[C320-list] Engine water temp problem

[Jon Vez]

Graham,
An easy way to test if the sender is good is to put it in a pot of water with thermometer and bring the pot to 170-180F and you can see it pop open if it's good.....

Sent from my iPad

> On Apr 8, 2017, at 1:18 PM, Graeme Clark <cg at skyflyer.co.uk> wrote:
> 
> Rick
> Thanks for the tip but the gauge does "climb" as the engine warms? it doesn't go straight to max reading!
> I haven't yet had a chance to troubleshoot further. Possibly tomorrow if it's fine weather as I want to start by cleaning up all contacts. 
> My gut feeling is the most likely reason for a problem is because of something I did rather than a random failure whilst the boat was laid up over winter  - it would be odd for a temp sender to fail when it sits in an unused engine for six months, surely!
> All options will be explored though!
> Graeme
> 
> Sent from mobile: please excuse typos etc.!
> 
> 
>> On 8 Apr 2017, at 15:34, Rick Sulewski <rsulewski at bex.net> wrote:
>> 
>> Graeme,
>> If you did anything with your wiring over layup you could have a sensor lead  grounding and pegging your gauge. For example, several years ago I had my valve cover off to adjust my Westerbeke valves and inadvertently pinched the temp sensor lead when the cover was reinstalled and that caused my temp gauge to peg.
>> Rick
>> 
>> -----Original Message-----
>> From: C320-list [mailto:c320-list-bounces at lists.catalina320.com] On Behalf Of Onat Dogruer
>> Sent: Friday, April 07, 2017 11:17 AM
>> To: C320-List at Catalina320.com
>> Subject: Re: [C320-list] Engine water temp problem
>> 
>> On a side note, I just replaced the 18 year-old Johnson water pump (with same model Johnson pump) on our Yanmar and the temperature is not going above 160. It used to hover around 170F. I wonder if they improved somehow the efficiency. 
>> -OnatKittiwake #546, 1998
>> 
>>     From: Allan S Field <allan.field at verizon.net>
>> To: C320-List at Catalina320.com
>> Sent: Thursday, April 6, 2017 2:20 PM
>> Subject: Re: [C320-list] Engine water temp problem
>> 
>> Our boat was about 10 years old when the temp sender unit failed.  A replacement was ordered from Yanmar for about $20 US 7 years ago and installed in about 10 minutes.  Problem fixed.
>> 
>> Allan S. Field
>> Sea Shadow - C387, #103
>> Columbia, MD
>> 
>> -----Original Message-----
>> From: C320-list [mailto:c320-list-bounces at lists.catalina320.com] On Behalf Of Graeme Clark
>> Sent: Thursday, April 6, 2017 1:14 PM
>> To: C320-List at Catalina320.com
>> Subject: [C320-list] Engine water temp problem
>> 
>> First time I run the engine this year the water temp gauge goes off the clock!
>> I therefore bought a point and shoot laser thermometer and sure enough the engine temp ( measured where the sensor is and also at fuel injector points) is around 170f whereas gauge is showing 280-290f
>> 
>> So it's the sensor or the gauge. How do I test the sensor.  There is only a single terminal so I'm guessing the resistance changes with temp. Does anyone know what resistance should be at say, 170f ?
>> 
>> Or is there a simple way to test gauge
>> 
>> I did have the instrument panel out this winter to repair the lid so it could be a dodgy connection I guess. I'll check everything again but any more info would be handy as I'm stuck on boat with limited internet access!
>> 
>> Graeme
>> #366, 1996 running Yanmar 3GM30F
>> 
>> 
>> Sent from mobile: please excuse typos etc.!
>> 
>> 
>> 
>> 
>> 
>> 
>