TAMD31P overheating alarm

[captricklilpinky]

I have 2-TAMD31P engines, the overheating alarm on the one engine sounds before the engine reaches 180 degrees. When I put an inferred detector on the engine it reads 167 degrees almost what the temperature gauge reads. I tested the other engine and got the same results. My question is where is the alarm sensor located and is there another test to verify it is faulty? Is there a special tool needed to replace the sensor?

 

[alldodge]

Re: TAMD31P overheating alarm

Check for corresion on connectors but it's my understanding that there are two sensors. They are either both on the thermostat housing or the temp switch is on the exhaust elbow and the solid color wire goes to the gauge and the one with the stripe is the overtemp alarm. Most the time it is the overtemp.

Found a europe site but may not match yours
Volvo Penta Exploded view / schematic Thermostat housing AD31L-A, AD31P-A, TAMD31L-A, TAMD31M-A, TAMD31P-A, TAMD31S-A, TMD31L-A - MarinePartsEurope.com

 

[captricklilpinky]

Re: TAMD31P overheating alarm

Check for corresion on connectors but it's my understanding that there are two sensors. They are either both on the thermostat housing or the temp switch is on the exhaust elbow and the solid color wire goes to the gauge and the one with the stripe is the overtemp alarm. Most the time it is the overtemp.

Found a europe site but may not match yours
Volvo Penta Exploded view / schematic Thermostat housing AD31L-A, AD31P-A, TAMD31L-A, TAMD31M-A, TAMD31P-A, TAMD31S-A, TMD31L-A - MarinePartsEurope.com

.
I found the alarm sensor it is located on the bottom of exhaust manifold at the front. Can I relocate it to thermostat housing? There is a plug about 5 inches away from the sensor and it is located on the front of the engine.

 

[alldodge]

Re: TAMD31P overheating alarm

.
I found the alarm sensor it is located on the bottom of exhaust manifold at the front. Can I relocate it to thermostat housing? There is a plug about 5 inches away from the sensor and it is located on the front of the engine.

You probably can but I believe Volvo put it there was to protect the engine better. If you loose water flow the exhaust will be the first to heat up and let you know. If the sensor is working correctly it may be telling you there is a restriction somewhere in the water going to the exhaust. If the sensor is not working correctly then it may just need replacing. Your call, your engine

 

[captricklilpinky]

Re: TAMD31P overheating alarm

The exhaust manifold is freshwater cooled and it flows to the thermostat housing. I am thinking that it would be easier to service again if it is in the front of the engine. It still is before the temperture gauge sensor.

 

[alldodge]

Re: TAMD31P overheating alarm

The exhaust manifold is freshwater cooled and it flows to the thermostat housing. I am thinking that it would be easier to service again if it is in the front of the engine. It still is before the temperture gauge sensor.

If your engine uses a closed cooling system then the exhaust sensor measures fresh water flow temp. If it is open then the water will flow through the thermostat housing otherwise it doesn't. I see it being rare for the sensor to fail but it is your call.

All the best, and have a great boating season

 

[captricklilpinky]

Re: TAMD31P overheating alarm

I am going to have a tech from Volvo look at this problem next week see what he reccomends. After discussing this with you it sounds like maybe the thermostats are not opening soon enough and that is why the alarm goes off before the engine temp gauge reaches 180 degress. Anyway when we solve this problem I will get back to you. Thanks

 

[alldodge]

Re: TAMD31P overheating alarm

Sounds like a good plan

 

[captricklilpinky]

Re: TAMD31P overheating alarm

I had the Volvo tech down to the boat and he thought the same as you that corrosion has cause the alarm to go off. After checking all connections he ruled out the connections. He proceeded to take the heat exchanger off to get to the sensor, he replaced the sensor and we sea trialed it for a 1/2 hour and the alarm never went off and the motor water temp never went over 172 degrees. We even ran the motors wide open for 2 miles and the alarms never sounded and the engines ran at 172 degrees. Cross your fingers that was the problem and all is well.