I would like to add a temp guage to our yanmar 2gm20f (don't worry, I wouldn't think of disconnecting the warning buzzer). What is a good way to install it? We have an engine heated hot water tank with a coming and going hot water hose to it, if this is a good place to put the sensor. Any ideas? Also, what should the optimum cruising temperature be at 70-80% max rpm? Thanks Doug
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Temp. Guage Installation
Doug, Installed a temp gauge on exactly the same setup on our 1999 H310. The only satisfactory place I coul come up with is to T it into the heating line GOING to the hot water tank. Be sure to use a brass T and ground it to the engine block. Our normal temp. at 2600 RPM is 175 deg. F. but these gauges are not noted for being terribly accurate. The importnt thing is to notice if it varies from what you normally see. Regards, s/v Island Hunter
Doug, Installed a temp gauge on exactly the same setup on our 1999 H310. The only satisfactory place I coul come up with is to T it into the heating line GOING to the hot water tank. Be sure to use a brass T and ground it to the engine block. Our normal temp. at 2600 RPM is 175 deg. F. but these gauges are not noted for being terribly accurate. The importnt thing is to notice if it varies from what you normally see. Regards, s/v Island Hunter
Thanks for not disconnecting the buzzer.
Doug: There are several options here. One is to purchase the new panel from Yanmar (expensive). Another option is to put a T in the position where the sensor exits the block. I had instruction on how to do this but have mis-placed them. There is a problem with the threads being BPT (british pipe threads not tapered I think) and they need to be re-tapped. Anyway you can just purchase a Stewart Warner or other brand of guage and have the buzzer sender on one side of the tee and the guage sender on the other. Then run the wires to the guage and you've got it. This is similar to the oil pressure setup, but the person I spoke to recommended that we move the pickup to a place where it could be mounted in a solid position so it did not get knocked off and broken (very small fitting). In both cases it required that the threads needed to be re-tapped.
Doug: There are several options here. One is to purchase the new panel from Yanmar (expensive). Another option is to put a T in the position where the sensor exits the block. I had instruction on how to do this but have mis-placed them. There is a problem with the threads being BPT (british pipe threads not tapered I think) and they need to be re-tapped. Anyway you can just purchase a Stewart Warner or other brand of guage and have the buzzer sender on one side of the tee and the guage sender on the other. Then run the wires to the guage and you've got it. This is similar to the oil pressure setup, but the person I spoke to recommended that we move the pickup to a place where it could be mounted in a solid position so it did not get knocked off and broken (very small fitting). In both cases it required that the threads needed to be re-tapped.
Metal Fatigue Factor
One of the problems with adding brass fitting onto the block, ones that stick out, is the constant vibration the diesel makes and the possibility of metal fatigue. The fittings for oil and water have a fairly small thread and by the time one adds a block and a couple senders the mass which is leveraged out becomes significant when compared to the small threads. And since the threads are a "V" they have a built-in start point for a failure. At least this was how it was explained to me by a person knowledgeable about marine engines, and it seems plausible. For this reason I went with the sender in the hose setup and it works find. The good side to this solution is one doesn't have to worry about matching threads. Just something else to consider - the joys of boating.
One of the problems with adding brass fitting onto the block, ones that stick out, is the constant vibration the diesel makes and the possibility of metal fatigue. The fittings for oil and water have a fairly small thread and by the time one adds a block and a couple senders the mass which is leveraged out becomes significant when compared to the small threads. And since the threads are a "V" they have a built-in start point for a failure. At least this was how it was explained to me by a person knowledgeable about marine engines, and it seems plausible. For this reason I went with the sender in the hose setup and it works find. The good side to this solution is one doesn't have to worry about matching threads. Just something else to consider - the joys of boating.
Good idea.
John: That is a good idea. Makes the installation much simpler too. What do you do about the oil pressure? Any suggestions?
John: That is a good idea. Makes the installation much simpler too. What do you do about the oil pressure? Any suggestions?
