View Full Version : Does your temperature guage fluctuate a lot?

06-02-2014, 05:15 PM
On my 07 LSV with a 325 Indmar engine I seem to get a lot of fluctuation on the temperature gauge and wondering if maybe my thermostat is starting to go bad. It usually stays a little higher than the 180 line (usually on the "0" of the 180) but every once in a while I will glance at it and it is getting closer to the 240 mark as I am just sitting with the boat in neutral. Then if I put it in gear and drive it will move back to the 180 mark and stay there. Seems to be random. Anyone else have this problem? I might just replace the thermostat to be safe but have no idea where it is. Is this an easy DIY? Any thoughts would be appreciated. Thanks.

06-02-2014, 05:47 PM
I would also check my impellor.

06-02-2014, 05:48 PM
How old is your impeller? Check all your clamps on the draw side of the impeller for air leaks

06-02-2014, 06:59 PM
Scott - mine was acting the same way first thing last year. New impellor + new thermostat. All is well again and it stays between 160-180 as expected. I'm not the type to change it every year whether it needs or not, but to me that was the indicator that it was time.

"Sorta" easy DIY but the impellor can be a PITA to get out. Mine was about a 2 hour 2 beer job since it didn't seem to want to budge. Can be done with ordinary needle nose pliers and patience though - no special tools required, although they do exist. There are some threads on here, possibly in the archives section, with tips and tricks to make removal easier.

Skidim.com - about $60 total unless you can find what you need local - good investment for peace of mind.

06-02-2014, 07:04 PM
Thermostat indicated by Red.

Impellor (Blue) is going to be on the front of the engine (back of the boat) under the exhaust muffler. Not as easy to get to which makes removal a pain.


06-02-2014, 11:34 PM
Thanks guys, the impeller is new just a month ago so I should be fine there. I will check all the clamps around the housing. I will probably order the thermostat just for peace of mind. Thanks bergermaister for the picture, my impeller wasn't bad to change at all with a little wd-40.

06-03-2014, 08:32 AM
Best tip I heard is to bump the engine to help loosen it. I can usually get it out in about 5 min. now.

06-03-2014, 08:41 AM
my engine temp bounces around when my water strainer gets clogged

06-03-2014, 10:23 AM
I did clean out the strainer last night to make sure. It had a little bit of stuff in it but not much. There was A LOT of debris in the water so maybe something was over the intake on the bottom of the boat and that is why it started getting warm while we were just sitting in neutral and the temp came down when the started moving and the debris cleared away from the intake. Hopefully that is it. I think I will still get a thermostat and keep it handy just in case. Anyone know the part # off hand?

06-03-2014, 11:37 AM
whenever I hit shallow water (canals especially) my filter will temporarily get clogged with weeds and the temp gauge goes thru the roof. When I hit deep water and get back up to speed (35+) all is well.

Having an extra thermostat is a wise idea.

06-03-2014, 12:00 PM
in addition.....

My trusted Moomba dealer (no longer in business) always told me to replace the impeller once a year.

I always did that and was glad I did.

06-03-2014, 01:53 PM
I just changed my thermostat after having my temp gauge bouncing between 180-240. I ordered it online at Bakes. The bottom gasket, which I forgot to order, was at Napa for $0.94. I didn't bother with the impeller since it was changed in April. I hooked up to a fake-a-lake after installing the new thermostat it is appears all is well. We will find out next weekend when I get out to the lake.

Product ID: 985009
Product Name: Thermostat 160 Degree Marine Indmar Standard
Attributes (if any):
Price: $16.50
Quantity: 1
2. Product ID: 531058
Product Name: Gasket Indmar Thermostat 3 Bolt Housing
Attributes (if any):
Price: $4.50
Quantity: 1

06-03-2014, 02:12 PM
thanks for the part #'s. I will swing by the dealer and pick it up.