Mercruiser 4.3 V6 High Idle Temp

Hi Everyone,

After a long winter I have been carrying out some maintenance over the past couple of weeks. I put the drive back on after replacing all the seals and gasket but after running the engine for the first time since last summer I have noticed the temperature gauge raise quite quickly to higher than normal, around 200. I have only had the engine at idle running on the muffs but the boat was performing perfectly last summer?
I removed the thermostat and checked it opens when exposed to boiling hot water.
The manifolds are warm but not too hot to touch and the water exiting the boat is only slightly warm?

I was wondering whether anyone had any suggestions to try tomorrow or experienced this issue before?

Are the temperature gauge and warning alarm on seperate electrical circuits and work independently to each other?

Thank you for any information or advice.

Dean

Re: Mercruiser 4.3 V6 High Idle Temp

What is your year and serial #?

Re: Mercruiser 4.3 V6 High Idle Temp

NHGuy said:

What is your year and serial #?

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Hi, the year is August 2009 and serial number 1A600217.

Thanks for any help!

Dean

Re: Mercruiser 4.3 V6 High Idle Temp

Have you replaced the raw water pump impeller in the drive? That would be the first thing you should check on any marine overheat.

Are the temperature gauge and warning alarm on seperate electrical circuits and work independently to each other?

Click to expand...

Yes, they are different systems. The gauges have senders, while the alarms have switches.

Re: Mercruiser 4.3 V6 High Idle Temp

Don S said:

Have you replaced the raw water pump impeller in the drive? That would be the first thing you should check on any marine overheat.



Yes, they are different systems. The gauges have senders, while the alarms have switches.

Click to expand...

Thanks for the reply, I changed the impeller last year with genuine quicksilver, I understand these should last two seasons? I hardly used the boat last year as spent more time in hospital with two collapsed lungs, the boat was running perfect when I did use it?

If the temp gauge is saying the engine is over heating yet the alarm isn't going off is this a sign that the gauge may be faulty?

Thanks

Dean