5.0L GL overheating

[33993]

OK, Here's my deal. . . I have a 2003 volvo penta 5.0L GL that I chewed up the impeller on. I changed the impeller, thermo, and cleaned out the hoses and scraped out the drains on both sides of the exhaust. I started the engine and after a while it began to creep up to 150f. Then the alarm came on. Does the alarm need to be reset or is the thermo giving me the wrong reading? Why would the alarm come on already? Any help would be appreciated.

 

[Don S]

Re: 5.0L GL overheating

The alarm switch may have failed. You can verify the temp gauge, sender and switch by first verifying what the temp actually is. Get one of those IR temp guns.
Either the alarm switch or the gauge sender is telling you wrong.

 

[33993]

Re: 5.0L GL overheating

Hey tanks for the snappy response Dan. I have to play dad for the rest of the day so I'll get back with my response asap. Where exactly do I point the temp gun for the most accurate reading?

 

[Don S]

Re: 5.0L GL overheating

Point it right at the base of the sender and switch.

 

[33993]

Re: 5.0L GL overheating

OK, so here's the update to my situation: I changed both the temp sensor and the alarm switch, then started it. As soon as it got up to 100 degrees the alarm started to sound again. I shut it down. After a while I started it again and no alarm. The temp stayed at around 150 -175.

 

[Don S]

Re: 5.0L GL overheating

What did you put on the threads of the alarm switch?

 

[33993]

Re: 5.0L GL overheating

Nothing. . . .Am I supposed to?

 

[Don S]

Re: 5.0L GL overheating

You didn't overtighten it did you, that can really damage sensors and switches. Just a light coat of sealer is all it takes, just to lube the threads a little. NO TEFLON TAPE.

 

[33993]

Re: 5.0L GL overheating

Thanks for your help Don. The sensor that needed to be changed out was on top of the exhaust. After I changed that I putted around the canals for a while until the temp came up to NOT and the alarm did not turn on. The temp stayed around 150-155 for a half an hour so I guess I'm ok.