03 135 optimax

[jeff otis]

I have a optimax and sometimes the overheating alarm goes off? I always have a stream of water coming from the motor. How do I know if my impeller is bad or maybe my t-stats? Thanks

[staylor]

If yes, then check both water pressure and temp for a bit to see what engine conditions cause the alarm. If not, then if you're idling for 7-10 minutes and the alarm goes off, it's usually the stats- the alarm goes off when temp gets to the 175 degree range or so. If its above 2500 rpm when it happens its usually the pump or a clogged poppet relief valve- and only a look at the gages can reveal which it is. If you've not had the pump impeller changed in the past 2 years then do this first. One last problem area is a water filter screen down at the bottom of the block on a small water line hose- this can clog from running in silty water. You need a shop manual to pull the parts to get to this filter if you don't want to go to the dealer.
Doug

[Paulski67]

I would give this board a try, it is a great source for Opti questions

http://bbcboards.zeroforum.com/zeroforum?id=53

For the impeller, it is suppose to be replaced every 3 years or 100 hours to my memory, not sure how to check your t-stats

pal