Merc 3.0 ran into sandbar - temp gauge not working

[ramelton35]

Last trip out we hit a sand bar and on the way back to the trailer I noticed the temp gauge was not reading at all. Well I am sure it sucked up some sand, so what do I need to do to flush the cooling system sand out, as well as fix the gauge so it reads the engine temp.

 

[nola mike]

Can't think of a reason why hitting a sandbar would take out the temp gauge, unless you're not getting any water to the temp sender...and you're actually severely overheating.