Yanmar 1GM Oil Pressure and Water Sensors

[Teknishn]

Hello All,
Purchased my little '81 Hunter 27 a few months ago online and had it surveyed prior to purchase (I am currently living abroad and am pre-planning for the boat's outfitting, as well as trying not to over-plan before I see the boat....that struggle is real people! ). In the surveyor's report he recommended adding gauges for oil pressure and engine temp, which is a naturally a good idea but was going to put it off until other things were taken care of.

However, today I was gifted 4 gauges by my employer on the yacht I am currently working on as they have 3x spares onboard for everything! That, and somebody ordered 3 sets of 12-VDC gauges to be installed in a 24-VDC system. So lucky me, I now have an oil pressure gauge, water temp gauge, and black water and fresh water gauges....all in Bar, Celsius, or Liters mind you, and also in German, but what the hey...free is good! (Being tri-lingual doesn't hurt either.)

My question here is: Does the Yanmar 1GM have sensors for oil pressure and water temp? I have the manual for this engine, but it appears to be pretty vague on this issue. Can anyone add some clarification? If the 1GM did not come stock with the sensors, how much of an issue would it be to add them?

Thanks in advance,
Fleming

[Mike_NC]

Originally, mine just had the standard oil pressure and water temperature switches for the alarms (switches, can not drive a gauge). The gauge sensors were added by installing "T"s where the original switches are located.

Mike

[Teknishn]

Thanks for that Mike_NC. Will have to investigate installing dual circuit sensors (VDO type) which have a terminal for alarms and one that is a sensor for driving gauges.

[a64pilot]

My 4-JHE had an internal wrenching plug in an oil galley I put the oil pressure sender in, and the thermostat housing had another plug that I removed and put the water temp sender in.
The oil pressure port was some unusual thread, almost, but not quite a 1/8" NPT, based on advice from a Yanmar mechanic I ran a 1/8" NPT tap coated with grease to trap any shavings in the hole and all was fine.
I left the original alarm switches alone

[Wotname]

Is it a raw water cooled 1GM or does it have heat exchange unit (i.e. fresh water in engine).

If it is raw water cooled, the temperature gauge you have won't be suitable. The raw water thermostat keeps the engine below about 60C to prevent salt deposits in the water jacket and almost all engine temperature gauges start about 70C.

[Teknishn]

Originally Posted by Wotname

If it is raw water cooled, the temperature gauge you have won't be suitable. The raw water thermostat keeps the engine below about 60C to prevent salt deposits in the water jacket and almost all engine temperature gauges start about 70C.

It's raw water cooled. The gauge that I've inherited starts at 40C (The gauges I've inherited are custom gauges for the yacht I'm working on). Tested it today on one of our Daimler Benz OM352's and works just fine when compared to an IR handheld. Thanks for that good info on the thermostat temp preventing salt water deposits. Didn't know that about the 1GM. Very much appreciated!

[Wotname]

Originally Posted by Teknishn

It's raw water cooled. ......

Here is an older thread you might find interesting to review - all about temperature gauges and alerts for raw water cooled GM series and the detail is more accurate as I am not going memory

http://www.cruisersforum.com/forums/...se-150040.html

[Wotname]

Originally Posted by Teknishn

It's raw water cooled. .....

And here is another post that be of interest to you. While it refers to a 2GM20, i'm 95% sure it is applicable to your 1GM.

http://www.cruisersforum.com/forums/...rt-149469.html

[Teknishn]

Thanks for the great info on the 1GM and the related posts. Was able to take a look at a 2GM today during during my lunch break on a derelict boat sitting in the marina where I'm working. Now that I have actually laid eyes on a Yanmar I am kicking myself for starting this thread in the first place . Doing what I have planned is too easy! (I'm used to working on larger marine engines...Mercedes/Daimler-Benz, MAN, Caterpillar, and Kohler/John Deere and Perkins Diesel/Generators.)

Not to berate the Yanmar because it is a proven diesel, just feels a bit like a "Lawn Mower" compared to what I'm used to working on. But I also know there are things which I don't know about the Lawn Mower as well. Which reminds me, due for adjusting valves on our Fischer-Panda emergency generator next week (Basically a Universal engine). Good practice for working on my 1GM I guess...and getting paid to practice is a bonus!

Thanks again for all of the great input!
Fleming