Yanmar 4BY2-150 Ranger Tug Engine Alarm - Glow Plug question or other possibility

Diane Perry

Member
Joined
Aug 23, 2024
Messages
5
Location
Vancouver WA
Fluid Motion Model
R-25 Classic
Hull Identification Number
2010 25SC
Vessel Name
Mi Amor
I have a 2011 Ranger TugR-25SC with a Yanmar 4BY2-150 Turbo Diesel.

An engine alarm sounds upon starting with no code. My Yanmar engine diagnostic i5601E will not display a code by holding the far right button. After the engine warms up, I can turn the engine off, restart and there is no alarm sound.

I found a post on Tugnuts that the Glow Plugs caused a similar issue.

Can someone provide me a picture/diagram of where the glow plugs are located? I have removed the engine covers and can only see the fuel injectors but no glow plugs. Crossing my fingers that the glow plugs are not located under a valve cover/intake manifold etc. and are easily accessible.

Appreciate any help for a fellow boater.
 
We had to replace glow plugs on our 6BY2-260 last fall. Similar experience where we got the engine alarm with no code on the Yanmar panel. They are buried under the intake manifold. I ended up having a tech from Gallery Marine on Lake Union in Seattle change them out for me. I ordered the glow plugs from Diesel Parts Direct at about $95.00 each and then had Gallery take care of the install. After seeing them do the job, I probably could do it myself if I had to, but there is some comfort in having the pros to the job right the first time.
 
Thank you so much for your very helpful information. Upon re-inspection of the engine, I could catch a small glimpse of the #1 cylinder glow plug and yes, on my 4 cylinder engine, it appears to located under the intake manifold. Now trying to put together a gasket part list and glow plugs. I think I will also change out all 4 glow plugs so as to not have to go down this path again in the next 6 months.
Diane Perry & Wayne Coughran
2011 Ranger Tug 25SC
Vancouver, WA
 
I had a similar problem on my 2012 R25. I did get 4 separate error codes. One for each glow plug. I took it to a Yanmar service center in SC for the service but it turned out to be the relay between the glow plugs and the ECU.
 
I had a similar problem on my 2012 R25. I did get 4 separate error codes. One for each glow plug. I took it to a Yanmar service center in SC for the service but it turned out to be the relay between the glow plugs and the ECU.
We did remove the intake manifold and checked the om reading of each glow plug which was around .8 oms, within factory specs. We then checked each glow plug when energized. Can you describe where the glow plug relay is located? Or perhaps a part number? We could not identify or locate the relay.

These darn electrical problems can be very allusive. Our next plan is to put our boat back in the water to see how it behaves. Next step is our local Yanmar dealer to see if they can read a code. Thanks for sharing your experience.
 
We did remove the intake manifold and checked the om reading of each glow plug which was around .8 oms, within factory specs. We then checked each glow plug when energized. Can you describe where the glow plug relay is located? Or perhaps a part number? We could not identify or locate the relay. These darn electrical problems can be very allusive. Our next plan is to put our boat back in the water to see how it behaves. Next step is our local Yanmar dealer to see if they can read a code. Thanks for sharing your experience.
I looked at the 4BY2 Manual but could not find the Glow Plug relay. There are several relays in the ECU but, none were labeled Glow Plug Relay. I had an Yanmar service tech do the work.
 
Hi, we had a similar issue on our 2011 R-27 (4BY2-180) several years ago. An engine alarm would sound on a cold start and would go away after running for a few minutes as the engine warmed up. This behavior seemed to make sense after reading this page in the 4BY2 service manual (see below).
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There were some other articles on TugNuts about the same issue, the general advice was to disconnect the glow plug controller. After reading this page in the BY service manual, I decided this was the simplest path to follow. The boat has been running for 7 years with the plugs disconnected with no issues at all.
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Fair seas,
Brendan
 
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