Engine temp issue

[agallant80]

I am having a strange issue with my engine temp. Its all over the place. It will heat up to about 180 then drop down to 100 then heat up to 180 again. By the end of the trip on Friday the boat was running at 100. Any ideas?

 

[Volphin]

Re: Engine temp issue

First things first. Verify the problem. You are never going to run at 100. 180 is correct reading. Your sending unit connection is loose or the gauge is losing ground connectivity. Verify the actual temp with a temp gun pointed at the sender. Are you running closed cooling or raw water?

PS: Boated around Cape Lookout a few years ago. It required two anchors! LOL

 

[tpenfield]

Re: Engine temp issue

Yup, at this point I would be checking the wiring at the gauge and the sender.

Aren't new boats fun?!?!

 

[searayman11235]

Re: Engine temp issue

I am having a strange issue with my engine temp. Its all over the place. It will heat up to about 180 then drop down to 100 then heat up to 180 again. By the end of the trip on Friday the boat was running at 100. Any ideas?

Hey There . I Think I Have The Solution To Your Problem. Step 1 - Replace The Temp Sender (Do Yourself A Favor And Eliminate Yourself From False Readings.) Then Once That Is Done Trim Your Drive Up And Look At You Water Intake On The Lower Unit Of The Drive. Make Sure There Is No Crud And Growth In The Water Intake If There Is Then Scrape It Of And Inspect The Intake Holes And Make Sure Nothing Is Inside Of Them . If So Then Take A Drive Pin And Scrape The Holes Out Of Dirt. Step 2- Inspect The Heat Ex changer And Once Again Make Sure There Is No Sand , Sea Weed , Dirt Or Rust Build Up Inside. Once Again If So Then Flush The Heat Ex changer. Step 3 - Take Saltaway And Flush Your Engine With It. This May Free Any Salt Build Up Inside Your Cooling System. Step 4 - Take Apart Your Risers And Inspect For Rust Or Dirt Build Up Inside That May Stricken The Water Flow Inside . Note Manifolds Have To Be Replaced Every 3-4 Years. If You Have Done All Of That And Still Nothing Is Helping Then Replace The Impeller In The Engine And In The Drive And That Should Do It. If Problem Still Occurs Then You Must Let A Certified Marine Technician Look At It. There Is No Joke When Playing Around With Bad Engine Temp . This Has To Be Resolved Or Don't Use The Boat Because In The End It May Cause You To Bust Out Another Thousand For A New Engine. Hope This Helped . Let Me Know How It Goes Thanks .

 

[tank1949]

Re: Engine temp issue

Hey There . I Think I Have The Solution To Your Problem. Step 1 - Replace The Temp Sender (Do Yourself A Favor And Eliminate Yourself From False Readings.) Then Once That Is Done Trim Your Drive Up And Look At You Water Intake On The Lower Unit Of The Drive. Make Sure There Is No Crud And Growth In The Water Intake If There Is Then Scrape It Of And Inspect The Intake Holes And Make Sure Nothing Is Inside Of Them . If So Then Take A Drive Pin And Scrape The Holes Out Of Dirt. Step 2- Inspect The Heat Ex changer And Once Again Make Sure There Is No Sand , Sea Weed , Dirt Or Rust Build Up Inside. Once Again If So Then Flush The Heat Ex changer. Step 3 - Take Saltaway And Flush Your Engine With It. This May Free Any Salt Build Up Inside Your Cooling System. Step 4 - Take Apart Your Risers And Inspect For Rust Or Dirt Build Up Inside That May Stricken The Water Flow Inside . Note Manifolds Have To Be Replaced Every 3-4 Years. If You Have Done All Of That And Still Nothing Is Helping Then Replace The Impeller In The Engine And In The Drive And That Should Do It. If Problem Still Occurs Then You Must Let A Certified Marine Technician Look At It. There Is No Joke When Playing Around With Bad Engine Temp . This Has To Be Resolved Or Don't Use The Boat Because In The End It May Cause You To Bust Out Another Thousand For A New Engine. Hope This Helped . Let Me Know How It Goes Thanks .

Boatingat13 provides good advice. Don't know if yours is raw water or closed system. Add cleaning contacts at sender and guage and test line with om-meter and inspect thermostat. I never store my dual MC is salt water and still have headaches. Saltwater and iron don't work well!

 

[searayman11235]

Re: Engine temp issue

Boatingat13 provides good advice. Don't know if yours is raw water or closed system. Add cleaning contacts at sender and guage and test line with om-meter and inspect thermostat. I never store my dual MC is salt water and still have headaches. Saltwater and iron don't work well!

thanks , i think he has one of the older water cooling system such as raw water cooling , but i may be wrong.

 

[QC]

Re: Engine temp issue

but i may be wrong.

You are wrong. He has a brand new Mercruiser closed cooling system. No time yet for 90% of the posted issues to develop. Remember to look at the OP's signature or profile for clues

 

[scarpint]

Re: Engine temp issue

2013? With all due respect, I'd be skipping the forum and contacting your dealer.

