. The stat isn't like a light switch, either on or off. It will (should) modulate. As the water heats more, the stat will open more. Lets say that the stat is set for 190°. When the thermometer reads 190° F, you should observe that the stat is now fully open.
Turn the stove off. As the water in the pot cools, make note of the temp that the stat is fully closed. Also as important, make sure that the stat is fully closed. If it doesn't, get rid of it, it's useless. Almost every thermostat that I have seen has a built in by-pass so that there is always some coolant being pumped through it, even when it is cold and closed.
I've had good results using P B Blaster. Another thing I like to use is Liquid Wrench. I find that WD 40 isn't as effective. None of the penetrants will work if you have a solid coating of paint sealing what you are working on. Scratch or scrape off the paint between the cap screw and the housing. Give the cap screw or bolt a slight tap or two to help penetration.
Good luck to all.
O J
Question for CD-33 owners...
Moderator: Jim Walsh
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Oswego John
- Posts: 3535
- Joined: Feb 5th, '05, 20:42
- Location: '66 Typhoon "Grace", Hull # 42, Schooner "Ontario", CD 85D Hull #1
OJ,
Yes you are right about the thermostat and I did that very test when I was really checking this out and the thing worked fine. I also find that nobody had other thermostats with different settings. There is only one.
I then focused on the guage and tested that as per Calder's methods. It tested out functioning too so I only thought the wire could be inhibiting some voltage but when hooked up with new wire it tested the same.
As I said, the motor runs fine so I am working with it. After all was said and done I put my hand on the thing when running and it feels the right heat. As a better sailor than mechanic I try never to overlook the "feel" or "look" of things.
SO thanks for your thoughts, but this is a mystery I suppose I need to accept like the father son and holy ghost, who put the moustache on Captain Morgan or the green flash, know what I mean.
Paul
Yes you are right about the thermostat and I did that very test when I was really checking this out and the thing worked fine. I also find that nobody had other thermostats with different settings. There is only one.
I then focused on the guage and tested that as per Calder's methods. It tested out functioning too so I only thought the wire could be inhibiting some voltage but when hooked up with new wire it tested the same.
As I said, the motor runs fine so I am working with it. After all was said and done I put my hand on the thing when running and it feels the right heat. As a better sailor than mechanic I try never to overlook the "feel" or "look" of things.
SO thanks for your thoughts, but this is a mystery I suppose I need to accept like the father son and holy ghost, who put the moustache on Captain Morgan or the green flash, know what I mean.
Paul
Thermostat and engine temperature sensor
We recently had to replace the thermostat housing and flange that is mounted to the head on the universal 5424. Replaced the thermostat at the same time, and then monitored the engine temp. After noting that the engine temperature did not achieve the thermostat rating, I noticed that the temperature sensor was located above the thermostat in the section that returns to the resevoir on the exhaust manifold. In this location, the sensor will be detecting the temperature of the bypass flow, which should be less than the actual temperature being maintained by the thermostat. As a result, the temperature indication will vary based on the load on the engine and the seawater inlet temperature.
As an aside, replacing the t-stat housing flange was possible without removing the head. We needed to use a ratcheting box-end wrench to get at the lower-center bolt.
As part of this repair, we removed the expansion tank in the port locker as we no longer have the hot water heater. Less hose and complication, more space in the locker. Engine runs great and no trouble running with less water in the system.
Hope this helps.
As an aside, replacing the t-stat housing flange was possible without removing the head. We needed to use a ratcheting box-end wrench to get at the lower-center bolt.
As part of this repair, we removed the expansion tank in the port locker as we no longer have the hot water heater. Less hose and complication, more space in the locker. Engine runs great and no trouble running with less water in the system.
Hope this helps.
-
Oswego John
- Posts: 3535
- Joined: Feb 5th, '05, 20:42
- Location: '66 Typhoon "Grace", Hull # 42, Schooner "Ontario", CD 85D Hull #1
Universal 5424 Thermostat
Hi Paul,
I think that maybe you have the right idea. If your engine is running cool but it doesn't bother you any and you can live with it, don't fix what's not broken.
Just for information purposes, I believe that your engine calls for a 160° F t'stat. I think that v jasinski might be on to something. The water sampler for the temperage gauge, as well as the water temp to actuate the t'stat should reflect the actual water temp of the engine at the head.
When the water temp inside the engine water jacket reaches 160° F and climbing, the t'stat will begin to open. It should be fully open at about 20° higher, or around 180° F. The M-18 even tolerates up to 190°. Any temps higher than the high end indicates trouble of some sort.
For some interesting reading, go to:
http://www.boatfix.com/how/cooling.html
Good luck,
O J
I think that maybe you have the right idea. If your engine is running cool but it doesn't bother you any and you can live with it, don't fix what's not broken.
Just for information purposes, I believe that your engine calls for a 160° F t'stat. I think that v jasinski might be on to something. The water sampler for the temperage gauge, as well as the water temp to actuate the t'stat should reflect the actual water temp of the engine at the head.
When the water temp inside the engine water jacket reaches 160° F and climbing, the t'stat will begin to open. It should be fully open at about 20° higher, or around 180° F. The M-18 even tolerates up to 190°. Any temps higher than the high end indicates trouble of some sort.
For some interesting reading, go to:
http://www.boatfix.com/how/cooling.html
Good luck,
O J