1997 Volvo Penta 3.0gs plkd - what is normal operating temperature?

[Blintzbug]

Hi All,

I've got a 1997 Regal LSR 1700 with a Volvo Penta 3.0gs, and at off-idle speeds, it runs at about 175 degrees. Once you get going faster it gets up to about 185-190. Is this normal? It used to run too cold (maybe 130 degrees max), and I discovered there was no thermostat installed. I purchased the recommended 160 degree Volvo thermostat, and now I'm concerned it's running hot. Last year I replaced the circulating water pump (it was weeping) and just last week the impeller in the sea water pump, thinking that might bring the temp down, so those two items shouldn't be a factor. Anyway, maybe 185-190 is normal? I can seem to find any information as to what's normal for this motor. Thanks!!

First-time poster, long-time lurker,
Sean

 

[Scott Danforth]

welcome aboard.

you are running hot

are you pulling your drive every year to check the u-joints? if so, are you inspecting your water inlet fitting?

 

[Blintzbug]

Thanks for the quick reply! The short answer is no, at least I haven't pulled the drive and inspected it this season. I purchased the boat last season and had a shop pull the drive to replace both the exhaust and u-joint bellows mid-season, but I didn't know about the running hot issue yet. It was running cold (and I figured the gauge or sender was shot). That reminds me, I did replace the sender and did some gauge testing with a thermometer and it seems to track well. I need to get myself an outdrive jack and build up the confidence to pull the drive myself and do what you suggest: check the inlet fitting, hose, etc asap. Is there a way to check it without pulling the drive? Not lazy, just don't have the means at the moment.

Here is a video of my temp guage while under way, just to illustrate exactly what I'm seeing:

https://youtu.be/p1ioDmDjkQc

 

[Blintzbug]

This old thread seems to imply that running in the 180's is normal? I realize it's a different year motor, so mine may be different:

http://forums.iboats.com/forum/engin...ng-temperature

But in this one, what Don says is in line with what you're saying, Scott.
http://forums.iboats.com/forum/engi...ives/579594-volvo-penta-3-0-water-temperature

 

[Lou C]

With a 160* stat, for my OMC 4.3 normal was 160-175 and the 175 was usually just after coming off plane, so I think your readings are too high. Have you ever taken off the exhaust riser to check the water passages? When they get clogged the engine can run hot....
​The gauge reading could be approaching 200*.Keep in mind for an open non pressurized cooling system, if the sending unit is seeing close to 200 the hotter parts of the engine could be seeing higher temps enough to boil un-pressurized water. That is why the thermostats are rated much lower than in a pressurized system where you have a 15 lb cap and that + the antifreeze raises the boiling point to about 265*.

​get an IR temp gun and take some readings

 

[Blintzbug]

Ok, I'll get a temp gun and take some readings. And I ordered a riser gasket and will pull the riser this weekend. I also ordered a 140 degree thermostat just in case, as here's my primary delima: next week we're renting a lake house for the week and would really like to use the boat. If pulling the riser doesn't yield anything, would it be ok to install the 140 degree thermostat as a stopgap? If that'd get me through the week, then I can pull the outdrive after the vacation to further track down root cause. But fingers crossed I'll find a clog in the riser...

Thanks! I'll report back what I find.

 

[Scott Danforth]

I would be busting your hump this week to get the boat sorted prior to vacation. the worst thing in the world is to have the whole family at the lake watching you tear into the motor while tied off at the dock.

BTDT, own the tee shirt

 

[Blintzbug]

Yeah, I hear you, I definitely don't want to be tearing things apart next week. I purchased the riser gaskets and will be pulling it this weekend. Fingers crossed that there's a blockage there that I can clear. I also purchased a 140 degree t-stat as a last resort. I don't yet have an outdrive jack so pulling the drive will have to wait until I can bring it in to the shop or until I purchase a jack. Worst case scenario we put the boat up and enjoy the kayaks/canoes

Thanks for all the info!

 

[Scott Danforth]

no need for an outdrive jack, you have two hands, and a block of wood.

 

[RCSConstruction]

So you were running too cold, put in a stat and now you're higher? I would question the T-stat. Try another one or boil the one you have with an ACCURATE thermometer. 180-190 is correct for an automobile T-stat.

 

[GuilT]

From the Volvo_Penta_3.0_GS_SX_Owners_Manual

I am paranoid with running temperature after seizing my engine within 6 months of a full rebuild. My temp gauge seems to indicate 180 at idle but if I take a reading of the sender with a multimeter (make sure you disconnect the gauge wire if you do), I get 107 ohm which corresponds to 173F based on a logarithmic extrapolation of the specs.



Good luck.