Temperature guage fluctuations

[Geofflennox]

Hi All
I have a 1992 sundancer 290 with a 7.4 litre mag.
My temperature guage is fluctuating between 130 and 180.
I have replaced the thermostat and the 2 senders, but it has made no difference.
Anyone have any ideas?

 

[Express 390]

Hi All
I have a 1992 sundancer 290 with a 7.4 litre mag.
My temperature guage is fluctuating between 130 and 180.
I have replaced the thermostat and the 2 senders, but it has made no difference.
Anyone have any ideas?

Have you checked the raw water impeller ? Also flush out the oil cooler with a hose you won't believe what gets trapped in there. I had A 93 290 7.4 With the Bravo 2
Good Luck and welcome CSR!

 

[mrsrobinson]

Have you used a laser temp gun to check to see what the actual temp is at the riser, manifold and thermostat housing? Could just be a wonky gauge.

 

[Jeff Delbuono]

My 1998 290 with twin 5.0 started to do same thing this year. Both ran at 170 last year. Changed manifolds, risers, flappers and boots. Now port is 170 and starboard is 130. But under power goes to 170. Then if im cruising not under a load drops back to 130. Weird. Runs great tho

 

[mrsrobinson]

Raw water impeller and/or engine water pump going bad.

 

[Jeff Delbuono]

That would make it run cooler. Figured it would go up. Not down

 

[Bt Doctur]

verify that you dont have a case of Bravoitis

 

[Jeff Delbuono]

Jesus. Did have same issue like that on a new alpha i got on my 240 sorrento. Everthing inside melted. Company sent me a new water pump and found it was a faulty impeller. That will ruin a weekend