Check Engine Alarm

[wilsontcu]

Have a 2013 Cobalt 220 and about a month ago the check engine alarm went off from dash indicating overheating. The engine did seem to hot, we had only been idling or running slow for about 8 to 10 minuets. I put a new impeller in and put new thermostat including exhaust manifold thermostats. The engine idles good now and is not overheating BUT after about 8 min the alarm is still sounding to check engine. Any ideas? Is there an alarm re-set? I have had a mechanic out to check all things he can think of, engine is running good, all fluids are fine but cant get the alarm to stop?

Help!

[AsLan7]

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Hey wilsontcu...so glad you found us!

Maybe folks here can help although you are checking all the right areas. Merc or VP?

Older generations can be fooled by the depth alarm which sounds similar to an engine alarm. You have a check engine message as well correct?

Any pics? Keep us posted with what the marine tech discovers.

And welcome aboard mate.

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[Big Block Power]

Is this merc or volvo?
It should be setting a code if it's engine related. Merc it could be drive fluid reservoir low. Sounds like I would try a different tech

[wilsontcu]

So it is a Volvo Penta and the Check Engine message is displaying when alarm sounds then showing engine heat. When alarm first went off a month ago the engine was defiantly overheating, exhaust was super hot and engine running up to 150 degree within minuets at idle. I first took the impeller which was not really in bad shape but I replaced it anyway. the thermostat was real bad so I replaced that, this fixed the issue. Engine is running cool now and everything checks out I just cant get the check engine alarm to stop sounding. Do you know if there is a reset? It only wants to sound when sitting in neutral or idling slowly. I took boat out and opened up, temp never got over 160, does not feel or smell hot. All fluids check out. I don't have the Volvo engine book so I cant really be confident that I know where these sensors for overheating are or I would detach it to see if that stops the check engine alarm. My thoughts are there is an alarm reset that I don't know about or I am chasing the wrong issue as the cooling system is now functioning.

[Big Block Power]

I don't know of any reset. Never have.
It could be a bad temp Sensor still on the exhaust manifolds. I think that's common on some of these that have had issues from what I read on here from other members that had warnings.

[bruceb58]

This is why I own a Rinda Diacom. Makes things like this was easier to diagnose. Yes it is expensive... but so is the pain taking the boat to a dealer and letting it sit and getting a big repair bill.