Thermostat question

[maddog2]

Can I run my 1992 Mercruiser 4.3LX without the thermostat? I don't know the consequences of running the engine without the thermostat. I can only guess that it may take a while longer to warm up. Since the engine doesn't have a heater core like a car does for heat, is it really nessessary?

Someone told me in an earlier post that the engine was designed to run at certain temperatures. I can understand that.

My engine is currently being replaced with a remanufactured long block. The mechanic says he doesn't use a thermostat.
Should I have one installed in my new engine?

Please, only Mods or certified Marine mechanics answer my question.
I don't want to be led astray by somones opinion or guess.

James in NC
High Rock Lake

 

[meesh]

Re: Thermostat question

Don, you tell him, he wont believe me!

 

[maddog2]

Re: Thermostat question

Don, you tell him, he wont believe me!

Hey, I apologise. I dont know everyone here and just wanted to find out what, if anything would happen. I remember getting information on another post about water pump hoses being too hot.

I don't mean to underestimate anyones advice given. Im sure you know what you are talking about on here. I just wanted to know what other members of this forum had to offer.

I didn't see anything in the manual concerning the use of the thermostat or lack of use.

I may have just overlooked what the manual said.

James.

 

[meesh]

Re: Thermostat question

Sorry, didn't mean to come off so harsh. Yes you need one, without temperature regulation you can run the extremes of overheating or even running cold and gumming up your crankcase. Remember, Mercruiser put it there for a reason. That mechanic gave you really bad advice.

 

[HT32BSX115]

Re: Thermostat question

Can I run my 1992 Mercruiser 4.3LX without the thermostat? I don't know the consequences of running the engine without the thermostat. I can only guess that it may take a while longer to warm up. Since the engine doesn't have a heater core like a car does for heat, is it really nessessary?

Someone told me in an earlier post that the engine was designed to run at certain temperatures. I can understand that.

My engine is currently being replaced with a remanufactured long block. The mechanic says he doesn't use a thermostat.
Should I have one installed in my new engine?

Please, only Mods or certified Marine mechanics answer my question.
I don't want to be led astray by somones opinion or guess.

James in NC
High Rock Lake

It sounds like you don't have a "certified marine mechanic" working on your engine


You need to have a thermostat to run your engine on a permanent basis. It will run far too cold if you don't. Running any engine too cold will screw up the combustion. This is not rocket surgery.

It's not nearly as critical on a carbed engine..... (an EFI engine will run far too rich if it's never allowed to warm up)

There's no reason to run without it. They almost never fail (My last boat was had a 66 Mercruiser engine in it..... Original t-stat)

Here's what they say at http://www.sterndrives.com/overheating_problem.html

If you start your engine while sitting at the dock and you let the engine warm up and you notice that your temp steadily climbs and climbs, you might have a bad thermostat. Usually, when first started, it is a good idea to watch the gauges and monitor the temp. Watch the temp gauge as the engine warms up. The temp will usually climb just a little above the normal operating temp and then it will drop down a little when the thermostat opens up. That is normal and it confirms that the therm is opening OK.
If your thermostat is sticking, replace it. NEVER run the engine without a thermostat installed or you will cause severe engine damage.

[emphasis mine]

How much convincing do you need? Tell the guy to put the correct t-stat in the engine.


You can get the thermostat at NAPA....They don't cost much.


Regards,

Rick

 

[maddog2]

Re: Thermostat question

Sorry, didn't mean to come off so harsh. Yes you need one, without temperature regulation you can run the extremes of overheating or even running cold and gumming up your crankcase. Remember, Mercruiser put it there for a reason. That mechanic gave you really bad advice.

Thank you. I will tell the mechanic to please put a new thermostat back in when he gets the new engine block next week.

I can't wait to go back out on the lake!!!

James in NC
High Rock Lake

 

[IVAZ]

Re: Thermostat question

Can I run my 1992 Mercruiser 4.3LX without the thermostat? I don't know the consequences of running the engine without the thermostat. I can only guess that it may take a while longer to warm up. Since the engine doesn't have a heater core like a car does for heat, is it really nessessary?

A heater core on a car does not provide heat for it. Its what lets you regulate temp on your AC and heater. I know its not relevant to your question but I had to clear that up.

 

[bruceb58]

Re: Thermostat question

A thermostat also regulates the flow of water as it circulates in the engine. Without a thermostat you will actually have hot spots in the heads.