My Oil Pressure Sender "Fix"
For the oil pressure sender I used a VDO sending unit with two terminals and the lowest "make point" available with the particular thread required to replace the Yanmar oil pressure sending unit. This was several years ago and I don't remember the details. Finding out what the required thread was was really difficult. What I remember was the shop manual appeared to have a conflict as to thread type depending on what diagram you looked at. The thread I used was extreemly close, but I don't think exact, the same as the Yanmar thread. The softer metal of the VDO sending unit, brass?, compared to the cast iron engine block, allowed for use without damage to the block. Both the alarm on the Yanmar panel and the gauge works. Ditto for the watar gauge.
For the oil pressure sender I used a VDO sending unit with two terminals and the lowest "make point" available with the particular thread required to replace the Yanmar oil pressure sending unit. This was several years ago and I don't remember the details. Finding out what the required thread was was really difficult. What I remember was the shop manual appeared to have a conflict as to thread type depending on what diagram you looked at. The thread I used was extreemly close, but I don't think exact, the same as the Yanmar thread. The softer metal of the VDO sending unit, brass?, compared to the cast iron engine block, allowed for use without damage to the block. Both the alarm on the Yanmar panel and the gauge works. Ditto for the watar gauge.
Cruise Temperature 160 - 165 Degrees
The temperature range will be between 160 and 165 degrees in the Northwest with fairly cool water. Also, as the mixing elbow starts to clog up and become restricted you should notice some/more "steam" comming out of the exhaust at the higher 80% power setting, assuming the impeller is good and the inlet water passageway is clear and no serious headwind or sea.
The temperature range will be between 160 and 165 degrees in the Northwest with fairly cool water. Also, as the mixing elbow starts to clog up and become restricted you should notice some/more "steam" comming out of the exhaust at the higher 80% power setting, assuming the impeller is good and the inlet water passageway is clear and no serious headwind or sea.
2GM20F Gauges
Several years ago with help from a Yanmar mechanic I installed water temp and oil pressure sensors to the 2GM20F on my 30T (1991) and they work great. Also left the buzzers in place. I have installation instructions, photographs and wiring diagrams I can send to anyone who wants them. Send me e-mail to roynjean@home.com with name and mailing address and I will mail them in about two weeks when I get home. Leaving tonight for New York City & Bermuda (Cruise ship - not my 30T).
Several years ago with help from a Yanmar mechanic I installed water temp and oil pressure sensors to the 2GM20F on my 30T (1991) and they work great. Also left the buzzers in place. I have installation instructions, photographs and wiring diagrams I can send to anyone who wants them. Send me e-mail to roynjean@home.com with name and mailing address and I will mail them in about two weeks when I get home. Leaving tonight for New York City & Bermuda (Cruise ship - not my 30T).
Roy, post them on the photo forum
Roy: This would be great. Why don't you just post this as an article on the photo forum when you return. It would be very helpful.
Roy: This would be great. Why don't you just post this as an article on the photo forum when you return. It would be very helpful.
Sorry I Can Not Do It
Sorry I can not post my pictures as I do not have a scanner. In the future I plan to get one but for now I am just sending my "package" (eight pages) to whoever asks for it. In the past year in response to previous HOW postings I have mailed it to eighteen 2GM20F owners, several of whom have informed me they made the installations and have been pleased. So, for now I just have to send via US Mail.
Sorry I can not post my pictures as I do not have a scanner. In the future I plan to get one but for now I am just sending my "package" (eight pages) to whoever asks for it. In the past year in response to previous HOW postings I have mailed it to eighteen 2GM20F owners, several of whom have informed me they made the installations and have been pleased. So, for now I just have to send via US Mail.
Roy, I just bought a VERY nice scanner for $79.
Flatbed scanner, serial plug & play..no card to install. There are a bunch of 'em in that price range now, and they all do a great job with pictures...come with image editing software, OCR--everything you need. So get thee to CompUSA or Best Buy or Circuit City and let's see your pictures!
If it weren't for my boat and my computer, I don't know what I'd have to spend any money on!
Flatbed scanner, serial plug & play..no card to install. There are a bunch of 'em in that price range now, and they all do a great job with pictures...come with image editing software, OCR--everything you need. So get thee to CompUSA or Best Buy or Circuit City and let's see your pictures!
If it weren't for my boat and my computer, I don't know what I'd have to spend any money on!- Status