Merc V135 oil reservior problems and water pump questions

[Fin-ster]

Hi all,
I hope you guys can help with this one. I have an '88 V135 v6 and it has a problem where after sitting for more than a day the oil reservior on the engine does not automatically fill from the external tank causing the alarm to go off. Last year I managed to get it to stop for the day by opening the covers of each tank in some order I can't remember. Has anyone else had this problem before and where would be a good place to start as I dont want to randomly start changing parts.
Now onto the water pump. I changed the impeller last year with the kit and everything worked great for the whole season until the day came to winterize and then it didnt spit like it usually did. When I started it on the rabbit ears it put water out the hole only when revved. It always used to spit water out of the exhaust port in a mist until it was revved. Now it does not do that and I got a few drips out of the bottom part of the cowl that is not easily removed, but the water jacket does not seem to be leaking externally. Should I change the impeller, or look elsewhere and can someone give me a better idea of how this whole system works with the two separate water outlets?
Thanks in advance,
Shane

 

[hkeiner]

Re: Merc V135 oil reservior problems and water pump questions

I can comment on the oil reservoir problem if the oil injection system on you motor is the same as the one on my motor...​

http://continuouswave.com/whaler/reference/mercuryOilInjection.html​

The first thing I would do is check whether pressure is building up in the remote oil tank. To do this, loosen the fill cap on the remote oil tank immediately after turning off the motor and listen for escaping air. If you don't hear any air escaping, then you probably have a defective one-way check valve (the one that feeds the air going in to the remote tank) or a big air leak somewhere. Even if you do hear air escaping, you may still have a defective check valve or air leak that results in some air pressure but not enough to push the oil up to the reservoir tank.​

Ideally, it would be nice to attach a pressure gauge to the system to monitor the air pressure level in the remote oil tank. Unfortunately, this is not very practical to do and Mercury does not provide a spec as to how much air pressure (PSI) should be in the remote oil tank under normal conditions anyway. Since you can't easily test the check valve with a pressure gauge, I suggest replacing the check valve regardless. It is not an expensive part and it is easy to replace. While I usually prefer to test/confirm components for failure before replacing them, in this case it is more practical to just replace this part to eliminate it as a possible cause. Also, the design of this check valve has been improved since your motor was built and having a new one with the latest design is a good idea anyway.​

Another area of potential problem are the filler caps on the remote oil tank and associated hoses. If they are leaking, then sufficent pressure may not build up and the oil will not be pushed into the reservoir at the engine. Finding and fixing these leaks is a little trickier when they are slow leaks.​

Another area of potential problem is the screen/filter located on the end of the feed line inside the remote oil tank. If it is plugged, then the oil can't be pushed out to the reservoir even if the pressure is OK in the remote oil tank.​

There are some more unlikely causes possible but I would start with the above items first.​

Good luck​

 

[studlymandingo]

Re: Merc V135 oil reservior problems and water pump questions

As to your water pump question...

Yes replace the impeller, and you should never rev the motor while on muffs.
​

 

[Fin-ster]

Re: Merc V135 oil reservior problems and water pump questions

Thanks for the help guys I got the water pump to work and when i released the pressure on the oil reservior tank(on engine) it filled itself. This leads me to believe that I have a pressure leak in the oil system. Also when I got it up on plane the first time it was fine but later in the day every once in a while it gave me an intermittent beep which if i remember correctly indicates and oil pressure problem. So I guess I should replace the check valve. Also how difficult is it to change the upper reservior cap?
Thanks again.
Shane