How to burp air out of cooling system Yanmar 2gm20f?

[Jecemis]

Hi all ~

Is there an easy way to burp out air that may be in the coolant system? I'm having an issue w/ overheating. I believe it's coming from the fresh water side of the system as the coolant/antifreeze was empty.

I've since added about a gallon and half of premixed coolant/anti freeze but I'm still getting an overheat alarm after running the engine several minutes. I didn't add the coolant/antifreeze w/ the cap off and engine running so I think there may be air in the line. I wanted to try to burp it out before exploring other potential problems.

 

[jssailem]

Burping is not likely the problem.
You lost the coolant (it leaked out - it does not just evaporate). You need to look for the leak.
Check all hoses. Check the pump. Check the engine block.... Somewhere you will find a drip or gusher of coolant. Fix that and then check again. Look at the Heat Exchanger. Do you find the part leaking?
Once you stop the leaks, and the problem continues, then you look for a blockage. It is a tedious process but you can do it.
If you give up you can hire a boat worker to look for you. This will cost buck$ and you will not learn your engine.
When you identify the issue or think you have, come back and ask how to solve what you discovered.

 

[Jecemis]

Thanks for the reply... I've been running it while observing it hoping to see if it leaks since discovering it was empty after being on the hard all winter. I haven't found any so far and the coolant level seems to be the same since I've re-added it. But you are correct that it doesn't just evaporate. I guess need to look harder.

 

[jssailem]

I was having a similar issue with my Perkins. Running hot. a little seepage that required topping off the coolant. Then I began to see a fine mist on the pump side of the engine. This finally became a steam spray and I shut down the engine. Discovered that the pump ( which turns because of the v belt) had begun to leak from a bad seal. The seal was bad because the bearing had failed. When the bearing failed the pulley wobbled and damaged the alternator bolts.
I swore some one or thing had sabotaged my engine. I removed the pump and replaced it with a new one. I repaired the alternator bolts and bought a new belt. Put it back together, filled with coolant. Rocked the boat back and forth hearing the bubbles of trapped air escape into the coolant tank. Refilled the tank. Started the engine. Has run at 155 degrees for the past 18 months.
You can do it.

 

[jssailem]

Here is a link that might give you additional info.
https://forums.sailboatowners.com/index.php?threads/burping.185718/#post-1378793

 

[Terry Cox]

You can do it.

Sheesh John, you need to start charging consulting fees.

 

[jssailem]

Thanks Terry.. I've been told free advise is sometimes as good as what you pay for it...

 

[Benny17441]

Assuming you have put new coolant on the fresh water side of the exchanger and ran the engine to prime the pump and topped the system; even with the presence of a leak the engine should not be overheating in short order. Start from scratch and check the raw water system and impeller. Don't make assumptions, conduct a complete diagnostic check on the whole system. Make sure the engine oil level is good.

 

[Jecemis]

Thanks Terry.. I've been told free advise is sometimes as good as what you pay for it...

Great advice and thank you for the encouragement. I have so many little boat projects needing my attention that it's a bit overwhelming at times.

There was indeed a leak! I thoroughly examined the raw water side, replaced the impeller, etc, but the leak was actually caused by me. My hot water heater rusted out, and last winter I bypassed it so that I could winterize the plumbing. I didn't realize that my hot water heater was electric and also ran off the motor's cooling system. I thought the hoses I hooked up to the plumbing came from the water tank but I learned today they were actually connected to the motor's cooling system.

So I closed that loop and re-added coolant/anti-freeze and she's now running perfectly. Ran her for about an hour total today without any issue. Now I need to replace the galley plumbing since it had toxic anti-freeze flowing through the lines.

 

[Gunni]

Suggestion: Save yourself some work. Flush your plumbing well with fresh water and spend your time flushing and replacing your engine coolant with one of the new propylene glycol engine coolants from Fleetguard or Starbrite. Never worry about toxic antifreeze in your potable system again.