Overheats only when turned off

[jaxs]

thats pretty much what Im seeing. The overflow reservoir hose has steam come out until all the coolant leaves the system including the radiator. I can continue to refill daily but want to fix whats going on.

I do a 50/50 mix of coolant and water.

What is that saying about "doing the same thing over and over expecting a different result"?
Keep this up and you won't need to know what causes this to happen,you will need a new engine. Diesel engines ALL DIESEL ENGINES are intolerant of overheating and start melting from the inside out. Second only to not keeping engine in powerband rpms, failure to shut down at first sign of overheating destroys more diesels than other things combined. A long nose Peterbilt can't keep on trucking while spewing steam and neither can your little Bota?
Besides that you are wasting antifreeze for no reason. It's time to stop waging and try some of the troubleshooting suggestions then report results.

 

[cthomas]

Had a customer's Ford F-350 that would only overheat when pulling a trailer. Was told it has been at several shops and no one could duplicate issue. New water pump, hoses, coolant tank, radiator cap, and anti-freeze, none of which solved issue. When he bought it in I sent him back home to get the trailer. After testing found the whole center of radiator was cool using an infrared camera. Removed the radiator and look down the fill(radiator) cap looked brand new, but cut the top off of the radiator and all the center tubes were plugged.

 

[Nicksacco]

It does sound like coolant is not circulating properly. Especially since this seems to be a new thing.

Did you check to see if the front of the radiator is plugged with grass and junk?

Something you could do (which would also benefit the machine):
1) drain all the coolant
2) remove radiator and thermostat
3) hook up a garden hose to the radiator hoses/openings one at a time (on the engine) and flush away.
There should no restrictions.

This would flush out the engine and show if anything was plugged and clean out the engine system.
After I do something like this, I also used compressed air and remove most of the residual water as well.

Then do it with the radiator. If you had or could borrow a borescope and look inside you may see build up in the radiator. The water should flow quickly and unimpeded.

I only use distilled water when mixing coolant since I have a well. I'd recommend distilled anyway.

A pressure test would be an excellent idea too. The kits are relatively cheap.

Do let us know what you decide and/or your solution please.

Examples of kits

Amazon.com : Radiator Pressure Test Kit

www.amazon.com

 

[Flintknapper]

A pressure test would be an excellent idea too.

^^^^^

Agreed.

Pressure testing both the radiator cap and then the system is something I jump straight ahead to....anytime I see overheating (not easily attributable to something obvious).

It allows you to quickly determine if the issue is with coolant loss, pressure loss or is the result of insufficient flow.

IF the system does not hold proper pressure (cap or elsewhere) then the boiling point of the coolant becomes markedly less.

IF there are no discernible leaks (coolant or pressure) then the issue is with coolant flow or head gasket, head, block.

 

[lmichael]

Are you assuming "over heat" because it's boiling at shut down? Or are you seeing an actual temperature suggesting it as well?

 

[The Evil Twin]

Is that common? when motors get older do they have this tendency if not acting this way before?

Maybe not "common" per se, but it is not rare. Older engines often have degraded cooling systems that can increase the frequency.
That said, if this is a sudden, new thing then I'd start looking at pressurizing the system after draining it. If it holds pressure for 30 min, then start pulling glow plugs. Alternatively, you could rotate the crank by hand. That will start opening up the valves in different cylinders. Any pressure leaking past the head gasket into the cylinders will ne relieved through the valves as they open.