Keep blowing up radiators

[Hugo Habicht]

There is still a problem with your radiator cap. It should limit the pressure building up before damage is done to the radiator.

In your first post you wrote nothing points to the head gasket. Get a CO2 test kit, cheap, simple, fast.

 

[Trash Panda]

“Found nothing to suggest a head gasket”

“Turns out, it was a head gasket”

 

[Five Acres]

I am also trying to track down the cause of high heat levels nearing the red zone.

Will attempt some of the tests/suggestions:

Belt tightening

Observation of fluid in radiator

Thermostat (it seems to be opening as both lower and upper hoses are hot)

New coolant as water has been added over time.

Is there an easy means to test for head gaskets failure or water pump failure?

Any suggestions?

 

[Five Acres]

It was a blown head gasket.

Curious to know the cost of that repair?

 

[Russell King]

Have you cleaned the exterior of the radiator fins really well?

 

[DaveFromMi]

I worked at an auto company several years. A new no leak (no jiggle pin) thermostat was being tested for production and had made it in several test vehicles. We had reports of heater and rad hoses blowing off and dumping coolant. Not sure of the driving pattern, but it was aggressive.
Basically, due to no venting (no jiggle pin), it would take excessive time for the stat to respond to hot coolant. They tried to make the stat work in a lab and eventually changed the spring and pellet to improve controllability. The problem was it responded to cooler (below opening) temps quick and the stat slammed shut resulting in a water hammer condition, blowing hoses off. The engine guys wanted us to provide braided steel hoses, lol.
End result was they went back to the old stat.

 

[whitetiger]

If I ever told one of my engin builders I had a thermostat in one of there engines I’d probably no I know I’d get the biggest wrench thrown at me.

There is a slight difference between a gas race engine and a diesel engine. A good share of diesel engines use a blanking thermostat, which, when open, keeps the coolant from circulating in a loop between the cylinder head and block, skipping the radiator.

In this case, I don't think your engine uses one.

 

[mikester]

Hi I’d like to thank you in advance for taking the time to help me with this. I have a ZD326 zero turn that is my baby. It has just over 640hr it’s a 2011 and it gets a full service and cleaning after every use. So lack of maintenance is not an issue. I had an overheating issue about a year ago so I replaced the radiator with a good flush of the system. It’s been working great tell a couple of weeks ago when it sounded the overheating alarm and I pulled under a tree. I shut it off as the radiator blew up. Split the top open. As soon as the alarm went off I looked at the gage it was just about in the red maybe an 1/8 from it. Now the radiator was not clogged. The thermostat has been out of it for a while. I’m in fl no need for one here. I replaced the radiator with a new one. New cap with the recommended coolant. Ran the mower for about 10 minutes to check for any pressure buildup. Found nothing to suggest a head gasket. Started mowing and around the 10 minute mark I looked at the gage it was just about to the red and before I could park it the alarm sounded and the radiator split the top wide open again. I’m at a loss need help finding the problem and a fix.

When did you last replace your fan/alternator belt?

If the belt is slipping you will experience overheating and battery problems.