 

[agallant80]

Re: Engine temp issue

Hi everyone.

Raw water cooling
No crud blocking the inlets
boat lives on a trailer, I have instpected the elements I can not find growth etc on it.

The only thing I can think of is I sucked up a bunch of sand a few weeks ago. It stuck the thermostat open. I took it off, cleaned it up and poored hot water over it several times and watched it open and close. Perhaps I did not attach the temp sender plug to the temp sender snug enough. I will have to look at it.

Any thoughts on the raw water impeller? Perhaps I sucked enough sand through it to damage it? Could that cause the sparatic temp readings?

 

[achris]

Re: Engine temp issue

Did you use a proper OEM thermostat housing gasket, or a cheapo one from an auto shop?

Chris......

 

[agallant80]

Re: Engine temp issue

I used the auto parts store one. They changed the style to an o-ring instead of the diamond shaped paper gasket.

 

[achris]

Re: Engine temp issue

And there's where your gauge problem is... The OEM gasket has continuity lugs in it. The new one you got, don't.... Replace the gasket with the OEM gasket and the problem should go away...

Merc part number is 27-530451

Chris.....

 

[agallant80]

Re: Engine temp issue

Makes total sense. Thank you Chris! I just ordered a few of them.

 

[tank1949]

Re: Engine temp issue

Makes total sense. Thank you Chris! I just ordered a few of them.

Had same problem with v8 MC after dianosis numerous OTHER problems and having to replace stat gasket numerous times. Marine gasket has special brass connecting point to make sure good ground. Destroyed a couple before ironing out other issues. So, I just connected heavy copper wire via ss hose clamp wrapped around a contact point on stat housing. Best way is go marine OEM, but we were trying to debug other issues and decided this way was most efficient and I could use auto gasket in future. I believe that you could also drill into motor lifting lug for good contact point, if you have one on stat housng. Mine do..

 

[agallant80]

Re: Engine temp issue

I ordered three of them so I should be good for a while. One to replace the auto gasket, one for the end of the year when I pull the thermostat to dump antifreeze, and one for I don't know when.

 

[tank1949]

Re: Engine temp issue

Had a friend overly cautions one time who rigged up hose connection "T" to dump in pure antifreeze. I argued it getting past stat, but he swore by it. I just install light in bilge, but I suspect your way keeps rust at bay a lot better. Good luck!

 

[achris]

Re: Engine temp issue

I guess you're all talking about winterizing the engine. (Don't need to here. Currently in the depths of winter, and I plan on fishing the next few days.. ).. Anyway, winterizing. We see many, many :facepalm: threads here at the beginning of each summer along the lines of ... I winterized my engine by filling with anti-freeze, now the engine block is cracked....

One very simple, easy to follow, completely 100% guaranteed way to avoid a cracked block.... (3 simple words).... AIR...DON'T...FREEZE... Forget filling with antifreeze and all trouble (not to mention risk) that entails, just pull the plugs out of the side of the block, the ones under the manifolds (make sure they're clear by using a bit of wire or a small screwdriver), and the large water hose on the front of the engine and the job's done, finished, complete.

I've also hear of sitting a light bulb in the bilge... Works really well, until the power goes out :facepalm:. Then you have a 100% guarantee of a cracked block....

Chris....

 

[tank1949]

Re: Engine temp issue

I guess you're all talking about winterizing the engine. (Don't need to here. Currently in the depths of winter, and I plan on fishing the next few days.. ).. Anyway, winterizing. We see many, many :facepalm: threads here at the beginning of each summer along the lines of ... I winterized my engine by filling with anti-freeze, now the engine block is cracked....

One very simple, easy to follow, completely 100% guaranteed way to avoid a cracked block.... (3 simple words).... AIR...DON'T...FREEZE... Forget filling with antifreeze and all trouble (not to mention risk) that entails, just pull the plugs out of the side of the block, the ones under the manifolds (make sure they're clear by using a bit of wire or a small screwdriver), and the large water hose on the front of the engine and the job's done, finished, complete.

I've also hear of sitting a light bulb in the bilge... Works really well, until the power goes out :facepalm:. Then you have a 100% guarantee of a cracked block....

Chris....

Achris,, that is a real good idea, but how do you get traped water out of exhaust manifolds on Chevy v8s? Put a little antifreeze into via riser hose, ten drain excess in block?????


Jim

 

[achris]

Re: Engine temp issue

There won't be any trapped water in the manifolds. The plugs/hose connections are at the bottom, and unless there's some new water out there that has learned to defy gravity, it'll all fall out of the hole....

 

[NHGuy]

Re: Engine temp issue

I defied gravity once. Then it grabbed me even harder and slammed me back to earth.
But seriously, if you remove the drains below the exhaust manifolds, remove the 2 petcocks in the block, and probe the 4 of them with a coat hanger or something, then all that's left is the water circulation pump hose. I also pull off the power steering cooler water line just in case.
The problem with anti freeze is it can be diluted by residual water and not have enough freeze resistance in spots. Don't chance it.