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Nissan 50 TLDI problems (help!!)

littlejpeppers

New member
I have a Nissan 50 HP TLDI outboard motor. I really have nothing bad to say about the motor but I have an issue, I don't have much water coming out of the pee tube (tell-tale). I have taken the tube off of the motor and I can blow air through the tube so I know it isn't stopped up. Whenever I am running the motor, the water just dripples out of the tube. I can rev the motor (say 2000-3000 RPMs) and I can get a little more water, but not to the amount and pressure that I am used to seeing from an outboard. I have taken the boat out once so far and it isn't overheating, at least not according to any alarm. The water that is coming out of the tell tale is warm, almost hot, which would leave me to believe that the motor is getting hot, maybe almost too hot (??) and the alarm is functioning.
Now, to check things out, yesterday i removed the lower unit and looked at the water pump and impeller. This motor doesn't have many hours (maybe 50 or so) but is is about 4 years old. The impeller looked fine to me (no cracks or really high wear marks) so I reinstalled it and tried the motor again. I did put water and air though all of the water lines that I can see and I don't see where I have any type of blockage. I checked the thermostat, it opens like it is supposed to. The thing that gets me is on the right side of the motor, where the water line ties into the air compressor (??). The water going into the air compressor is cool but when it leave the air compressor from the bottom (the tell-tale tube) it is really warm, almost hot. Could it be that the water pump is working, just not pumping quite enough??? I am almost to the point where i am going to purchase the water pump kit and try that. Any help would be greatly appreciated. Please. Thanks.
 
There isn't any way to tell what problem, if any, you may actually be having without visually seeing the engine running and performing the relevant diagnostic procedures. Replacing the water pump would always be the first step as the water pump is 100% always replaced anytime you drop the lower unit. You might want to get the engine into a certified Nissan/Tohatsu dealer as the engines onboard diagnostic software can tell you virtually everything there is to know about how and why the engine is running a certain way.
 
Thanks Guru, I did take the motor into a Nissan tech/dealer last year with the say problem (no alot of water from the tell/tale). They told me that they check everything out and nothing seemed to be a problem. I don't know, i just don't like the amount of water that i actually have coming from the tell/tale. I have owed quite a few outboards and I know that with this motor, the last two years I haven't seen the amount of water that I think should be showing from it. I am going to replace the water pump tomorrow and hopefully that will help. I do have two follow up questions though.
First, when i took down the lower unit and water pump, i put water though the lower unit to see if I had good flow coming to the bottom of the water pump, which i did. But, on the starboard side of the water pump, on the bottom of the water pump housing, their is a "pin hole" that lets water come out of the bottom end of the housing. Is this "pin hole" supposed to be there? Also, do you know if the air pump is supposed to get pretty warm while the engine is running? I am hoping that maybe the water pump isn't pumping enough water and in turn, the air pump is getting too hot... make any sense? This air pump is new technology to me so not really sure. If the "pin hole" isn't supposed to be there, that might be the whole issue? Thanks in advance
 
The hole allows sand to escape...It allows your water pump to clean itself of debris. The pump should get raise in temp, but it shouldn't get hot enough to burn you. It is possible that you could have a build up of lime, salt etc., that can cause the air pump to fail. If you use the engine in salt water and don't flush it I would say you are at the beginning of it failing.
 
I changed out the water pump with water pump kit this weekend and it seems to be a lot better. The Nissan tech told me to not expect as much water for the pee tube as you would see in other motors, for some reason the 40/50 TLDI's just don't have as much pressure. But, with replaceing the water pump, i now have water from the pee tube and at least it makes me feel better.
Thanks for your comments Guru
 
Hi there littlejpeppers... just want you to know I just bought the Tohatsu 50 TLDI MD50B2EFTOS... I read your post with interest, I agree with you, even brand new the amount of water I'm seeing is somewhat less than my experience. But some motors have a small passthrough from the motor to the outside that constricts and really throws out a long tale stream. Thats exactly what a former Merc40 had, which contributed to many small debris clogs at that pinch point.
 
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