Larson 4.3 volvo overheating issue

[Jarcher3]

so i just bought a 2001 larson 190 lxi with the 4.3 volvo I/O. Before i bought it i test drove it and it overheated. it had gotten a new motor 2 seasons ago from the PO and i chalked it up to the impeller and brought it to a mechanic before i bought it. he agreed and replaced the thermostat and impeller.

So this weekend we got it out to the lake and were idling from the launch ramp to the slip. then on the way out to open water, i noticed the temp gauge was back at the top near the red, so i let it idle for a min and then the alarm started going off.

We popped the engine cover and i felt the risers which were warm but not hot, same with the valve covers. the alternator was warmer than the rest of the things in there though. so then i started it again and there was a beeping coming form the engine bay.

Any ideas on this? im wondering (Hoping) if it may be a sensor or the Gauges.(It has The VDO gauges)

 

[Bondo]

if it may be a sensor or the Gauges

Ayuh,..... Welcome Aboard,..... The temp sender is in the t-stat housin',....

Pull the wire off it, 'n with the key "On", touch it to Ground,.....

The gauge should peg to Hot,......

The alarm switch is also in the t-stat housin', pull it's wire off, 'n Ground it, the alarm sounds,....

 

[jerryjerry05]

Get a heat ray gun.
​Under 20$
Make sure the motors not heating up.
Then pull the sensor leads to see what one activates the buzzer.
Then test and replace the sensor.

 

[bajaunderground]

That motor will also have temp sensors on each rear elbow of the exhaust. Most likely the t-stat housing wasn't 100% cleared of impeller (most likely suspect the by-pass orifice). I will say, I've been fighting the same issue to a degree and have replaced risers/impeller/thermostat/sea waterpump/fuel cell. Search over-heating issues for Volvo Penta, there is a process for trouble shooting!

 

[Jarcher3]

Sounds good, thanks everyone, i ended up taking it back to the shop that replaced the impeller to start with to let them finish their job... where are the IR heat guns? amazon? i would like to get one to have on the boat just in case..

 

[Thalasso]

Sounds good, thanks everyone, i ended up taking it back to the shop that replaced the impeller to start with to let them finish their job... where are the IR heat guns? amazon? i would like to get one to have on the boat just in case..

Harbor Freight.

 

[Jarcher3]

Just to check in with an update on this.

It turned out to be the temp sender from the T-stat.

Got it all replaced and now the temp holds steady, its running higher than i would like but it has been steady over 5 days out on the water.