Engine Temp

Quick question. I have a 99 270, 5.7 EFI motor. The engine temp gauge will fluctuate from a max of about 170ish and then drop down to about 125. It seems to do this in a regular cycle. I don't know if this is normal or not, but my feeling is that it is not, but it doesn't seem to effect the engine at all. I'm just afraid that all of a sudden I'm going to over heat, or something worse. Any thoughts?

Comments

  • TikiHut2TikiHut2 Member Posts: 1,431 ✭✭✭✭✭
    Better check that impeller and thermostat. Could be an issue with your Faria gauges but it sounds like something you better figure out. You'll want to post what boat and engine type you have too. Good luck and let us know what you find. Mike
    2004 FV270, 300hp 5.7 350mag MPI Merc 305hrs, 2:20 Bravo3 OD w.22p props, 12v Lenco tabs, Kohler 5kw genset, A/C, etc.etc...
    Regular weekender, Trailer stored indoors, M/V TikiHut, Sarasota, Fl
  • BabyboomerBabyboomer Member Posts: 918 mod
    Mine stays at 170 

    Slip 866 Sunset Marina Byrdstown Tn
  • cmelt2003cmelt2003 Member Posts: 72 ✭✭
    Impellor is going on it's 3rd full year. I'm wondering if the thermostat isn't going bad. But I am also having some electrical gremlins that I have yet to resolve, but I doubt that it's connected. That has been discussed in a different thread.
  • BabyboomerBabyboomer Member Posts: 918 mod
    edited August 2013
    If the Thermostat was going bad it would stay open not getting up to temp or stay closed getting hot not letting water circulate If the Bravo was going bad it would be running hotter than 170 my guess is those (trustworthy good for nothing) Faria Guages

    Read This it tell how to check gauge

    Slip 866 Sunset Marina Byrdstown Tn
  • 212rowboat212rowboat Member Posts: 2,591 ✭✭✭✭✭
    stats fluctuate open and closed continuously... if it's hanging open when it should be closing, that could be your issue... stats cost what, ten bucks? and, its a ten minute job to swap them... test it in a pot on the stove before installing to make sure its not bad out of te box... seems lately in the past five years or so, ive seen more and more bad out of the box.. 

    it can't hurt to swap it, anyway.. 

    it could be your temp sender, too.. they operate on tiny voltage changes of 5vdc.. if the thing is shorting across the points where it registers resistance, which is internal to the probe, and also which is how they go bad, that could be what you're seeing... 

    that's too long on your impellor.... swap it!!! cost is maybe $75 total in parts including stat, and now you're up to an hour and a half of your time... 

    a
  • Michael TMichael T Member Posts: 7,227 ✭✭✭✭✭
    My money is an a sticking T-Stat. Have had this happen lots of times before - automotive and marine.  MT
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