RWC Volvo Penta 5.7L GS Temp

[CascoBay]

What should this engine (2000 Volvo Penta 5.7L GS) RWC run at for a temp? I installed a 160 degree t-stat and I only see 130 degrees on the gauge, is this normal or do I need to get an IR gun out?

Before the original t-stat failed it would run at 175 degrees.

 

[Don S]

Re: RWC Volvo Penta 5.7L GS Temp

If it's actually 130? while running under load, I would venture to say your new thermostat is sticking open.

or do I need to get an IR gun out?

Not sure how you can verify the temp without one. Check the temp right at the base of the temp sender where it goes into the block.

 

[CascoBay]

Re: RWC Volvo Penta 5.7L GS Temp

Thanks, I just dug out the old t-stat (which came out in pieces) and after scraping the grime off it I see it too was a 160 degree stat, so at least I got the right one.

Also, my temp sender seems to be on the t-stat housing, not the block, am I wrong?

 

[CascoBay]

Re: RWC Volvo Penta 5.7L GS Temp

Just ordered an infrared temp gun and will post the results when I receive it.

One thing I realized, I took out my 6 gallon water heater and simply joined the in and out RWC loop that would warm the water up so I could bypass the heater. The hose came from the side of the block and joined the water pump if I recall.

Would this cause a low operating temp? I think this may be a problem as it is bypassing the t-stat.........

 

[Don S]

Re: RWC Volvo Penta 5.7L GS Temp

Yes. Just block them off, don't just make a loop.

 

[CascoBay]

Re: RWC Volvo Penta 5.7L GS Temp

I blocked off the water heater loop, ran the boat for 1/2 an hour at 3000 rpms and only got a reading of 140 degrees at the t stat housing with my infared temp gun, gauge is reading 130 degrees.

What else would be causing the low temp?

 

[CascoBay]

Re: RWC Volvo Penta 5.7L GS Temp

Should I now consider 140 degrees normal?

 

[CascoBay]

Re: RWC Volvo Penta 5.7L GS Temp

Should I suspect a bad t-stat or is 140 degrees normal from a 160 degree stat?

 

[CascoBay]

Re: RWC Volvo Penta 5.7L GS Temp

I replaced the "old" t-stat with a new one from a different retailer, same results, boat runs at 130-140 degrees.

What else would be driving down the temp like this?

I put the t-stats in a pot of water and they both open at 160 degrees as they should.

 

[Don S]

Re: RWC Volvo Penta 5.7L GS Temp

Do you have the thermostat installed up inside the thermostat housing and held in place with an oring as shown in the manual?

 

[CascoBay]

Re: RWC Volvo Penta 5.7L GS Temp

That is correct, I installed it into the housing with a new o ring to hold it in place.

Thank you for the help with this!

 

[Don S]

Re: RWC Volvo Penta 5.7L GS Temp

Run the engine under load and see what the temp goes to. Bet it's closer to 170?.

 

[CascoBay]

Re: RWC Volvo Penta 5.7L GS Temp

I will do it again and see what happens.

 

[CascoBay]

Re: RWC Volvo Penta 5.7L GS Temp

Temp while underway is 140 degrees via infrared temp gun, gauge reports 130 ish with the new t-stat.

I have another issue and will post it in another thread.

 

[CascoBay]

Re: RWC Volvo Penta 5.7L GS Temp

After running at 3000 RPM for nearly 2 hours here is the result:

Why on earth is this running so cold with 2 new t-stats?