Merc T-Stat replacement? '96 3.0 lx

hi all,

had the boat out last week on our easter break and it ran well. i noticed around the last day that the temp guage died (wouldn't reg above 100). up to this point it ran about 120 which had never bothered me (better cold than hot i reckoned?) but i've read around the forums and research suggests that the t-stat may be stuck open. would it be likely that it had been failing and has now finally given up the ghost? i believe that the running temp should be around 150-160. my guage never went above 120 even under load at WOT.

my boat is 60 miles away so can't check until the weekend. is this most likely problem if the guage has always read low? i'm thinking of ordering one now so i can have it at the weekend, replace if necessary and get the boat out!

cheers in advance,

D.

Re: Merc T-Stat replacement? '96 3.0 lx

It very well could be the thermostat. Especially if you boat in salt water.

Re: Merc T-Stat replacement? '96 3.0 lx

as far as I know the boat has spent all its life on a lough in ireland. i've just ordered the t-stat kit and will replace this weekend. another question, when winterising in november i was able to pour antifreeze into the block thorough the t-stat housing via the hose that goes to the water pump. the boat had been out that day but (much earlier) and it air temp was very cold. would this be possible if the t-stat was closed or would you normally need to remove the t-stat to fill the block?

Re: Merc T-Stat replacement? '96 3.0 lx

Hopefully you made sure all the raw water was out before you started that process! And yes you should have removed the t-stat before adding the A/F and before even that you should have also removed all the drain plugs and then filled up to the level of each plug and then replace the plug after reaching that level not very complicated just filling up to the highest point and capping off.

Re: Merc T-Stat replacement? '96 3.0 lx

yup,

system was fully drained as per the merc instructions. i'm assuming that the t-stat was in some way open otherwise the AF would not make its way into the block and hence was/is faulty?

Re: Merc T-Stat replacement? '96 3.0 lx

Well,

I switched the thermostat and all is well. It seemed to have a positive effect on the warming up process (no surprise!!!!)