OPTIMAX eng temp

[LURCHER]

I have been having overheat warnings come up on my 150 Opti when revs are below 2500 as soon as rev go above this the temp starts to fall away rapidly . I had a new impellor fitted in the spring and have noticed the tell tale is not as stong as before however water pressure shown on Smartgauges is at 39 psi which is what it always has been . Any ideas ?

[Hugh Jardon]

mine warms to just short of 140, then drops to 118 then rises to 129 and controls between 118 and 129 with the thermostat opening and closing, noticed it today when flushing. cant help any further with what you have described

Originally Posted by LURCHER

I have been having overheat warnings come up on my 150 Opti when revs are below 2500 as soon as rev go above this the temp starts to fall away rapidly . I had a new impellor fitted in the spring and have noticed the tell tale is not as stong as before however water pressure shown on Smartgauges is at 39 psi which is what it always has been . Any ideas ?

[Searider]

Mine occasionally overheats at slow speed - 1600rpm and 6 knots ish. Not yet been able to sort it. Have beeb suggesed that it is the "middle poppet valve" whatever that is.
Turbodiesel - please help

[Paul F]

Go for the poppet valve, if thermostats are ok and block press.
Paul

[tim griffin]

There is a pipe behind the ECU that can bend when getting warm this can pinch and restrict the water flow . Check to see if this is the problem .

[Scotty]

Originally Posted by LURCHER

I have been having overheat warnings come up on my 150 Opti when revs are below 2500 as soon as rev go above this the temp starts to fall away rapidly . I had a new impellor fitted in the spring and have noticed the tell tale is not as stong as before however water pressure shown on Smartgauges is at 39 psi which is what it always has been . Any ideas ?

My 150 opti will drop to 95 when she's is moving at speed. And will go up to 150 ish or more at slow speed. Impellar replaced at last service (two hours of use ago). Maybe they are like my BMW bike....."They all do that sir !"

[LURCHER]

I haeding towards a poopit valve as my engine m,an has the same thoghts confirmed by Barrus so will report back .

[Searider]

Hi Lurcher,

When you get it done can you let us know what a poppet valve is please

[brucehawsker]

My 150 beeps overheat at this time of year at 6 knots on the Lymington River. Just go up to 9 knots for 100 metres and it is fine.