Temp Gauge quick question

Post Reply
Pilotmike
Lieutenant
Lieutenant
Posts: 30
Joined: Sat Aug 17, 2019 11:51 am
Location: TN
Contact:

Temp Gauge quick question

Post by Pilotmike »

Last season the temp gauge read 160 during idle or no wake running. Under a load and running 120. Ambient water temp made no difference. Impeller is good (changed and checked)

Before I go digging too deep, your thoughts

I will check connections at the gauge terminal, then the gauge sending unit (on the 5.7 it's located at the thermostat housing correct)?, After this, then...?

Thanks

2001 246
5.7 GXI (B)
315 hours
2002 246 BR - 5.7 GXi (B)
User avatar
bruceb58
Vice Admiral
Vice Admiral
Posts: 1068
Joined: Tue Nov 24, 2020 11:10 pm
Location: Los Angeles
Contact:

Re: Temp Gauge quick question

Post by bruceb58 »

You can always double check your gauge by using an IR thermometer and aim it at the thermostat housing.

Not sure what thermostat is used in your engine but it will be either 160°F or 140°F. You may want to check its function.
2017 R5 350HP Mercruiser Bravo III
Northridge, CA
Big Bear Lake, CA
South Lake Tahoe, CA
User avatar
Big Block Power
Fleet Admiral
Fleet Admiral
Posts: 17904
Joined: Sat May 07, 2016 8:05 pm
Location: Neenah,Wi
Contact:

Re: Temp Gauge quick question

Post by Big Block Power »

Yea your tstat could be stuck open. Should be a 160. Some had 140s in them like mine does and they came out with a bulletin to change it to a 160 so the oil gets warm enough to get rid of moisture in the oil.
03Cobalt220 8.1gxi DP
"Kids in Tow2"
"Pot The Jus" Originator :-)
Neenah Wi
#ItsBu'sfault
#FARCON Marine CC Core!
Pilotmike
Lieutenant
Lieutenant
Posts: 30
Joined: Sat Aug 17, 2019 11:51 am
Location: TN
Contact:

Re: Temp Gauge quick question

Post by Pilotmike »

I will check the tstat, but this weekend the temp gauge never moved off of 100. This screams gauge or sender to me, but i'm not sure.
2002 246 BR - 5.7 GXi (B)
User avatar
Krob1114
Vice Admiral
Vice Admiral
Posts: 1794
Joined: Sun Jun 09, 2019 8:03 am
Location: Greer’s Ferry Lake, AR
Contact:

Re: Temp Gauge quick question

Post by Krob1114 »

I'm leaning on the thermostat stuck open.
Same thing happened to me on my Mercedes. Had no heat in the winter time.
2019 Cobalt R3 @ Greers Ferry Lake, AR
Home in Hernando, MS
Pilotmike
Lieutenant
Lieutenant
Posts: 30
Joined: Sat Aug 17, 2019 11:51 am
Location: TN
Contact:

Re: Temp Gauge quick question

Post by Pilotmike »

Forgot to revisit this with those who helped out.

The previous impeller came apart and I changed it out. After removing the T-Stat I found the remains of the impeller vanes in the T-Stat and throughout the housing. Solved! Thanks
2002 246 BR - 5.7 GXi (B)
User avatar
jhnmdahl
Vice Admiral
Vice Admiral
Posts: 1909
Joined: Tue Jan 06, 2015 5:11 pm
Location: Twin Cities, MN
Contact:

Re: Temp Gauge quick question

Post by jhnmdahl »

Thanks for the followup, PilotMike - it's sure to help someone else down the road
Administrator of the www.cobaltchat.com Cobalt boats community forum
2015 210 (Volvo Penta 5.7L V8-225)
Post Reply

Who is online

Users browsing this forum: No registered users and 0 guests